xinyin025/hello-algo
1
0
Fork 0
mirror of https://github.com/krahets/hello-algo.git synced 2026-07-09 14:06:06 +00:00
Code Issues Packages Projects Releases Wiki Activity

deploy

Browse Source
This commit is contained in:
krahets
2023-08-20 14:52:42 +08:00
parent 96fded547b
commit 26a2e7f171
42 changed files with 234 additions and 230 deletions
Download Patch File Download Diff File Expand all files Collapse all files
chapter_appendix/installation/index.html
+1 -1
View File
@@ -3533,7 +3533,7 @@
</ol>
<h2 id="1613-cc">16.1.3 &nbsp; C/C++ 环境<a class="headerlink" href="#1613-cc" title="Permanent link">&para;</a></h2>
<ol>
<li>Windows 系统需要安装 <a href="https://sourceforge.net/projects/mingw-w64/files/">MinGW</a>（<a href="https://blog.csdn.net/qq_33698226/article/details/129031241">配置教程</a>），MacOS 自带 Clang 无需安装。</li>
<li>Windows 系统需要安装 <a href="https://sourceforge.net/projects/mingw-w64/files/">MinGW</a>（<a href="https://blog.csdn.net/qq_33698226/article/details/129031241">配置教程</a>），MacOS 自带 Clang 无须安装。</li>
<li>在 VSCode 的插件市场中搜索 <code>c++</code> ，安装 C/C++ Extension Pack 。</li>
<li>（可选）打开 Settings 页面，搜索 <code>Clang_format_fallback Style</code> 代码格式化选项，设置为 <code>{ BasedOnStyle: Microsoft, BreakBeforeBraces: Attach }</code> 。</li>
</ol>
chapter_array_and_linkedlist/array/index.html
+2 -2
View File
@@ -3926,7 +3926,7 @@
</div>
<h3 id="4">4. &nbsp; 删除元素<a class="headerlink" href="#4" title="Permanent link">&para;</a></h3>
<p>同理，如果我们想要删除索引 <span class="arithmatex">\(i\)</span> 处的元素，则需要把索引 <span class="arithmatex">\(i\)</span> 之后的元素都向前移动一位。</p>
<p>请注意，删除元素完成后，原先末尾的元素变得“无意义”了，所以我们无需特意去修改它。</p>
<p>请注意，删除元素完成后，原先末尾的元素变得“无意义”了，所以我们无须特意去修改它。</p>
<p><img alt="数组删除元素" src="../array.assets/array_remove_element.png" /></p>
<p align="center"> 图：数组删除元素 </p>
@@ -4571,7 +4571,7 @@
<h2 id="412">4.1.2 &nbsp; 数组优点与局限性<a class="headerlink" href="#412" title="Permanent link">&para;</a></h2>
<p>数组存储在连续的内存空间内，且元素类型相同。这包含丰富的先验信息，系统可以利用这些信息来优化操作和运行效率，包括：</p>
<ul>
<li><strong>空间效率高</strong>: 数组为数据分配了连续的内存块，无需额外的结构开销。</li>
<li><strong>空间效率高</strong>: 数组为数据分配了连续的内存块，无须额外的结构开销。</li>
<li><strong>支持随机访问</strong>: 数组允许在 <span class="arithmatex">\(O(1)\)</span> 时间内访问任何元素。</li>
<li><strong>缓存局部性</strong>: 当访问数组元素时，计算机不仅会加载它，还会缓存其周围的其他数据，从而借助高速缓存来提升后续操作的执行速度。</li>
</ul>
chapter_array_and_linkedlist/linked_list/index.html
+1 -1
View File
@@ -3523,7 +3523,7 @@
<h1 id="42">4.2 &nbsp; 链表<a class="headerlink" href="#42" title="Permanent link">&para;</a></h1>
<p>内存空间是所有程序的公共资源，在一个复杂的系统运行环境下，空闲的内存空间可能散落在内存各处。我们知道，存储数组的内存空间必须是连续的，而当数组非常大时，内存可能无法提供如此大的连续空间。此时链表的灵活性优势就体现出来了。</p>
<p>「链表 Linked List」是一种线性数据结构，其中的每个元素都是一个节点对象，各个节点通过“引用”相连接。引用记录了下一个节点的内存地址，我们可以通过它从当前节点访问到下一个节点。这意味着链表的各个节点可以被分散存储在内存各处，它们的内存地址是无需连续的。</p>
<p>「链表 Linked List」是一种线性数据结构，其中的每个元素都是一个节点对象，各个节点通过“引用”相连接。引用记录了下一个节点的内存地址，我们可以通过它从当前节点访问到下一个节点。这意味着链表的各个节点可以被分散存储在内存各处，它们的内存地址是无须连续的。</p>
<p><img alt="链表定义与存储方式" src="../linked_list.assets/linkedlist_definition.png" /></p>
<p align="center"> 图：链表定义与存储方式 </p>
chapter_array_and_linkedlist/list/index.html
+1 -1
View File
@@ -3509,7 +3509,7 @@
<h1 id="43">4.3 &nbsp; 列表<a class="headerlink" href="#43" title="Permanent link">&para;</a></h1>
<p><strong>数组长度不可变导致实用性降低</strong>。在实际中，我们可能事先无法确定需要存储多少数据，这使数组长度的选择变得困难。若长度过小，需要在持续添加数据时频繁扩容数组；若长度过大，则会造成内存空间的浪费。</p>
<p>为解决此问题，出现了一种被称为「动态数组 Dynamic Array」的数据结构，即长度可变的数组，也常被称为「列表 List」。列表基于数组实现，继承了数组的优点，并且可以在程序运行过程中动态扩容。我们可以在列表中自由地添加元素，而无需担心超过容量限制。</p>
<p>为解决此问题，出现了一种被称为「动态数组 Dynamic Array」的数据结构，即长度可变的数组，也常被称为「列表 List」。列表基于数组实现，继承了数组的优点，并且可以在程序运行过程中动态扩容。我们可以在列表中自由地添加元素，而无须担心超过容量限制。</p>
<h2 id="431">4.3.1 &nbsp; 列表常用操作<a class="headerlink" href="#431" title="Permanent link">&para;</a></h2>
<h3 id="1">1. &nbsp; 初始化列表<a class="headerlink" href="#1" title="Permanent link">&para;</a></h3>
<p>我们通常使用“无初始值”和“有初始值”这两种初始化方法。</p>
chapter_array_and_linkedlist/summary/index.html
+1 -1
View File
@@ -3450,7 +3450,7 @@
<div class="admonition question">
<p class="admonition-title">在 Python 中初始化 <code>n = [1, 2, 3]</code> 后，这 3 个元素的地址是相连的，但是初始化 <code>m = [2, 1, 3]</code> 会发现它们每个元素的 id 并不是连续的，而是分别跟 <code>n</code> 中的相同。这些元素地址不连续，那么 <code>m</code> 还是数组吗？</p>
<p>假如把列表元素换成链表节点 <code>n = [n1, n2, n3, n4, n5]</code> ，通常情况下这五个节点对象也是被分散存储在内存各处的。然而，给定一个列表索引，我们仍然可以在 <span class="arithmatex">\(O(1)\)</span> 时间内获取到节点内存地址，从而访问到对应的节点。这是因为数组中存储的是节点的引用，而非节点本身。</p>
<p>与许多语言不同的是，在 Python 中数字也被包装为对象，列表中存储的不是数字本身，而是对数字的引用。因此，我们会发现两个数组中的相同数字拥有同一个 id ，并且这些数字的内存地址是无需连续的。</p>
<p>与许多语言不同的是，在 Python 中数字也被包装为对象，列表中存储的不是数字本身，而是对数字的引用。因此，我们会发现两个数组中的相同数字拥有同一个 id ，并且这些数字的内存地址是无须连续的。</p>
</div>
<div class="admonition question">
<p class="admonition-title">C++ STL 里面的 std::list 已经实现了双向链表，但好像一些算法的书上都不怎么直接用这个，是不是有什么局限性呢?</p>
chapter_backtracking/subset_sum_problem/index.html
+1 -1
View File
@@ -3518,7 +3518,7 @@
</ul>
<h3 id="1">1. &nbsp; 参考全排列解法<a class="headerlink" href="#1" title="Permanent link">&para;</a></h3>
<p>类似于全排列问题，我们可以把子集的生成过程想象成一系列选择的结果，并在选择过程中实时更新“元素和”，当元素和等于 <code>target</code> 时，就将子集记录至结果列表。</p>
<p>而与全排列问题不同的是，<strong>本题集合中的元素可以被无限次选取</strong>，因此无需借助 <code>selected</code> 布尔列表来记录元素是否已被选择。我们可以对全排列代码进行小幅修改，初步得到解题代码。</p>
<p>而与全排列问题不同的是，<strong>本题集合中的元素可以被无限次选取</strong>，因此无须借助 <code>selected</code> 布尔列表来记录元素是否已被选择。我们可以对全排列代码进行小幅修改，初步得到解题代码。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="1:12"><input checked="checked" id="__tabbed_1_1" name="__tabbed_1" type="radio" /><input id="__tabbed_1_2" name="__tabbed_1" type="radio" /><input id="__tabbed_1_3" name="__tabbed_1" type="radio" /><input id="__tabbed_1_4" name="__tabbed_1" type="radio" /><input id="__tabbed_1_5" name="__tabbed_1" type="radio" /><input id="__tabbed_1_6" name="__tabbed_1" type="radio" /><input id="__tabbed_1_7" name="__tabbed_1" type="radio" /><input id="__tabbed_1_8" name="__tabbed_1" type="radio" /><input id="__tabbed_1_9" name="__tabbed_1" type="radio" /><input id="__tabbed_1_10" name="__tabbed_1" type="radio" /><input id="__tabbed_1_11" name="__tabbed_1" type="radio" /><input id="__tabbed_1_12" name="__tabbed_1" type="radio" /><div class="tabbed-labels"><label for="__tabbed_1_1">Java</label><label for="__tabbed_1_2">C++</label><label for="__tabbed_1_3">Python</label><label for="__tabbed_1_4">Go</label><label for="__tabbed_1_5">JS</label><label for="__tabbed_1_6">TS</label><label for="__tabbed_1_7">C</label><label for="__tabbed_1_8">C#</label><label for="__tabbed_1_9">Swift</label><label for="__tabbed_1_10">Zig</label><label for="__tabbed_1_11">Dart</label><label for="__tabbed_1_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
chapter_computational_complexity/index.html
+2 -2
View File
@@ -3356,8 +3356,8 @@
</div>
<div class="admonition abstract">
<p class="admonition-title">Abstract</p>
<p>复杂度犹如浩瀚的算法宇宙中的指南针。</p>
<p>它引导我们在时间与空间的维度上深入探索，寻找更优雅的解决方案。</p>
<p>复杂度犹如浩瀚的算法宇宙中的时空向导。</p>
<p>它带领我们在时间与空间这两个维度上深入探索，寻找更优雅的解决方案。</p>
</div>
<h2 id="_1">本章内容<a class="headerlink" href="#_1" title="Permanent link">&para;</a></h2>
<ul>
chapter_computational_complexity/performance_evaluation/index.html
+10 -10
View File
@@ -3426,12 +3426,12 @@
<h1 id="21">2.1 &nbsp; 算法效率评估<a class="headerlink" href="#21" title="Permanent link">&para;</a></h1>
<p>在算法设计中，我们先后追求以下两个层面的目标：</p>
<p>在算法设计中，我们先后追求以下两个层面的目标。</p>
<ol>
<li><strong>找到问题解法</strong>：算法需要在规定的输入范围内，可靠地求得问题的正确解。</li>
<li><strong>寻求最优解法</strong>：同一个问题可能存在多种解法，我们希望找到尽可能高效的算法。</li>
</ol>
<p>因此在能够解决问题的前提下，算法效率成为主要的评价维度，包括：</p>
<p>因此，在能够解决问题的前提下，算法效率已成为衡量算法优劣的主要评价指标，它包括以下两个维度。</p>
<ul>
<li><strong>时间效率</strong>：算法运行速度的快慢。</li>
<li><strong>空间效率</strong>：算法占用内存空间的大小。</li>
@@ -3440,22 +3440,22 @@
<p>效率评估方法主要分为两种：实际测试和理论估算。</p>
<h2 id="211">2.1.1 &nbsp; 实际测试<a class="headerlink" href="#211" title="Permanent link">&para;</a></h2>
<p>假设我们现在有算法 <code>A</code> 和算法 <code>B</code> ，它们都能解决同一问题，现在需要对比这两个算法的效率。最直接的方法是找一台计算机，运行这两个算法，并监控记录它们的运行时间和内存占用情况。这种评估方式能够反映真实情况，但也存在较大局限性。</p>
<p><strong>难以排除测试环境的干扰因素</strong>。硬件配置会影响算法的性能表现。比如在某台计算机中，算法 <code>A</code> 的运行时间比算法 <code>B</code> 短；但在另一台配置不同的计算机中，我们可能得到相反的测试结果。这意味着我们需要在各种机器上进行测试，统计平均效率，而这是不现实的。</p>
<p><strong>展开完整测试非常耗费资源</strong>。随着输入数据量的变化，算法会表现出不同的效率。例如，在输入数据量较小时，算法 <code>A</code> 的运行时间比算法 <code>B</code> 更少；而输入数据量较大时，测试结果可能恰恰相反。因此，为了得到有说服力的结论，我们需要测试各种规模的输入数据，而这样需要耗费大量的计算资源。</p>
<p>一方面，<strong>难以排除测试环境的干扰因素</strong>。硬件配置会影响算法的性能表现。比如在某台计算机中，算法 <code>A</code> 的运行时间比算法 <code>B</code> 短；但在另一台配置不同的计算机中，我们可能得到相反的测试结果。这意味着我们需要在各种机器上进行测试，统计平均效率，而这是不现实的。</p>
<p>另一方面，<strong>展开完整测试非常耗费资源</strong>。随着输入数据量的变化，算法会表现出不同的效率。例如，在输入数据量较小时，算法 <code>A</code> 的运行时间比算法 <code>B</code> 更少；而输入数据量较大时，测试结果可能恰恰相反。因此，为了得到有说服力的结论，我们需要测试各种规模的输入数据，而这样需要耗费大量的计算资源。</p>
<h2 id="212">2.1.2 &nbsp; 理论估算<a class="headerlink" href="#212" title="Permanent link">&para;</a></h2>
<p>由于实际测试具有较大的局限性，我们可以考虑仅通过一些计算来评估算法的效率。这种估算方法被称为「渐近复杂度分析 Asymptotic Complexity Analysis」，简称为「复杂度分析」。</p>
<p>复杂度分析评估的是算法执行所需的时间和空间资源。<strong>它被表示为一个函数，描述了随着输入数据大小的增加，算法所需时间（空间）的增长趋势</strong>。这个定义有些拗口，我们可以将其分为三个重点来理解：</p>
<p>由于实际测试具有较大的局限性，我们可以考虑仅通过一些计算来评估算法的效率。这种估算方法被称为「渐近复杂度分析 asymptotic complexity analysis」，简称「复杂度分析」。</p>
<p>复杂度分析评估的是算法运行所需的时间和空间资源，<strong>它描述了随着输入数据大小的增加，算法所需时间（空间）的增长趋势</strong>。这个定义有些拗口，我们可以将其分为三个重点来理解。</p>
<ol>
<li>“时间（空间）”分别对应「时间复杂度 Time Complexity」和「空间复杂度 Space Complexity」。</li>
<li>“时间和空间资源”分别对应「时间复杂度 time complexity」和「空间复杂度 space complexity」。</li>
<li>“随着输入数据大小的增加”意味着复杂度反映了算法运行效率与输入数据体量之间的关系。</li>
<li>“增长趋势”表示复杂度分析关注的是算法时间与空间的增长趋势，而非具体的运行时间或占用空间。</li>
</ol>
<p><strong>复杂度分析克服了实际测试方法的弊端</strong>。首先，它独立于测试环境，分析结果适用于所有运行平台。其次，它可以体现不同数据量下的算法效率，尤其是在大数据量下的算法性能。</p>
<p>如果你对复杂度分析的概念仍感到困惑，无需担心，我们会在后续章节详细介绍。</p>
<p>如果你对复杂度分析的概念仍感到困惑，无须担心，我们会在后续章节中详细介绍。</p>
<h2 id="213">2.1.3 &nbsp; 复杂度的重要性<a class="headerlink" href="#213" title="Permanent link">&para;</a></h2>
<p>复杂度分析为我们提供了一把评估算法效率的“标尺”，帮助我们衡量了执行某个算法所需的时间和空间资源，并使我们能够对比不同算法之间的效率。</p>
<p>复杂度是个数学概念，对于初学者可能比较抽象，学习难度相对较高。从这个角度看，复杂度分析可能不太适合作为第一章的内容。</p>
<p>然而，当我们讨论某个数据结构或算法的特点时，难以避免要分析其运行速度和空间使用情况。因此，在深入学习数据结构与算法之前，<strong>建议你先对复杂度建立初步的了解，能够完成简单算法的复杂度分析</strong>。</p>
<p>复杂度是个数学概念，对于初学者可能比较抽象，学习难度相对较高。从这个角度看，复杂度分析可能不太适合作为第 1 章的内容。</p>
<p>然而，当我们讨论某个数据结构或算法的特点时，难以避免要分析其运行速度和空间使用情况。因此，在深入学习数据结构与算法之前，<strong>建议你先对复杂度建立初步的了解，以便能够完成简单算法的复杂度分析</strong>。</p>
chapter_computational_complexity/space_complexity/index.html
+19 -19
View File
@@ -3522,22 +3522,22 @@
<h1 id="23">2.3 &nbsp; 空间复杂度<a class="headerlink" href="#23" title="Permanent link">&para;</a></h1>
<p>「空间复杂度 Space Complexity」用于衡量算法占用内存空间随着数据量变大时的增长趋势。这个概念与时间复杂度非常类似，只需将“运行时间”替换为“占用内存空间”。</p>
<p>「空间复杂度 space complexity」用于衡量算法占用内存空间随着数据量变大时的增长趋势。这个概念与时间复杂度非常类似，只需将“运行时间”替换为“占用内存空间”。</p>
<h2 id="231">2.3.1 &nbsp; 算法相关空间<a class="headerlink" href="#231" title="Permanent link">&para;</a></h2>
<p>算法运行过程中使用的内存空间主要包括以下几种：</p>
<p>算法在运行过程中使用的内存空间主要包括以下几种。</p>
<ul>
<li><strong>输入空间</strong>：用于存储算法的输入数据。</li>
<li><strong>暂存空间</strong>：用于存储算法运行过程中的变量、对象、函数上下文等数据。</li>
<li><strong>暂存空间</strong>：用于存储算法在运行过程中的变量、对象、函数上下文等数据。</li>
<li><strong>输出空间</strong>：用于存储算法的输出数据。</li>
</ul>
<p>一般情况下，空间复杂度的统计范围是“暂存空间”加上“输出空间”。</p>
<p>暂存空间可以进一步划分为三个部分：</p>
<p>暂存空间可以进一步划分为三个部分。</p>
<ul>
<li><strong>暂存数据</strong>：用于保存算法运行过程中的各种常量、变量、对象等。</li>
<li><strong>栈帧空间</strong>：用于保存调用函数的上下文数据。系统在每次调用函数时都会在栈顶部创建一个栈帧，函数返回后，栈帧空间会被释放。</li>
<li><strong>指令空间</strong>：用于保存编译后的程序指令，在实际统计中通常忽略不计。</li>
</ul>
<p>因此在分析一段程序的空间复杂度时，<strong>我们通常统计暂存数据、输出数据、栈帧空间三部分</strong>。</p>
<p>在分析一段程序的空间复杂度时，<strong>我们通常统计暂存数据、栈帧空间和输出数据三部分</strong>。</p>
<p><img alt="算法使用的相关空间" src="../space_complexity.assets/space_types.png" /></p>
<p align="center"> 图：算法使用的相关空间 </p>
@@ -3786,7 +3786,7 @@
</div>
</div>
<h2 id="232">2.3.2 &nbsp; 推算方法<a class="headerlink" href="#232" title="Permanent link">&para;</a></h2>
<p>空间复杂度的推算方法与时间复杂度大致相同，只需将统计对象从“计算操作数量”转为“使用空间大小”。</p>
<p>空间复杂度的推算方法与时间复杂度大致相同，只需将统计对象从“操作数量”转为“使用空间大小”。</p>
<p>而与时间复杂度不同的是，<strong>我们通常只关注「最差空间复杂度」</strong>。这是因为内存空间是一项硬性要求，我们必须确保在所有输入数据下都有足够的内存空间预留。</p>
<p>观察以下代码，最差空间复杂度中的“最差”有两层含义。</p>
<ol>
@@ -3902,7 +3902,7 @@
</div>
</div>
</div>
<p><strong>在递归函数中，需要注意统计栈帧空间</strong>。例如以下代码：</p>
<p><strong>在递归函数中，需要注意统计栈帧空间</strong>。例如在以下代码中：</p>
<ul>
<li>函数 <code>loop()</code> 在循环中调用了 <span class="arithmatex">\(n\)</span> 次 <code>function()</code> ，每轮中的 <code>function()</code> 都返回并释放了栈帧空间，因此空间复杂度仍为 <span class="arithmatex">\(O(1)\)</span> 。</li>
<li>递归函数 <code>recur()</code> 在运行过程中会同时存在 <span class="arithmatex">\(n\)</span> 个未返回的 <code>recur()</code> ，从而占用 <span class="arithmatex">\(O(n)\)</span> 的栈帧空间。</li>
@@ -4107,23 +4107,23 @@
</div>
</div>
<h2 id="233">2.3.3 &nbsp; 常见类型<a class="headerlink" href="#233" title="Permanent link">&para;</a></h2>
<p>设输入数据大小为 <span class="arithmatex">\(n\)</span> ，常见的空间复杂度类型有（从低到高排列）：</p>
<p>设输入数据大小为 <span class="arithmatex">\(n\)</span> ，下图展示了常见的空间复杂度类型（从低到高排列）。</p>
<div class="arithmatex">\[
\begin{aligned}
O(1) &lt; O(\log n) &lt; O(n) &lt; O(n^2) &lt; O(2^n) \newline
\text{常数阶} &lt; \text{对数阶} &lt; \text{线性阶} &lt; \text{平方阶} &lt; \text{指数阶}
\end{aligned}
\]</div>
<p><img alt="空间复杂度的常见类型" src="../space_complexity.assets/space_complexity_common_types.png" /></p>
<p align="center"> 图：空间复杂度的常见类型 </p>
<p><img alt="常见的空间复杂度类型" src="../space_complexity.assets/space_complexity_common_types.png" /></p>
<p align="center"> 图：常见的空间复杂度类型 </p>
<div class="admonition tip">
<p class="admonition-title">Tip</p>
<p>部分示例代码需要一些前置知识，包括数组、链表、二叉树、递归算法等。如果你遇到看不懂的地方，可以在学习完后面章节后再来复习。</p>
<p>部分示例代码需要一些前置知识，包括数组、链表、二叉树、递归算法等。如果你遇到看不懂的地方，可以在学完后面章节后再来复习。</p>
</div>
<h3 id="1-o1">1. &nbsp; 常数阶 <span class="arithmatex">\(O(1)\)</span><a class="headerlink" href="#1-o1" title="Permanent link">&para;</a></h3>
<p>常数阶常见于数量与输入数据大小 <span class="arithmatex">\(n\)</span> 无关的常量、变量、对象。</p>
<p>需要注意的是，在循环中初始化变量或调用函数而占用的内存，在进入下一循环后就会被释放，即不会累积占用空间，空间复杂度仍为 <span class="arithmatex">\(O(1)\)</span> 。</p>
<p>需要注意的是，在循环中初始化变量或调用函数而占用的内存，在进入下一循环后就会被释放，即不会累积占用空间，空间复杂度仍为 <span class="arithmatex">\(O(1)\)</span> ：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="4:12"><input checked="checked" id="__tabbed_4_1" name="__tabbed_4" type="radio" /><input id="__tabbed_4_2" name="__tabbed_4" type="radio" /><input id="__tabbed_4_3" name="__tabbed_4" type="radio" /><input id="__tabbed_4_4" name="__tabbed_4" type="radio" /><input id="__tabbed_4_5" name="__tabbed_4" type="radio" /><input id="__tabbed_4_6" name="__tabbed_4" type="radio" /><input id="__tabbed_4_7" name="__tabbed_4" type="radio" /><input id="__tabbed_4_8" name="__tabbed_4" type="radio" /><input id="__tabbed_4_9" name="__tabbed_4" type="radio" /><input id="__tabbed_4_10" name="__tabbed_4" type="radio" /><input id="__tabbed_4_11" name="__tabbed_4" type="radio" /><input id="__tabbed_4_12" name="__tabbed_4" type="radio" /><div class="tabbed-labels"><label for="__tabbed_4_1">Java</label><label for="__tabbed_4_2">C++</label><label for="__tabbed_4_3">Python</label><label for="__tabbed_4_4">Go</label><label for="__tabbed_4_5">JS</label><label for="__tabbed_4_6">TS</label><label for="__tabbed_4_7">C</label><label for="__tabbed_4_8">C#</label><label for="__tabbed_4_9">Swift</label><label for="__tabbed_4_10">Zig</label><label for="__tabbed_4_11">Dart</label><label for="__tabbed_4_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -4432,7 +4432,7 @@ O(1) &lt; O(\log n) &lt; O(n) &lt; O(n^2) &lt; O(2^n) \newline
</div>
</div>
<h3 id="2-on">2. &nbsp; 线性阶 <span class="arithmatex">\(O(n)\)</span><a class="headerlink" href="#2-on" title="Permanent link">&para;</a></h3>
<p>线性阶常见于元素数量与 <span class="arithmatex">\(n\)</span> 成正比的数组、链表、栈、队列等。</p>
<p>线性阶常见于元素数量与 <span class="arithmatex">\(n\)</span> 成正比的数组、链表、栈、队列等：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="5:12"><input checked="checked" id="__tabbed_5_1" name="__tabbed_5" type="radio" /><input id="__tabbed_5_2" name="__tabbed_5" type="radio" /><input id="__tabbed_5_3" name="__tabbed_5" type="radio" /><input id="__tabbed_5_4" name="__tabbed_5" type="radio" /><input id="__tabbed_5_5" name="__tabbed_5" type="radio" /><input id="__tabbed_5_6" name="__tabbed_5" type="radio" /><input id="__tabbed_5_7" name="__tabbed_5" type="radio" /><input id="__tabbed_5_8" name="__tabbed_5" type="radio" /><input id="__tabbed_5_9" name="__tabbed_5" type="radio" /><input id="__tabbed_5_10" name="__tabbed_5" type="radio" /><input id="__tabbed_5_11" name="__tabbed_5" type="radio" /><input id="__tabbed_5_12" name="__tabbed_5" type="radio" /><div class="tabbed-labels"><label for="__tabbed_5_1">Java</label><label for="__tabbed_5_2">C++</label><label for="__tabbed_5_3">Python</label><label for="__tabbed_5_4">Go</label><label for="__tabbed_5_5">JS</label><label for="__tabbed_5_6">TS</label><label for="__tabbed_5_7">C</label><label for="__tabbed_5_8">C#</label><label for="__tabbed_5_9">Swift</label><label for="__tabbed_5_10">Zig</label><label for="__tabbed_5_11">Dart</label><label for="__tabbed_5_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -4675,7 +4675,7 @@ O(1) &lt; O(\log n) &lt; O(n) &lt; O(n^2) &lt; O(2^n) \newline
</div>
</div>
</div>
<p>以下递归函数会同时存在 <span class="arithmatex">\(n\)</span> 个未返回的 <code>algorithm()</code> 函数，使用 <span class="arithmatex">\(O(n)\)</span> 大小的栈帧空间。</p>
<p>以下递归函数会同时存在 <span class="arithmatex">\(n\)</span> 个未返回的 <code>algorithm()</code> 函数，使用 <span class="arithmatex">\(O(n)\)</span> 大小的栈帧空间：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="6:12"><input checked="checked" id="__tabbed_6_1" name="__tabbed_6" type="radio" /><input id="__tabbed_6_2" name="__tabbed_6" type="radio" /><input id="__tabbed_6_3" name="__tabbed_6" type="radio" /><input id="__tabbed_6_4" name="__tabbed_6" type="radio" /><input id="__tabbed_6_5" name="__tabbed_6" type="radio" /><input id="__tabbed_6_6" name="__tabbed_6" type="radio" /><input id="__tabbed_6_7" name="__tabbed_6" type="radio" /><input id="__tabbed_6_8" name="__tabbed_6" type="radio" /><input id="__tabbed_6_9" name="__tabbed_6" type="radio" /><input id="__tabbed_6_10" name="__tabbed_6" type="radio" /><input id="__tabbed_6_11" name="__tabbed_6" type="radio" /><input id="__tabbed_6_12" name="__tabbed_6" type="radio" /><div class="tabbed-labels"><label for="__tabbed_6_1">Java</label><label for="__tabbed_6_2">C++</label><label for="__tabbed_6_3">Python</label><label for="__tabbed_6_4">Go</label><label for="__tabbed_6_5">JS</label><label for="__tabbed_6_6">TS</label><label for="__tabbed_6_7">C</label><label for="__tabbed_6_8">C#</label><label for="__tabbed_6_9">Swift</label><label for="__tabbed_6_10">Zig</label><label for="__tabbed_6_11">Dart</label><label for="__tabbed_6_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -4799,7 +4799,7 @@ O(1) &lt; O(\log n) &lt; O(n) &lt; O(n^2) &lt; O(2^n) \newline
<p align="center"> 图：递归函数产生的线性阶空间复杂度 </p>
<h3 id="3-on2">3. &nbsp; 平方阶 <span class="arithmatex">\(O(n^2)\)</span><a class="headerlink" href="#3-on2" title="Permanent link">&para;</a></h3>
<p>平方阶常见于矩阵和图，元素数量与 <span class="arithmatex">\(n\)</span> 成平方关系。</p>
<p>平方阶常见于矩阵和图，元素数量与 <span class="arithmatex">\(n\)</span> 成平方关系：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="7:12"><input checked="checked" id="__tabbed_7_1" name="__tabbed_7" type="radio" /><input id="__tabbed_7_2" name="__tabbed_7" type="radio" /><input id="__tabbed_7_3" name="__tabbed_7" type="radio" /><input id="__tabbed_7_4" name="__tabbed_7" type="radio" /><input id="__tabbed_7_5" name="__tabbed_7" type="radio" /><input id="__tabbed_7_6" name="__tabbed_7" type="radio" /><input id="__tabbed_7_7" name="__tabbed_7" type="radio" /><input id="__tabbed_7_8" name="__tabbed_7" type="radio" /><input id="__tabbed_7_9" name="__tabbed_7" type="radio" /><input id="__tabbed_7_10" name="__tabbed_7" type="radio" /><input id="__tabbed_7_11" name="__tabbed_7" type="radio" /><input id="__tabbed_7_12" name="__tabbed_7" type="radio" /><div class="tabbed-labels"><label for="__tabbed_7_1">Java</label><label for="__tabbed_7_2">C++</label><label for="__tabbed_7_3">Python</label><label for="__tabbed_7_4">Go</label><label for="__tabbed_7_5">JS</label><label for="__tabbed_7_6">TS</label><label for="__tabbed_7_7">C</label><label for="__tabbed_7_8">C#</label><label for="__tabbed_7_9">Swift</label><label for="__tabbed_7_10">Zig</label><label for="__tabbed_7_11">Dart</label><label for="__tabbed_7_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -5134,7 +5134,7 @@ O(1) &lt; O(\log n) &lt; O(n) &lt; O(n^2) &lt; O(2^n) \newline
<p align="center"> 图：递归函数产生的平方阶空间复杂度 </p>
<h3 id="4-o2n">4. &nbsp; 指数阶 <span class="arithmatex">\(O(2^n)\)</span><a class="headerlink" href="#4-o2n" title="Permanent link">&para;</a></h3>
<p>指数阶常见于二叉树。高度为 <span class="arithmatex">\(n\)</span> 的「满二叉树」的节点数量为 <span class="arithmatex">\(2^n - 1\)</span> ，占用 <span class="arithmatex">\(O(2^n)\)</span> 空间。</p>
<p>指数阶常见于二叉树。高度为 <span class="arithmatex">\(n\)</span> 的「满二叉树」的节点数量为 <span class="arithmatex">\(2^n - 1\)</span> ，占用 <span class="arithmatex">\(O(2^n)\)</span> 空间：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="9:12"><input checked="checked" id="__tabbed_9_1" name="__tabbed_9" type="radio" /><input id="__tabbed_9_2" name="__tabbed_9" type="radio" /><input id="__tabbed_9_3" name="__tabbed_9" type="radio" /><input id="__tabbed_9_4" name="__tabbed_9" type="radio" /><input id="__tabbed_9_5" name="__tabbed_9" type="radio" /><input id="__tabbed_9_6" name="__tabbed_9" type="radio" /><input id="__tabbed_9_7" name="__tabbed_9" type="radio" /><input id="__tabbed_9_8" name="__tabbed_9" type="radio" /><input id="__tabbed_9_9" name="__tabbed_9" type="radio" /><input id="__tabbed_9_10" name="__tabbed_9" type="radio" /><input id="__tabbed_9_11" name="__tabbed_9" type="radio" /><input id="__tabbed_9_12" name="__tabbed_9" type="radio" /><div class="tabbed-labels"><label for="__tabbed_9_1">Java</label><label for="__tabbed_9_2">C++</label><label for="__tabbed_9_3">Python</label><label for="__tabbed_9_4">Go</label><label for="__tabbed_9_5">JS</label><label for="__tabbed_9_6">TS</label><label for="__tabbed_9_7">C</label><label for="__tabbed_9_8">C#</label><label for="__tabbed_9_9">Swift</label><label for="__tabbed_9_10">Zig</label><label for="__tabbed_9_11">Dart</label><label for="__tabbed_9_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -5284,12 +5284,12 @@ O(1) &lt; O(\log n) &lt; O(n) &lt; O(n^2) &lt; O(2^n) \newline
<h3 id="5-olog-n">5. &nbsp; 对数阶 <span class="arithmatex">\(O(\log n)\)</span><a class="headerlink" href="#5-olog-n" title="Permanent link">&para;</a></h3>
<p>对数阶常见于分治算法和数据类型转换等。</p>
<p>例如“归并排序”算法，输入长度为 <span class="arithmatex">\(n\)</span> 的数组，每轮递归将数组从中点划分为两半，形成高度为 <span class="arithmatex">\(\log n\)</span> 的递归树，使用 <span class="arithmatex">\(O(\log n)\)</span> 栈帧空间。</p>
<p>再例如“数字转化为字符串”，输入任意正整数 <span class="arithmatex">\(n\)</span> ，它的位数为 <span class="arithmatex">\(\log_{10} n\)</span> ，即对应字符串长度为 <span class="arithmatex">\(\log_{10} n\)</span> ，因此空间复杂度为 <span class="arithmatex">\(O(\log_{10} n) = O(\log n)\)</span> 。</p>
<p>例如归并排序算法，输入长度为 <span class="arithmatex">\(n\)</span> 的数组，每轮递归将数组从中点划分为两半，形成高度为 <span class="arithmatex">\(\log n\)</span> 的递归树，使用 <span class="arithmatex">\(O(\log n)\)</span> 栈帧空间。</p>
<p>再例如将数字转化为字符串，输入任意正整数 <span class="arithmatex">\(n\)</span> ，它的位数为 <span class="arithmatex">\(\log_{10} n + 1\)</span> ，即对应字符串长度为 <span class="arithmatex">\(\log_{10} n + 1\)</span> ，因此空间复杂度为 <span class="arithmatex">\(O(\log_{10} n + 1) = O(\log n)\)</span> 。</p>
<h2 id="234">2.3.4 &nbsp; 权衡时间与空间<a class="headerlink" href="#234" title="Permanent link">&para;</a></h2>
<p>理想情况下，我们希望算法的时间复杂度和空间复杂度都能达到最优。然而在实际情况中，同时优化时间复杂度和空间复杂度通常是非常困难的。</p>
<p><strong>降低时间复杂度通常需要以提升空间复杂度为代价，反之亦然</strong>。我们将牺牲内存空间来提升算法运行速度的思路称为“以空间换时间”；反之，则称为“以时间换空间”。</p>
<p>选择哪种思路取决于我们更看重哪个方面。在大多数情况下，时间比空间更宝贵，因此以空间换时间通常是更常用的策略。当然，在数据量很大的情况下，控制空间复杂度也是非常重要的。</p>
<p>选择哪种思路取决于我们更看重哪个方面。在大多数情况下，时间比空间更宝贵，因此“以空间换时间”通常是更常用的策略。当然，在数据量很大的情况下，控制空间复杂度也是非常重要的。</p>
chapter_computational_complexity/summary/index.html
+15 -15
View File
@@ -3400,44 +3400,44 @@
<h1 id="24">2.4 &nbsp; 小结<a class="headerlink" href="#24" title="Permanent link">&para;</a></h1>
<p><strong>算法效率评估</strong></p>
<ul>
<li>时间效率和空间效率是评价算法性能的两个关键维度。</li>
<li>时间效率和空间效率是衡量算法优劣的两个主要评价指标。</li>
<li>我们可以通过实际测试来评估算法效率，但难以消除测试环境的影响，且会耗费大量计算资源。</li>
<li>复杂度分析可以克服实际测试的弊端，分析结果适用于所有运行平台，并且能够揭示算法在不同数据规模下的效率。</li>
</ul>
<p><strong>时间复杂度</strong></p>
<ul>
<li>时间复杂度用于衡量算法运行时间随数据量增长的趋势，可以有效评估算法效率，但在某些情况下可能失效，如在输入数据量较小或时间复杂度相同时，无法精确对比算法效率的优劣。</li>
<li>最差时间复杂度使用大 <span class="arithmatex">\(O\)</span> 符号表示，即函数渐近上界，反映当 <span class="arithmatex">\(n\)</span> 趋向正无穷时，<span class="arithmatex">\(T(n)\)</span> 的增长级别。</li>
<li>推算时间复杂度分为两步，首先统计计算操作数量，然后判断渐近上界。</li>
<li>常见时间复杂度从小到大排列有 <span class="arithmatex">\(O(1)\)</span> , <span class="arithmatex">\(O(\log n)\)</span> , <span class="arithmatex">\(O(n)\)</span> , <span class="arithmatex">\(O(n \log n)\)</span> , <span class="arithmatex">\(O(n^2)\)</span> , <span class="arithmatex">\(O(2^n)\)</span> , <span class="arithmatex">\(O(n!)\)</span> 等。</li>
<li>时间复杂度用于衡量算法运行时间随数据量增长的趋势，可以有效评估算法效率，但在某些情况下可能失效，如在输入的数据量较小或时间复杂度相同时，无法精确对比算法效率的优劣。</li>
<li>最差时间复杂度使用大 <span class="arithmatex">\(O\)</span> 符号表示，对应函数渐近上界，反映当 <span class="arithmatex">\(n\)</span> 趋向正无穷时，操作数量 <span class="arithmatex">\(T(n)\)</span> 的增长级别。</li>
<li>推算时间复杂度分为两步，首先统计操作数量，然后判断渐近上界。</li>
<li>常见时间复杂度从小到大排列有 <span class="arithmatex">\(O(1)\)</span> 、<span class="arithmatex">\(O(\log n)\)</span> 、<span class="arithmatex">\(O(n)\)</span> 、<span class="arithmatex">\(O(n \log n)\)</span> 、<span class="arithmatex">\(O(n^2)\)</span> 、<span class="arithmatex">\(O(2^n)\)</span> 、<span class="arithmatex">\(O(n!)\)</span> 等。</li>
<li>某些算法的时间复杂度非固定，而是与输入数据的分布有关。时间复杂度分为最差、最佳、平均时间复杂度，最佳时间复杂度几乎不用，因为输入数据一般需要满足严格条件才能达到最佳情况。</li>
<li>平均时间复杂度反映算法在随机数据输入下的运行效率，最接近实际应用中的算法性能。计算平均时间复杂度需要统计输入数据分布以及综合后的数学期望。</li>
</ul>
<p><strong>空间复杂度</strong></p>
<ul>
<li>类似于时间复杂度，空间复杂度用于衡量算法占用空间随数据量增长的趋势。</li>
<li>空间复杂度的作用类似于时间复杂度，用于衡量算法占用空间随数据量增长的趋势。</li>
<li>算法运行过程中的相关内存空间可分为输入空间、暂存空间、输出空间。通常情况下，输入空间不计入空间复杂度计算。暂存空间可分为指令空间、数据空间、栈帧空间，其中栈帧空间通常仅在递归函数中影响空间复杂度。</li>
<li>我们通常只关注最差空间复杂度，即统计算法在最差输入数据和最差运行时间点下的空间复杂度。</li>
<li>常见空间复杂度从小到大排列有 <span class="arithmatex">\(O(1)\)</span> , <span class="arithmatex">\(O(\log n)\)</span> , <span class="arithmatex">\(O(n)\)</span> , <span class="arithmatex">\(O(n^2)\)</span> , <span class="arithmatex">\(O(2^n)\)</span> 等。</li>
<li>常见空间复杂度从小到大排列有 <span class="arithmatex">\(O(1)\)</span> 、<span class="arithmatex">\(O(\log n)\)</span> 、<span class="arithmatex">\(O(n)\)</span> 、<span class="arithmatex">\(O(n^2)\)</span> 、<span class="arithmatex">\(O(2^n)\)</span> 等。</li>
</ul>
<h2 id="241-q-a">2.4.1 &nbsp; Q &amp; A<a class="headerlink" href="#241-q-a" title="Permanent link">&para;</a></h2>
<div class="admonition question">
<p class="admonition-title">尾递归的空间复杂度是 <span class="arithmatex">\(O(1)\)</span> 吗？</p>
<p>理论上，尾递归函数的空间复杂度可以被优化至 <span class="arithmatex">\(O(1)\)</span> 。不过绝大多数编程语言（例如 Java, Python, C++, Go, C# 等）都不支持自动优化尾递归，因此通常认为空间复杂度是 <span class="arithmatex">\(O(n)\)</span> 。</p>
<p>理论上，尾递归函数的空间复杂度可以被优化至 <span class="arithmatex">\(O(1)\)</span> 。不过绝大多数编程语言（例如 Java 、Python 、C++ 、Go 、C# 等）都不支持自动优化尾递归，因此通常认为空间复杂度是 <span class="arithmatex">\(O(n)\)</span> 。</p>
</div>
<div class="admonition question">
<p class="admonition-title">函数和方法这两个术语的区别是什么？</p>
<p>函数（function）可以独立被执行，所有参数都以显式传递。方法（method）与一个对象关联，方法被隐式传递给调用它的对象，方法能够对类的实例中包含的数据进行操作。</p>
<p>以几个常见的编程语言为例：</p>
<p>函数（function）可以被独立执行，所有参数都以显式传递。方法（method）与一个对象关联，被隐式传递给调用它的对象，能够对类的实例中包含的数据进行操作。</p>
<p>下面以几个常见的编程语言来说明。</p>
<ul>
<li>C 语言是过程式编程语言，没有面向对象的概念，所以只有函数。但我们可以通过创建结构（struct）来模拟面向对象编程，与结构体相关联的函数就相当于其他语言中的方法。</li>
<li>Java, C# 是面向对象的编程语言，代码块（方法）通常都是作为某个类的一部分。静态方法的行为类似于函数，因为它被绑定在类上，不能访问特定的实例变量。</li>
<li>C++, Python 既支持过程式编程（函数）也支持面向对象编程（方法）。</li>
<li>C 语言是过程式编程语言，没有面向对象的概念，所以只有函数。但我们可以通过创建结构体（struct）来模拟面向对象编程，与结构体相关联的函数就相当于其他语言中的方法。</li>
<li>Java 和 C# 是面向对象的编程语言，代码块（方法）通常都是作为某个类的一部分。静态方法的行为类似于函数，因为它被绑定在类上，不能访问特定的实例变量。</li>
<li>C++ 和 Python 既支持过程式编程（函数），也支持面向对象编程（方法）。</li>
</ul>
</div>
<div class="admonition question">
<p class="admonition-title">图片“空间复杂度的常见类型”反映的是否是占用空间的绝对大小？</p>
<p>不是，该图片展示的是空间复杂度，其反映的是即增长趋势，而不是占用空间的绝对大小。</p>
<p class="admonition-title">图“空间复杂度的常见类型”反映的是否是占用空间的绝对大小？</p>
<p>不是，该图片展示的是空间复杂度，其反映的是增长趋势，而不是占用空间的绝对大小。</p>
<p>假设取 <span class="arithmatex">\(n = 8\)</span> ，你可能会发现每条曲线的值与函数对应不上。这是因为每条曲线都包含一个常数项，用于将取值范围压缩到一个视觉舒适的范围内。</p>
<p>在实际中，因为我们通常不知道每个方法的“常数项”复杂度是多少，所以一般无法仅凭复杂度来选择 <span class="arithmatex">\(n = 8\)</span> 之下的最优解法。但对于 <span class="arithmatex">\(n = 8^5\)</span> 就很好选了，这时增长趋势已经占主导了。</p>
</div>
chapter_computational_complexity/time_complexity/index.html
+84 -80
View File
@@ -3607,13 +3607,10 @@
<p>运行时间可以直观且准确地反映算法的效率。如果我们想要准确预估一段代码的运行时间，应该如何操作呢？</p>
<ol>
<li><strong>确定运行平台</strong>，包括硬件配置、编程语言、系统环境等，这些因素都会影响代码的运行效率。</li>
<li><strong>评估各种计算操作所需的运行时间</strong>，例如加法操作 <code>+</code> 需要 1 ns，乘法操作 <code>*</code> 需要 10 ns，打印操作需要 5 ns 等。</li>
<li><strong>评估各种计算操作所需的运行时间</strong>，例如加法操作 <code>+</code> 需要 1 ns，乘法操作 <code>*</code> 需要 10 ns，打印操作 <code>print()</code> 需要 5 ns 等。</li>
<li><strong>统计代码中所有的计算操作</strong>，并将所有操作的执行时间求和，从而得到运行时间。</li>
</ol>
<p>例如以下代码，输入数据大小为 <span class="arithmatex">\(n\)</span> 。根据以上方法，可以得到算法运行时间为 <span class="arithmatex">\(6n + 12\)</span> ns 。</p>
<div class="arithmatex">\[
1 + 1 + 10 + (1 + 5) \times n = 6n + 12
\]</div>
<p>例如在以下代码中，输入数据大小为 <span class="arithmatex">\(n\)</span> ：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="1:12"><input checked="checked" id="__tabbed_1_1" name="__tabbed_1" type="radio" /><input id="__tabbed_1_2" name="__tabbed_1" type="radio" /><input id="__tabbed_1_3" name="__tabbed_1" type="radio" /><input id="__tabbed_1_4" name="__tabbed_1" type="radio" /><input id="__tabbed_1_5" name="__tabbed_1" type="radio" /><input id="__tabbed_1_6" name="__tabbed_1" type="radio" /><input id="__tabbed_1_7" name="__tabbed_1" type="radio" /><input id="__tabbed_1_8" name="__tabbed_1" type="radio" /><input id="__tabbed_1_9" name="__tabbed_1" type="radio" /><input id="__tabbed_1_10" name="__tabbed_1" type="radio" /><input id="__tabbed_1_11" name="__tabbed_1" type="radio" /><input id="__tabbed_1_12" name="__tabbed_1" type="radio" /><div class="tabbed-labels"><label for="__tabbed_1_1">Java</label><label for="__tabbed_1_2">C++</label><label for="__tabbed_1_3">Python</label><label for="__tabbed_1_4">Go</label><label for="__tabbed_1_5">JS</label><label for="__tabbed_1_6">TS</label><label for="__tabbed_1_7">C</label><label for="__tabbed_1_8">C#</label><label for="__tabbed_1_9">Swift</label><label for="__tabbed_1_10">Zig</label><label for="__tabbed_1_11">Dart</label><label for="__tabbed_1_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -3763,24 +3760,28 @@
</div>
</div>
</div>
<p>但实际上，<strong>统计算法的运行时间既不合理也不现实</strong>。首先，我们不希望预估时间和运行平台绑定，因为算法需要在各种不同的平台上运行。其次，我们很难获知每种操作的运行时间，这给预估过程带来了极大的难度。</p>
<p>根据以上方法，可以得到算法运行时间为 <span class="arithmatex">\(6n + 12\)</span> ns ：</p>
<div class="arithmatex">\[
1 + 1 + 10 + (1 + 5) \times n = 6n + 12
\]</div>
<p>但实际上，<strong>统计算法的运行时间既不合理也不现实</strong>。首先，我们不希望将预估时间和运行平台绑定，因为算法需要在各种不同的平台上运行。其次，我们很难获知每种操作的运行时间，这给预估过程带来了极大的难度。</p>
<h2 id="221">2.2.1 &nbsp; 统计时间增长趋势<a class="headerlink" href="#221" title="Permanent link">&para;</a></h2>
<p>「时间复杂度分析」采取了一种不同的方法，其统计的不是算法运行时间，<strong>而是算法运行时间随着数据量变大时的增长趋势</strong>。</p>
<p>“时间增长趋势”这个概念比较抽象，我们通过一个例子来加以理解。假设输入数据大小为 <span class="arithmatex">\(n\)</span> ，给定三个算法函数 <code>A</code> , <code>B</code> , <code>C</code> 。</p>
<p>“时间增长趋势”这个概念比较抽象，我们通过一个例子来加以理解。假设输入数据大小为 <span class="arithmatex">\(n\)</span> ，给定三个算法函数 <code>A</code> 、 <code>B</code> 和 <code>C</code> ：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="2:12"><input checked="checked" id="__tabbed_2_1" name="__tabbed_2" type="radio" /><input id="__tabbed_2_2" name="__tabbed_2" type="radio" /><input id="__tabbed_2_3" name="__tabbed_2" type="radio" /><input id="__tabbed_2_4" name="__tabbed_2" type="radio" /><input id="__tabbed_2_5" name="__tabbed_2" type="radio" /><input id="__tabbed_2_6" name="__tabbed_2" type="radio" /><input id="__tabbed_2_7" name="__tabbed_2" type="radio" /><input id="__tabbed_2_8" name="__tabbed_2" type="radio" /><input id="__tabbed_2_9" name="__tabbed_2" type="radio" /><input id="__tabbed_2_10" name="__tabbed_2" type="radio" /><input id="__tabbed_2_11" name="__tabbed_2" type="radio" /><input id="__tabbed_2_12" name="__tabbed_2" type="radio" /><div class="tabbed-labels"><label for="__tabbed_2_1">Java</label><label for="__tabbed_2_2">C++</label><label for="__tabbed_2_3">Python</label><label for="__tabbed_2_4">Go</label><label for="__tabbed_2_5">JS</label><label for="__tabbed_2_6">TS</label><label for="__tabbed_2_7">C</label><label for="__tabbed_2_8">C#</label><label for="__tabbed_2_9">Swift</label><label for="__tabbed_2_10">Zig</label><label for="__tabbed_2_11">Dart</label><label for="__tabbed_2_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<div class="highlight"><pre><span></span><code><a id="__codelineno-12-1" name="__codelineno-12-1" href="#__codelineno-12-1"></a><span class="c1">// 算法 A 时间复杂度：常数阶</span>
<div class="highlight"><pre><span></span><code><a id="__codelineno-12-1" name="__codelineno-12-1" href="#__codelineno-12-1"></a><span class="c1">// 算法 A 的时间复杂度：常数阶</span>
<a id="__codelineno-12-2" name="__codelineno-12-2" href="#__codelineno-12-2"></a><span class="kt">void</span><span class="w"> </span><span class="nf">algorithm_A</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-12-3" name="__codelineno-12-3" href="#__codelineno-12-3"></a><span class="w"> </span><span class="n">System</span><span class="p">.</span><span class="na">out</span><span class="p">.</span><span class="na">println</span><span class="p">(</span><span class="mi">0</span><span class="p">);</span>
<a id="__codelineno-12-4" name="__codelineno-12-4" href="#__codelineno-12-4"></a><span class="p">}</span>
<a id="__codelineno-12-5" name="__codelineno-12-5" href="#__codelineno-12-5"></a><span class="c1">// 算法 B 时间复杂度：线性阶</span>
<a id="__codelineno-12-5" name="__codelineno-12-5" href="#__codelineno-12-5"></a><span class="c1">// 算法 B 的时间复杂度：线性阶</span>
<a id="__codelineno-12-6" name="__codelineno-12-6" href="#__codelineno-12-6"></a><span class="kt">void</span><span class="w"> </span><span class="nf">algorithm_B</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-12-7" name="__codelineno-12-7" href="#__codelineno-12-7"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">n</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-12-8" name="__codelineno-12-8" href="#__codelineno-12-8"></a><span class="w"> </span><span class="n">System</span><span class="p">.</span><span class="na">out</span><span class="p">.</span><span class="na">println</span><span class="p">(</span><span class="mi">0</span><span class="p">);</span>
<a id="__codelineno-12-9" name="__codelineno-12-9" href="#__codelineno-12-9"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-12-10" name="__codelineno-12-10" href="#__codelineno-12-10"></a><span class="p">}</span>
<a id="__codelineno-12-11" name="__codelineno-12-11" href="#__codelineno-12-11"></a><span class="c1">// 算法 C 时间复杂度：常数阶</span>
<a id="__codelineno-12-11" name="__codelineno-12-11" href="#__codelineno-12-11"></a><span class="c1">// 算法 C 的时间复杂度：常数阶</span>
<a id="__codelineno-12-12" name="__codelineno-12-12" href="#__codelineno-12-12"></a><span class="kt">void</span><span class="w"> </span><span class="nf">algorithm_C</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-12-13" name="__codelineno-12-13" href="#__codelineno-12-13"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="mi">1000000</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-12-14" name="__codelineno-12-14" href="#__codelineno-12-14"></a><span class="w"> </span><span class="n">System</span><span class="p">.</span><span class="na">out</span><span class="p">.</span><span class="na">println</span><span class="p">(</span><span class="mi">0</span><span class="p">);</span>
@@ -3789,17 +3790,17 @@
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><pre><span></span><code><a id="__codelineno-13-1" name="__codelineno-13-1" href="#__codelineno-13-1"></a><span class="c1">// 算法 A 时间复杂度：常数阶</span>
<div class="highlight"><pre><span></span><code><a id="__codelineno-13-1" name="__codelineno-13-1" href="#__codelineno-13-1"></a><span class="c1">// 算法 A 的时间复杂度：常数阶</span>
<a id="__codelineno-13-2" name="__codelineno-13-2" href="#__codelineno-13-2"></a><span class="kt">void</span><span class="w"> </span><span class="nf">algorithm_A</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-3" name="__codelineno-13-3" href="#__codelineno-13-3"></a><span class="w"> </span><span class="n">cout</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="n">endl</span><span class="p">;</span>
<a id="__codelineno-13-4" name="__codelineno-13-4" href="#__codelineno-13-4"></a><span class="p">}</span>
<a id="__codelineno-13-5" name="__codelineno-13-5" href="#__codelineno-13-5"></a><span class="c1">// 算法 B 时间复杂度：线性阶</span>
<a id="__codelineno-13-5" name="__codelineno-13-5" href="#__codelineno-13-5"></a><span class="c1">// 算法 B 的时间复杂度：线性阶</span>
<a id="__codelineno-13-6" name="__codelineno-13-6" href="#__codelineno-13-6"></a><span class="kt">void</span><span class="w"> </span><span class="nf">algorithm_B</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-7" name="__codelineno-13-7" href="#__codelineno-13-7"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">n</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-8" name="__codelineno-13-8" href="#__codelineno-13-8"></a><span class="w"> </span><span class="n">cout</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="n">endl</span><span class="p">;</span>
<a id="__codelineno-13-9" name="__codelineno-13-9" href="#__codelineno-13-9"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-10" name="__codelineno-13-10" href="#__codelineno-13-10"></a><span class="p">}</span>
<a id="__codelineno-13-11" name="__codelineno-13-11" href="#__codelineno-13-11"></a><span class="c1">// 算法 C 时间复杂度：常数阶</span>
<a id="__codelineno-13-11" name="__codelineno-13-11" href="#__codelineno-13-11"></a><span class="c1">// 算法 C 的时间复杂度：常数阶</span>
<a id="__codelineno-13-12" name="__codelineno-13-12" href="#__codelineno-13-12"></a><span class="kt">void</span><span class="w"> </span><span class="nf">algorithm_C</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-13" name="__codelineno-13-13" href="#__codelineno-13-13"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="mi">1000000</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-14" name="__codelineno-13-14" href="#__codelineno-13-14"></a><span class="w"> </span><span class="n">cout</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="n">endl</span><span class="p">;</span>
@@ -3808,31 +3809,31 @@
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><pre><span></span><code><a id="__codelineno-14-1" name="__codelineno-14-1" href="#__codelineno-14-1"></a><span class="c1"># 算法 A 时间复杂度：常数阶</span>
<div class="highlight"><pre><span></span><code><a id="__codelineno-14-1" name="__codelineno-14-1" href="#__codelineno-14-1"></a><span class="c1"># 算法 A 的时间复杂度：常数阶</span>
<a id="__codelineno-14-2" name="__codelineno-14-2" href="#__codelineno-14-2"></a><span class="k">def</span> <span class="nf">algorithm_A</span><span class="p">(</span><span class="n">n</span><span class="p">:</span> <span class="nb">int</span><span class="p">):</span>
<a id="__codelineno-14-3" name="__codelineno-14-3" href="#__codelineno-14-3"></a> <span class="nb">print</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>
<a id="__codelineno-14-4" name="__codelineno-14-4" href="#__codelineno-14-4"></a><span class="c1"># 算法 B 时间复杂度：线性阶</span>
<a id="__codelineno-14-4" name="__codelineno-14-4" href="#__codelineno-14-4"></a><span class="c1"># 算法 B 的时间复杂度：线性阶</span>
<a id="__codelineno-14-5" name="__codelineno-14-5" href="#__codelineno-14-5"></a><span class="k">def</span> <span class="nf">algorithm_B</span><span class="p">(</span><span class="n">n</span><span class="p">:</span> <span class="nb">int</span><span class="p">):</span>
<a id="__codelineno-14-6" name="__codelineno-14-6" href="#__codelineno-14-6"></a> <span class="k">for</span> <span class="n">_</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="n">n</span><span class="p">):</span>
<a id="__codelineno-14-7" name="__codelineno-14-7" href="#__codelineno-14-7"></a> <span class="nb">print</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>
<a id="__codelineno-14-8" name="__codelineno-14-8" href="#__codelineno-14-8"></a><span class="c1"># 算法 C 时间复杂度：常数阶</span>
<a id="__codelineno-14-8" name="__codelineno-14-8" href="#__codelineno-14-8"></a><span class="c1"># 算法 C 的时间复杂度：常数阶</span>
<a id="__codelineno-14-9" name="__codelineno-14-9" href="#__codelineno-14-9"></a><span class="k">def</span> <span class="nf">algorithm_C</span><span class="p">(</span><span class="n">n</span><span class="p">:</span> <span class="nb">int</span><span class="p">):</span>
<a id="__codelineno-14-10" name="__codelineno-14-10" href="#__codelineno-14-10"></a> <span class="k">for</span> <span class="n">_</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="mi">1000000</span><span class="p">):</span>
<a id="__codelineno-14-11" name="__codelineno-14-11" href="#__codelineno-14-11"></a> <span class="nb">print</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><pre><span></span><code><a id="__codelineno-15-1" name="__codelineno-15-1" href="#__codelineno-15-1"></a><span class="c1">// 算法 A 时间复杂度：常数阶</span>
<div class="highlight"><pre><span></span><code><a id="__codelineno-15-1" name="__codelineno-15-1" href="#__codelineno-15-1"></a><span class="c1">// 算法 A 的时间复杂度：常数阶</span>
<a id="__codelineno-15-2" name="__codelineno-15-2" href="#__codelineno-15-2"></a><span class="kd">func</span><span class="w"> </span><span class="nx">algorithm_A</span><span class="p">(</span><span class="nx">n</span><span class="w"> </span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-3" name="__codelineno-15-3" href="#__codelineno-15-3"></a><span class="w"> </span><span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>
<a id="__codelineno-15-4" name="__codelineno-15-4" href="#__codelineno-15-4"></a><span class="p">}</span>
<a id="__codelineno-15-5" name="__codelineno-15-5" href="#__codelineno-15-5"></a><span class="c1">// 算法 B 时间复杂度：线性阶</span>
<a id="__codelineno-15-5" name="__codelineno-15-5" href="#__codelineno-15-5"></a><span class="c1">// 算法 B 的时间复杂度：线性阶</span>
<a id="__codelineno-15-6" name="__codelineno-15-6" href="#__codelineno-15-6"></a><span class="kd">func</span><span class="w"> </span><span class="nx">algorithm_B</span><span class="p">(</span><span class="nx">n</span><span class="w"> </span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-7" name="__codelineno-15-7" href="#__codelineno-15-7"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="p">&lt;</span><span class="w"> </span><span class="nx">n</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-8" name="__codelineno-15-8" href="#__codelineno-15-8"></a><span class="w"> </span><span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>
<a id="__codelineno-15-9" name="__codelineno-15-9" href="#__codelineno-15-9"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-10" name="__codelineno-15-10" href="#__codelineno-15-10"></a><span class="p">}</span>
<a id="__codelineno-15-11" name="__codelineno-15-11" href="#__codelineno-15-11"></a><span class="c1">// 算法 C 时间复杂度：常数阶</span>
<a id="__codelineno-15-11" name="__codelineno-15-11" href="#__codelineno-15-11"></a><span class="c1">// 算法 C 的时间复杂度：常数阶</span>
<a id="__codelineno-15-12" name="__codelineno-15-12" href="#__codelineno-15-12"></a><span class="kd">func</span><span class="w"> </span><span class="nx">algorithm_C</span><span class="p">(</span><span class="nx">n</span><span class="w"> </span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-13" name="__codelineno-15-13" href="#__codelineno-15-13"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="p">&lt;</span><span class="w"> </span><span class="mi">1000000</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-14" name="__codelineno-15-14" href="#__codelineno-15-14"></a><span class="w"> </span><span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>
@@ -3841,17 +3842,17 @@
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><pre><span></span><code><a id="__codelineno-16-1" name="__codelineno-16-1" href="#__codelineno-16-1"></a><span class="c1">// 算法 A 时间复杂度：常数阶</span>
<div class="highlight"><pre><span></span><code><a id="__codelineno-16-1" name="__codelineno-16-1" href="#__codelineno-16-1"></a><span class="c1">// 算法 A 的时间复杂度：常数阶</span>
<a id="__codelineno-16-2" name="__codelineno-16-2" href="#__codelineno-16-2"></a><span class="kd">function</span><span class="w"> </span><span class="nx">algorithm_A</span><span class="p">(</span><span class="nx">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-3" name="__codelineno-16-3" href="#__codelineno-16-3"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="mf">0</span><span class="p">);</span>
<a id="__codelineno-16-4" name="__codelineno-16-4" href="#__codelineno-16-4"></a><span class="p">}</span>
<a id="__codelineno-16-5" name="__codelineno-16-5" href="#__codelineno-16-5"></a><span class="c1">// 算法 B 时间复杂度：线性阶</span>
<a id="__codelineno-16-5" name="__codelineno-16-5" href="#__codelineno-16-5"></a><span class="c1">// 算法 B 的时间复杂度：线性阶</span>
<a id="__codelineno-16-6" name="__codelineno-16-6" href="#__codelineno-16-6"></a><span class="kd">function</span><span class="w"> </span><span class="nx">algorithm_B</span><span class="p">(</span><span class="nx">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-7" name="__codelineno-16-7" href="#__codelineno-16-7"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">n</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-8" name="__codelineno-16-8" href="#__codelineno-16-8"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="mf">0</span><span class="p">);</span>
<a id="__codelineno-16-9" name="__codelineno-16-9" href="#__codelineno-16-9"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-16-10" name="__codelineno-16-10" href="#__codelineno-16-10"></a><span class="p">}</span>
<a id="__codelineno-16-11" name="__codelineno-16-11" href="#__codelineno-16-11"></a><span class="c1">// 算法 C 时间复杂度：常数阶</span>
<a id="__codelineno-16-11" name="__codelineno-16-11" href="#__codelineno-16-11"></a><span class="c1">// 算法 C 的时间复杂度：常数阶</span>
<a id="__codelineno-16-12" name="__codelineno-16-12" href="#__codelineno-16-12"></a><span class="kd">function</span><span class="w"> </span><span class="nx">algorithm_C</span><span class="p">(</span><span class="nx">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-13" name="__codelineno-16-13" href="#__codelineno-16-13"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="mf">1000000</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-14" name="__codelineno-16-14" href="#__codelineno-16-14"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="mf">0</span><span class="p">);</span>
@@ -3860,17 +3861,17 @@
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><pre><span></span><code><a id="__codelineno-17-1" name="__codelineno-17-1" href="#__codelineno-17-1"></a><span class="c1">// 算法 A 时间复杂度：常数阶</span>
<div class="highlight"><pre><span></span><code><a id="__codelineno-17-1" name="__codelineno-17-1" href="#__codelineno-17-1"></a><span class="c1">// 算法 A 的时间复杂度：常数阶</span>
<a id="__codelineno-17-2" name="__codelineno-17-2" href="#__codelineno-17-2"></a><span class="kd">function</span><span class="w"> </span><span class="nx">algorithm_A</span><span class="p">(</span><span class="nx">n</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="o">:</span><span class="w"> </span><span class="ow">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-3" name="__codelineno-17-3" href="#__codelineno-17-3"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="mf">0</span><span class="p">);</span>
<a id="__codelineno-17-4" name="__codelineno-17-4" href="#__codelineno-17-4"></a><span class="p">}</span>
<a id="__codelineno-17-5" name="__codelineno-17-5" href="#__codelineno-17-5"></a><span class="c1">// 算法 B 时间复杂度：线性阶</span>
<a id="__codelineno-17-5" name="__codelineno-17-5" href="#__codelineno-17-5"></a><span class="c1">// 算法 B 的时间复杂度：线性阶</span>
<a id="__codelineno-17-6" name="__codelineno-17-6" href="#__codelineno-17-6"></a><span class="kd">function</span><span class="w"> </span><span class="nx">algorithm_B</span><span class="p">(</span><span class="nx">n</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="o">:</span><span class="w"> </span><span class="ow">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-7" name="__codelineno-17-7" href="#__codelineno-17-7"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">n</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-8" name="__codelineno-17-8" href="#__codelineno-17-8"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="mf">0</span><span class="p">);</span>
<a id="__codelineno-17-9" name="__codelineno-17-9" href="#__codelineno-17-9"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-10" name="__codelineno-17-10" href="#__codelineno-17-10"></a><span class="p">}</span>
<a id="__codelineno-17-11" name="__codelineno-17-11" href="#__codelineno-17-11"></a><span class="c1">// 算法 C 时间复杂度：常数阶</span>
<a id="__codelineno-17-11" name="__codelineno-17-11" href="#__codelineno-17-11"></a><span class="c1">// 算法 C 的时间复杂度：常数阶</span>
<a id="__codelineno-17-12" name="__codelineno-17-12" href="#__codelineno-17-12"></a><span class="kd">function</span><span class="w"> </span><span class="nx">algorithm_C</span><span class="p">(</span><span class="nx">n</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="o">:</span><span class="w"> </span><span class="ow">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-13" name="__codelineno-17-13" href="#__codelineno-17-13"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="mf">1000000</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-14" name="__codelineno-17-14" href="#__codelineno-17-14"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="mf">0</span><span class="p">);</span>
@@ -3879,17 +3880,17 @@
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><pre><span></span><code><a id="__codelineno-18-1" name="__codelineno-18-1" href="#__codelineno-18-1"></a><span class="c1">// 算法 A 时间复杂度：常数阶</span>
<div class="highlight"><pre><span></span><code><a id="__codelineno-18-1" name="__codelineno-18-1" href="#__codelineno-18-1"></a><span class="c1">// 算法 A 的时间复杂度：常数阶</span>
<a id="__codelineno-18-2" name="__codelineno-18-2" href="#__codelineno-18-2"></a><span class="kt">void</span><span class="w"> </span><span class="nf">algorithm_A</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-3" name="__codelineno-18-3" href="#__codelineno-18-3"></a><span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;%d&quot;</span><span class="p">,</span><span class="w"> </span><span class="mi">0</span><span class="p">);</span>
<a id="__codelineno-18-4" name="__codelineno-18-4" href="#__codelineno-18-4"></a><span class="p">}</span>
<a id="__codelineno-18-5" name="__codelineno-18-5" href="#__codelineno-18-5"></a><span class="c1">// 算法 B 时间复杂度：线性阶</span>
<a id="__codelineno-18-5" name="__codelineno-18-5" href="#__codelineno-18-5"></a><span class="c1">// 算法 B 的时间复杂度：线性阶</span>
<a id="__codelineno-18-6" name="__codelineno-18-6" href="#__codelineno-18-6"></a><span class="kt">void</span><span class="w"> </span><span class="nf">algorithm_B</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-7" name="__codelineno-18-7" href="#__codelineno-18-7"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">n</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-8" name="__codelineno-18-8" href="#__codelineno-18-8"></a><span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;%d&quot;</span><span class="p">,</span><span class="w"> </span><span class="mi">0</span><span class="p">);</span>
<a id="__codelineno-18-9" name="__codelineno-18-9" href="#__codelineno-18-9"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-10" name="__codelineno-18-10" href="#__codelineno-18-10"></a><span class="p">}</span>
<a id="__codelineno-18-11" name="__codelineno-18-11" href="#__codelineno-18-11"></a><span class="c1">// 算法 C 时间复杂度：常数阶</span>
<a id="__codelineno-18-11" name="__codelineno-18-11" href="#__codelineno-18-11"></a><span class="c1">// 算法 C 的时间复杂度：常数阶</span>
<a id="__codelineno-18-12" name="__codelineno-18-12" href="#__codelineno-18-12"></a><span class="kt">void</span><span class="w"> </span><span class="nf">algorithm_C</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-13" name="__codelineno-18-13" href="#__codelineno-18-13"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="mi">1000000</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-14" name="__codelineno-18-14" href="#__codelineno-18-14"></a><span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;%d&quot;</span><span class="p">,</span><span class="w"> </span><span class="mi">0</span><span class="p">);</span>
@@ -3898,17 +3899,17 @@
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><pre><span></span><code><a id="__codelineno-19-1" name="__codelineno-19-1" href="#__codelineno-19-1"></a><span class="c1">// 算法 A 时间复杂度：常数阶</span>
<div class="highlight"><pre><span></span><code><a id="__codelineno-19-1" name="__codelineno-19-1" href="#__codelineno-19-1"></a><span class="c1">// 算法 A 的时间复杂度：常数阶</span>
<a id="__codelineno-19-2" name="__codelineno-19-2" href="#__codelineno-19-2"></a><span class="k">void</span><span class="w"> </span><span class="nf">algorithm_A</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-3" name="__codelineno-19-3" href="#__codelineno-19-3"></a><span class="w"> </span><span class="n">Console</span><span class="p">.</span><span class="n">WriteLine</span><span class="p">(</span><span class="m">0</span><span class="p">);</span>
<a id="__codelineno-19-4" name="__codelineno-19-4" href="#__codelineno-19-4"></a><span class="p">}</span>
<a id="__codelineno-19-5" name="__codelineno-19-5" href="#__codelineno-19-5"></a><span class="c1">// 算法 B 时间复杂度：线性阶</span>
<a id="__codelineno-19-5" name="__codelineno-19-5" href="#__codelineno-19-5"></a><span class="c1">// 算法 B 的时间复杂度：线性阶</span>
<a id="__codelineno-19-6" name="__codelineno-19-6" href="#__codelineno-19-6"></a><span class="k">void</span><span class="w"> </span><span class="nf">algorithm_B</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-7" name="__codelineno-19-7" href="#__codelineno-19-7"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">n</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-8" name="__codelineno-19-8" href="#__codelineno-19-8"></a><span class="w"> </span><span class="n">Console</span><span class="p">.</span><span class="n">WriteLine</span><span class="p">(</span><span class="m">0</span><span class="p">);</span>
<a id="__codelineno-19-9" name="__codelineno-19-9" href="#__codelineno-19-9"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-10" name="__codelineno-19-10" href="#__codelineno-19-10"></a><span class="p">}</span>
<a id="__codelineno-19-11" name="__codelineno-19-11" href="#__codelineno-19-11"></a><span class="c1">// 算法 C 时间复杂度：常数阶</span>
<a id="__codelineno-19-11" name="__codelineno-19-11" href="#__codelineno-19-11"></a><span class="c1">// 算法 C 的时间复杂度：常数阶</span>
<a id="__codelineno-19-12" name="__codelineno-19-12" href="#__codelineno-19-12"></a><span class="k">void</span><span class="w"> </span><span class="nf">algorithm_C</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-13" name="__codelineno-19-13" href="#__codelineno-19-13"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="m">1000000</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-14" name="__codelineno-19-14" href="#__codelineno-19-14"></a><span class="w"> </span><span class="n">Console</span><span class="p">.</span><span class="n">WriteLine</span><span class="p">(</span><span class="m">0</span><span class="p">);</span>
@@ -3917,19 +3918,19 @@
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><pre><span></span><code><a id="__codelineno-20-1" name="__codelineno-20-1" href="#__codelineno-20-1"></a><span class="c1">// 算法 A 时间复杂度：常数阶</span>
<div class="highlight"><pre><span></span><code><a id="__codelineno-20-1" name="__codelineno-20-1" href="#__codelineno-20-1"></a><span class="c1">// 算法 A 的时间复杂度：常数阶</span>
<a id="__codelineno-20-2" name="__codelineno-20-2" href="#__codelineno-20-2"></a><span class="kd">func</span> <span class="nf">algorithmA</span><span class="p">(</span><span class="n">n</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-20-3" name="__codelineno-20-3" href="#__codelineno-20-3"></a> <span class="bp">print</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>
<a id="__codelineno-20-4" name="__codelineno-20-4" href="#__codelineno-20-4"></a><span class="p">}</span>
<a id="__codelineno-20-5" name="__codelineno-20-5" href="#__codelineno-20-5"></a>
<a id="__codelineno-20-6" name="__codelineno-20-6" href="#__codelineno-20-6"></a><span class="c1">// 算法 B 时间复杂度：线性阶</span>
<a id="__codelineno-20-6" name="__codelineno-20-6" href="#__codelineno-20-6"></a><span class="c1">// 算法 B 的时间复杂度：线性阶</span>
<a id="__codelineno-20-7" name="__codelineno-20-7" href="#__codelineno-20-7"></a><span class="kd">func</span> <span class="nf">algorithmB</span><span class="p">(</span><span class="n">n</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-20-8" name="__codelineno-20-8" href="#__codelineno-20-8"></a> <span class="k">for</span> <span class="kc">_</span> <span class="k">in</span> <span class="mi">0</span> <span class="p">..</span><span class="o">&lt;</span> <span class="n">n</span> <span class="p">{</span>
<a id="__codelineno-20-9" name="__codelineno-20-9" href="#__codelineno-20-9"></a> <span class="bp">print</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>
<a id="__codelineno-20-10" name="__codelineno-20-10" href="#__codelineno-20-10"></a> <span class="p">}</span>
<a id="__codelineno-20-11" name="__codelineno-20-11" href="#__codelineno-20-11"></a><span class="p">}</span>
<a id="__codelineno-20-12" name="__codelineno-20-12" href="#__codelineno-20-12"></a>
<a id="__codelineno-20-13" name="__codelineno-20-13" href="#__codelineno-20-13"></a><span class="c1">// 算法 C 时间复杂度：常数阶</span>
<a id="__codelineno-20-13" name="__codelineno-20-13" href="#__codelineno-20-13"></a><span class="c1">// 算法 C 的时间复杂度：常数阶</span>
<a id="__codelineno-20-14" name="__codelineno-20-14" href="#__codelineno-20-14"></a><span class="kd">func</span> <span class="nf">algorithmC</span><span class="p">(</span><span class="n">n</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-20-15" name="__codelineno-20-15" href="#__codelineno-20-15"></a> <span class="k">for</span> <span class="kc">_</span> <span class="k">in</span> <span class="mi">0</span> <span class="p">..</span><span class="o">&lt;</span> <span class="mi">1000000</span> <span class="p">{</span>
<a id="__codelineno-20-16" name="__codelineno-20-16" href="#__codelineno-20-16"></a> <span class="bp">print</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>
@@ -3942,17 +3943,17 @@
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><pre><span></span><code><a id="__codelineno-22-1" name="__codelineno-22-1" href="#__codelineno-22-1"></a><span class="c1">// 算法 A 时间复杂度：常数阶</span>
<div class="highlight"><pre><span></span><code><a id="__codelineno-22-1" name="__codelineno-22-1" href="#__codelineno-22-1"></a><span class="c1">// 算法 A 的时间复杂度：常数阶</span>
<a id="__codelineno-22-2" name="__codelineno-22-2" href="#__codelineno-22-2"></a><span class="kt">void</span><span class="w"> </span><span class="n">algorithmA</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-3" name="__codelineno-22-3" href="#__codelineno-22-3"></a><span class="w"> </span><span class="n">print</span><span class="p">(</span><span class="m">0</span><span class="p">);</span>
<a id="__codelineno-22-4" name="__codelineno-22-4" href="#__codelineno-22-4"></a><span class="p">}</span>
<a id="__codelineno-22-5" name="__codelineno-22-5" href="#__codelineno-22-5"></a><span class="c1">// 算法 B 时间复杂度：线性阶</span>
<a id="__codelineno-22-5" name="__codelineno-22-5" href="#__codelineno-22-5"></a><span class="c1">// 算法 B 的时间复杂度：线性阶</span>
<a id="__codelineno-22-6" name="__codelineno-22-6" href="#__codelineno-22-6"></a><span class="kt">void</span><span class="w"> </span><span class="n">algorithmB</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-7" name="__codelineno-22-7" href="#__codelineno-22-7"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">n</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-8" name="__codelineno-22-8" href="#__codelineno-22-8"></a><span class="w"> </span><span class="n">print</span><span class="p">(</span><span class="m">0</span><span class="p">);</span>
<a id="__codelineno-22-9" name="__codelineno-22-9" href="#__codelineno-22-9"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-22-10" name="__codelineno-22-10" href="#__codelineno-22-10"></a><span class="p">}</span>
<a id="__codelineno-22-11" name="__codelineno-22-11" href="#__codelineno-22-11"></a><span class="c1">// 算法 C 时间复杂度：常数阶</span>
<a id="__codelineno-22-11" name="__codelineno-22-11" href="#__codelineno-22-11"></a><span class="c1">// 算法 C 的时间复杂度：常数阶</span>
<a id="__codelineno-22-12" name="__codelineno-22-12" href="#__codelineno-22-12"></a><span class="kt">void</span><span class="w"> </span><span class="n">algorithmC</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-13" name="__codelineno-22-13" href="#__codelineno-22-13"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="m">1000000</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-14" name="__codelineno-22-14" href="#__codelineno-22-14"></a><span class="w"> </span><span class="n">print</span><span class="p">(</span><span class="m">0</span><span class="p">);</span>
@@ -3961,17 +3962,17 @@
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><pre><span></span><code><a id="__codelineno-23-1" name="__codelineno-23-1" href="#__codelineno-23-1"></a><span class="c1">// 算法 A 时间复杂度：常数阶</span>
<div class="highlight"><pre><span></span><code><a id="__codelineno-23-1" name="__codelineno-23-1" href="#__codelineno-23-1"></a><span class="c1">// 算法 A 的时间复杂度：常数阶</span>
<a id="__codelineno-23-2" name="__codelineno-23-2" href="#__codelineno-23-2"></a><span class="k">fn</span> <span class="nf">algorithm_A</span><span class="p">(</span><span class="n">n</span>: <span class="kt">i32</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-3" name="__codelineno-23-3" href="#__codelineno-23-3"></a><span class="w"> </span><span class="fm">println!</span><span class="p">(</span><span class="s">&quot;{}&quot;</span><span class="p">,</span><span class="w"> </span><span class="mi">0</span><span class="p">);</span>
<a id="__codelineno-23-4" name="__codelineno-23-4" href="#__codelineno-23-4"></a><span class="p">}</span>
<a id="__codelineno-23-5" name="__codelineno-23-5" href="#__codelineno-23-5"></a><span class="c1">// 算法 B 时间复杂度：线性阶</span>
<a id="__codelineno-23-5" name="__codelineno-23-5" href="#__codelineno-23-5"></a><span class="c1">// 算法 B 的时间复杂度：线性阶</span>
<a id="__codelineno-23-6" name="__codelineno-23-6" href="#__codelineno-23-6"></a><span class="k">fn</span> <span class="nf">algorithm_B</span><span class="p">(</span><span class="n">n</span>: <span class="kt">i32</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-7" name="__codelineno-23-7" href="#__codelineno-23-7"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="n">_</span><span class="w"> </span><span class="k">in</span><span class="w"> </span><span class="mi">0</span><span class="o">..</span><span class="n">n</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-8" name="__codelineno-23-8" href="#__codelineno-23-8"></a><span class="w"> </span><span class="fm">println!</span><span class="p">(</span><span class="s">&quot;{}&quot;</span><span class="p">,</span><span class="w"> </span><span class="mi">0</span><span class="p">);</span>
<a id="__codelineno-23-9" name="__codelineno-23-9" href="#__codelineno-23-9"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-10" name="__codelineno-23-10" href="#__codelineno-23-10"></a><span class="p">}</span>
<a id="__codelineno-23-11" name="__codelineno-23-11" href="#__codelineno-23-11"></a><span class="c1">// 算法 C 时间复杂度：常数阶</span>
<a id="__codelineno-23-11" name="__codelineno-23-11" href="#__codelineno-23-11"></a><span class="c1">// 算法 C 的时间复杂度：常数阶</span>
<a id="__codelineno-23-12" name="__codelineno-23-12" href="#__codelineno-23-12"></a><span class="k">fn</span> <span class="nf">algorithm_C</span><span class="p">(</span><span class="n">n</span>: <span class="kt">i32</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-13" name="__codelineno-23-13" href="#__codelineno-23-13"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="n">_</span><span class="w"> </span><span class="k">in</span><span class="w"> </span><span class="mi">0</span><span class="o">..</span><span class="mi">1000000</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-14" name="__codelineno-23-14" href="#__codelineno-23-14"></a><span class="w"> </span><span class="fm">println!</span><span class="p">(</span><span class="s">&quot;{}&quot;</span><span class="p">,</span><span class="w"> </span><span class="mi">0</span><span class="p">);</span>
@@ -3984,15 +3985,17 @@
<p>算法 <code>A</code> 只有 <span class="arithmatex">\(1\)</span> 个打印操作，算法运行时间不随着 <span class="arithmatex">\(n\)</span> 增大而增长。我们称此算法的时间复杂度为「常数阶」。</p>
<p>算法 <code>B</code> 中的打印操作需要循环 <span class="arithmatex">\(n\)</span> 次，算法运行时间随着 <span class="arithmatex">\(n\)</span> 增大呈线性增长。此算法的时间复杂度被称为「线性阶」。</p>
<p>算法 <code>C</code> 中的打印操作需要循环 <span class="arithmatex">\(1000000\)</span> 次，虽然运行时间很长，但它与输入数据大小 <span class="arithmatex">\(n\)</span> 无关。因此 <code>C</code> 的时间复杂度和 <code>A</code> 相同，仍为「常数阶」。</p>
<p><img alt="算法 A, B, C 的时间增长趋势" src="../time_complexity.assets/time_complexity_simple_example.png" /></p>
<p align="center"> 图：算法 A, B, C 的时间增长趋势 </p>
<p><img alt="算法 A 、B 和 C 的时间增长趋势" src="../time_complexity.assets/time_complexity_simple_example.png" /></p>
<p align="center"> 图：算法 A 、B 和 C 的时间增长趋势 </p>
<p>相较于直接统计算法运行时间，时间复杂度分析有哪些特点呢？</p>
<p><strong>时间复杂度能够有效评估算法效率</strong>。例如，算法 <code>B</code> 的运行时间呈线性增长，在 <span class="arithmatex">\(n &gt; 1\)</span> 时比算法 <code>A</code> 更慢，在 <span class="arithmatex">\(n &gt; 1000000\)</span> 时比算法 <code>C</code> 更慢。事实上，只要输入数据大小 <span class="arithmatex">\(n\)</span> 足够大，复杂度为“常数阶”的算法一定优于“线性阶”的算法，这正是时间增长趋势所表达的含义。</p>
<p><strong>时间复杂度的推算方法更简便</strong>。显然，运行平台和计算操作类型都与算法运行时间的增长趋势无关。因此在时间复杂度分析中，我们可以简单地将所有计算操作的执行时间视为相同的“单位时间”，从而将“计算操作的运行时间的统计”简化为“计算操作的数量的统计”，这样以来估算难度就大大降低了。</p>
<p><strong>时间复杂度也存在一定的局限性</strong>。例如，尽管算法 <code>A</code> 和 <code>C</code> 的时间复杂度相同，但实际运行时间差别很大。同样，尽管算法 <code>B</code> 的时间复杂度比 <code>C</code> 高，但在输入数据大小 <span class="arithmatex">\(n\)</span> 较小时，算法 <code>B</code> 明显优于算法 <code>C</code> 。在这些情况下，我们很难仅凭时间复杂度判断算法效率高低。当然，尽管存在上述问题，复杂度分析仍然是评判算法效率最有效且常用的方法。</p>
<ul>
<li><strong>时间复杂度能够有效评估算法效率</strong>。例如，算法 <code>B</code> 的运行时间呈线性增长，在 <span class="arithmatex">\(n &gt; 1\)</span> 时比算法 <code>A</code> 更慢，在 <span class="arithmatex">\(n &gt; 1000000\)</span> 时比算法 <code>C</code> 更慢。事实上，只要输入数据大小 <span class="arithmatex">\(n\)</span> 足够大，复杂度为“常数阶”的算法一定优于“线性阶”的算法，这正是时间增长趋势所表达的含义。</li>
<li><strong>时间复杂度的推算方法更简便</strong>。显然，运行平台和计算操作类型都与算法运行时间的增长趋势无关。因此在时间复杂度分析中，我们可以简单地将所有计算操作的执行时间视为相同的“单位时间”，从而将“计算操作的运行时间的统计”简化为“计算操作的数量的统计”，这样以来估算难度就大大降低了。</li>
<li><strong>时间复杂度也存在一定的局限性</strong>。例如，尽管算法 <code>A</code> 和 <code>C</code> 的时间复杂度相同，但实际运行时间差别很大。同样，尽管算法 <code>B</code> 的时间复杂度比 <code>C</code> 高，但在输入数据大小 <span class="arithmatex">\(n\)</span> 较小时，算法 <code>B</code> 明显优于算法 <code>C</code> 。在这些情况下，我们很难仅凭时间复杂度判断算法效率的高低。当然，尽管存在上述问题，复杂度分析仍然是评判算法效率最有效且常用的方法。</li>
</ul>
<h2 id="222">2.2.2 &nbsp; 函数渐近上界<a class="headerlink" href="#222" title="Permanent link">&para;</a></h2>
<p>给定一个函数 <code>algorithm()</code> ：</p>
<p>给定一个输入大小为 <span class="arithmatex">\(n\)</span> 的函数：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="3:12"><input checked="checked" id="__tabbed_3_1" name="__tabbed_3" type="radio" /><input id="__tabbed_3_2" name="__tabbed_3" type="radio" /><input id="__tabbed_3_3" name="__tabbed_3" type="radio" /><input id="__tabbed_3_4" name="__tabbed_3" type="radio" /><input id="__tabbed_3_5" name="__tabbed_3" type="radio" /><input id="__tabbed_3_6" name="__tabbed_3" type="radio" /><input id="__tabbed_3_7" name="__tabbed_3" type="radio" /><input id="__tabbed_3_8" name="__tabbed_3" type="radio" /><input id="__tabbed_3_9" name="__tabbed_3" type="radio" /><input id="__tabbed_3_10" name="__tabbed_3" type="radio" /><input id="__tabbed_3_11" name="__tabbed_3" type="radio" /><input id="__tabbed_3_12" name="__tabbed_3" type="radio" /><div class="tabbed-labels"><label for="__tabbed_3_1">Java</label><label for="__tabbed_3_2">C++</label><label for="__tabbed_3_3">Python</label><label for="__tabbed_3_4">Go</label><label for="__tabbed_3_5">JS</label><label for="__tabbed_3_6">TS</label><label for="__tabbed_3_7">C</label><label for="__tabbed_3_8">C#</label><label for="__tabbed_3_9">Swift</label><label for="__tabbed_3_10">Zig</label><label for="__tabbed_3_11">Dart</label><label for="__tabbed_3_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -4132,12 +4135,12 @@
</div>
</div>
</div>
<p>设算法的计算操作数量是一个关于输入数据大小 <span class="arithmatex">\(n\)</span> 的函数，记为 <span class="arithmatex">\(T(n)\)</span> ，则以上函数的的操作数量为：</p>
<p>设算法的操作数量是一个关于输入数据大小 <span class="arithmatex">\(n\)</span> 的函数，记为 <span class="arithmatex">\(T(n)\)</span> ，则以上函数的的操作数量为：</p>
<div class="arithmatex">\[
T(n) = 3 + 2n
\]</div>
<p><span class="arithmatex">\(T(n)\)</span> 是一次函数，说明时间的增长趋势是线性的，因此其时间复杂度是线性阶。</p>
<p>我们将线性阶的时间复杂度记为 <span class="arithmatex">\(O(n)\)</span> ，这个数学符号称为「大 <span class="arithmatex">\(O\)</span> 记号 Big-<span class="arithmatex">\(O\)</span> Notation」，表示函数 <span class="arithmatex">\(T(n)\)</span> 的「渐近上界 Asymptotic Upper Bound」。</p>
<p><span class="arithmatex">\(T(n)\)</span> 是一次函数，说明其运行时间的增长趋势是线性的，因此它的时间复杂度是线性阶。</p>
<p>我们将线性阶的时间复杂度记为 <span class="arithmatex">\(O(n)\)</span> ，这个数学符号称为「大 <span class="arithmatex">\(O\)</span> 记号 big-<span class="arithmatex">\(O\)</span> notation」，表示函数 <span class="arithmatex">\(T(n)\)</span> 的「渐近上界 asymptotic upper bound」。</p>
<p>时间复杂度分析本质上是计算“操作数量函数 <span class="arithmatex">\(T(n)\)</span>”的渐近上界。接下来，我们来看函数渐近上界的数学定义。</p>
<div class="admonition abstract">
<p class="admonition-title">函数渐近上界</p>
@@ -4150,21 +4153,21 @@ $$
T(n) = O(f(n))
$$</p>
</div>
<p>如下图所示，计算渐近上界就是寻找一个函数 <span class="arithmatex">\(f(n)\)</span> ，使得当 <span class="arithmatex">\(n\)</span> 趋向于无穷大时，<span class="arithmatex">\(T(n)\)</span> 和 <span class="arithmatex">\(f(n)\)</span> 处于相同的增长级别，仅相差一个常数项 <span class="arithmatex">\(c\)</span> 的倍数。</p>
<p><img alt="函数的渐近上界" src="../time_complexity.assets/asymptotic_upper_bound.png" /></p>
<p align="center"> 图：函数的渐近上界 </p>
<p>也就是说，计算渐近上界就是寻找一个函数 <span class="arithmatex">\(f(n)\)</span> ，使得当 <span class="arithmatex">\(n\)</span> 趋向于无穷大时，<span class="arithmatex">\(T(n)\)</span> 和 <span class="arithmatex">\(f(n)\)</span> 处于相同的增长级别，仅相差一个常数项 <span class="arithmatex">\(c\)</span> 的倍数。</p>
<h2 id="223">2.2.3 &nbsp; 推算方法<a class="headerlink" href="#223" title="Permanent link">&para;</a></h2>
<p>渐近上界的数学味儿有点重，如果你感觉没有完全理解，也无需担心。因为在实际使用中，我们只需要掌握推算方法，数学意义可以逐渐领悟。</p>
<p>渐近上界的数学味儿有点重，如果你感觉没有完全理解，也无须担心。因为在实际使用中，我们只需要掌握推算方法，数学意义就可以逐渐领悟。</p>
<p>根据定义，确定 <span class="arithmatex">\(f(n)\)</span> 之后，我们便可得到时间复杂度 <span class="arithmatex">\(O(f(n))\)</span> 。那么如何确定渐近上界 <span class="arithmatex">\(f(n)\)</span> 呢？总体分为两步：首先统计操作数量，然后判断渐近上界。</p>
<h3 id="1">1. &nbsp; 第一步：统计操作数量<a class="headerlink" href="#1" title="Permanent link">&para;</a></h3>
<p>针对代码，逐行从上到下计算即可。然而，由于上述 <span class="arithmatex">\(c \cdot f(n)\)</span> 中的常数项 <span class="arithmatex">\(c\)</span> 可以取任意大小，<strong>因此操作数量 <span class="arithmatex">\(T(n)\)</span> 中的各种系数、常数项都可以被忽略</strong>。根据此原则，可以总结出以下计数简化技巧：</p>
<p>针对代码，逐行从上到下计算即可。然而，由于上述 <span class="arithmatex">\(c \cdot f(n)\)</span> 中的常数项 <span class="arithmatex">\(c\)</span> 可以取任意大小，<strong>因此操作数量 <span class="arithmatex">\(T(n)\)</span> 中的各种系数、常数项都可以被忽略</strong>。根据此原则，可以总结出以下计数简化技巧。</p>
<ol>
<li><strong>忽略 <span class="arithmatex">\(T(n)\)</span> 中的常数项</strong>。因为它们都与 <span class="arithmatex">\(n\)</span> 无关，所以对时间复杂度不产生影响。</li>
<li><strong>省略所有系数</strong>。例如，循环 <span class="arithmatex">\(2n\)</span> 次、<span class="arithmatex">\(5n + 1\)</span> 次等，都可以简化记为 <span class="arithmatex">\(n\)</span> 次，因为 <span class="arithmatex">\(n\)</span> 前面的系数对时间复杂度没有影响。</li>
<li><strong>循环嵌套时使用乘法</strong>。总操作数量等于外层循环和内层循环操作数量之积，每一层循环依然可以分别套用上述 <code>1.</code> 和 <code>2.</code> 技巧。</li>
</ol>
<p>以下示例展示了使用上述技巧前、后的统计结果。两者推出的时间复杂度相同，即为 <span class="arithmatex">\(O(n^2)\)</span> 。</p>
<p>以下代码与公式分别展示了使用上述技巧前后的统计结果。两者推出的时间复杂度相同，都为 <span class="arithmatex">\(O(n^2)\)</span> 。</p>
<div class="arithmatex">\[
\begin{aligned}
T(n) &amp; = 2n(n + 1) + (5n + 1) + 2 &amp; \text{完整统计 (-.-|||)} \newline
@@ -4368,7 +4371,7 @@ T(n) &amp; = n^2 + n &amp; \text{偷懒统计 (o.O)}
<h3 id="2">2. &nbsp; 第二步：判断渐近上界<a class="headerlink" href="#2" title="Permanent link">&para;</a></h3>
<p><strong>时间复杂度由多项式 <span class="arithmatex">\(T(n)\)</span> 中最高阶的项来决定</strong>。这是因为在 <span class="arithmatex">\(n\)</span> 趋于无穷大时，最高阶的项将发挥主导作用，其他项的影响都可以被忽略。</p>
<p>以下表格展示了一些例子，其中一些夸张的值是为了强调“系数无法撼动阶数”这一结论。当 <span class="arithmatex">\(n\)</span> 趋于无穷大时，这些常数变得无足轻重。</p>
<p align="center"> 表：多项式时间复杂度示例 </p>
<p align="center"> 表：不同操作数量对应的时间复杂度 </p>
<div class="center-table">
<table>
@@ -4410,16 +4413,16 @@ O(1) &lt; O(\log n) &lt; O(n) &lt; O(n \log n) &lt; O(n^2) &lt; O(2^n) &lt; O(n!
\text{常数阶} &lt; \text{对数阶} &lt; \text{线性阶} &lt; \text{线性对数阶} &lt; \text{平方阶} &lt; \text{指数阶} &lt; \text{阶乘阶}
\end{aligned}
\]</div>
<p><img alt="时间复杂度的常见类型" src="../time_complexity.assets/time_complexity_common_types.png" /></p>
<p align="center"> 图：时间复杂度的常见类型 </p>
<p><img alt="常见的时间复杂度类型" src="../time_complexity.assets/time_complexity_common_types.png" /></p>
<p align="center"> 图：常见的时间复杂度类型 </p>
<div class="admonition tip">
<p class="admonition-title">Tip</p>
<p>部分示例代码需要一些预备知识，包括数组、递归等。如果你遇到不理解的部分，可以在学习完后面章节后再回顾。现阶段，请先专注于理解时间复杂度的含义和推算方法。</p>
<p>部分示例代码需要一些预备知识，包括数组、递归等。如果你遇到不理解的部分，可以在学完后面章节后再回顾。现阶段，请先专注于理解时间复杂度的含义和推算方法。</p>
</div>
<h3 id="1-o1">1. &nbsp; 常数阶 <span class="arithmatex">\(O(1)\)</span><a class="headerlink" href="#1-o1" title="Permanent link">&para;</a></h3>
<p>常数阶的操作数量与输入数据大小 <span class="arithmatex">\(n\)</span> 无关，即不随着 <span class="arithmatex">\(n\)</span> 的变化而变化。</p>
<p>对于以下算法，尽管操作数量 <code>size</code> 可能很大，但由于其与数据大小 <span class="arithmatex">\(n\)</span> 无关，因此时间复杂度仍为 <span class="arithmatex">\(O(1)\)</span> 。</p>
<p>对于以下算法，尽管操作数量 <code>size</code> 可能很大，但由于其与输入数据大小 <span class="arithmatex">\(n\)</span> 无关，因此时间复杂度仍为 <span class="arithmatex">\(O(1)\)</span> ：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="5:12"><input checked="checked" id="__tabbed_5_1" name="__tabbed_5" type="radio" /><input id="__tabbed_5_2" name="__tabbed_5" type="radio" /><input id="__tabbed_5_3" name="__tabbed_5" type="radio" /><input id="__tabbed_5_4" name="__tabbed_5" type="radio" /><input id="__tabbed_5_5" name="__tabbed_5" type="radio" /><input id="__tabbed_5_6" name="__tabbed_5" type="radio" /><input id="__tabbed_5_7" name="__tabbed_5" type="radio" /><input id="__tabbed_5_8" name="__tabbed_5" type="radio" /><input id="__tabbed_5_9" name="__tabbed_5" type="radio" /><input id="__tabbed_5_10" name="__tabbed_5" type="radio" /><input id="__tabbed_5_11" name="__tabbed_5" type="radio" /><input id="__tabbed_5_12" name="__tabbed_5" type="radio" /><div class="tabbed-labels"><label for="__tabbed_5_1">Java</label><label for="__tabbed_5_2">C++</label><label for="__tabbed_5_3">Python</label><label for="__tabbed_5_4">Go</label><label for="__tabbed_5_5">JS</label><label for="__tabbed_5_6">TS</label><label for="__tabbed_5_7">C</label><label for="__tabbed_5_8">C#</label><label for="__tabbed_5_9">Swift</label><label for="__tabbed_5_10">Zig</label><label for="__tabbed_5_11">Dart</label><label for="__tabbed_5_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -4564,7 +4567,7 @@ O(1) &lt; O(\log n) &lt; O(n) &lt; O(n \log n) &lt; O(n^2) &lt; O(2^n) &lt; O(n!
</div>
</div>
<h3 id="2-on">2. &nbsp; 线性阶 <span class="arithmatex">\(O(n)\)</span><a class="headerlink" href="#2-on" title="Permanent link">&para;</a></h3>
<p>线性阶的操作数量相对于输入数据大小以线性级别增长。线性阶通常出现在单层循环中。</p>
<p>线性阶的操作数量相对于输入数据大小 <span class="arithmatex">\(n\)</span> 以线性级别增长。线性阶通常出现在单层循环中：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="6:12"><input checked="checked" id="__tabbed_6_1" name="__tabbed_6" type="radio" /><input id="__tabbed_6_2" name="__tabbed_6" type="radio" /><input id="__tabbed_6_3" name="__tabbed_6" type="radio" /><input id="__tabbed_6_4" name="__tabbed_6" type="radio" /><input id="__tabbed_6_5" name="__tabbed_6" type="radio" /><input id="__tabbed_6_6" name="__tabbed_6" type="radio" /><input id="__tabbed_6_7" name="__tabbed_6" type="radio" /><input id="__tabbed_6_8" name="__tabbed_6" type="radio" /><input id="__tabbed_6_9" name="__tabbed_6" type="radio" /><input id="__tabbed_6_10" name="__tabbed_6" type="radio" /><input id="__tabbed_6_11" name="__tabbed_6" type="radio" /><input id="__tabbed_6_12" name="__tabbed_6" type="radio" /><div class="tabbed-labels"><label for="__tabbed_6_1">Java</label><label for="__tabbed_6_2">C++</label><label for="__tabbed_6_3">Python</label><label for="__tabbed_6_4">Go</label><label for="__tabbed_6_5">JS</label><label for="__tabbed_6_6">TS</label><label for="__tabbed_6_7">C</label><label for="__tabbed_6_8">C#</label><label for="__tabbed_6_9">Swift</label><label for="__tabbed_6_10">Zig</label><label for="__tabbed_6_11">Dart</label><label for="__tabbed_6_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -4693,7 +4696,7 @@ O(1) &lt; O(\log n) &lt; O(n) &lt; O(n \log n) &lt; O(n^2) &lt; O(2^n) &lt; O(n!
</div>
</div>
</div>
<p>遍历数组和遍历链表等操作的时间复杂度均为 <span class="arithmatex">\(O(n)\)</span> ，其中 <span class="arithmatex">\(n\)</span> 为数组或链表的长度。</p>
<p>遍历数组和遍历链表等操作的时间复杂度均为 <span class="arithmatex">\(O(n)\)</span> ，其中 <span class="arithmatex">\(n\)</span> 为数组或链表的长度：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="7:12"><input checked="checked" id="__tabbed_7_1" name="__tabbed_7" type="radio" /><input id="__tabbed_7_2" name="__tabbed_7" type="radio" /><input id="__tabbed_7_3" name="__tabbed_7" type="radio" /><input id="__tabbed_7_4" name="__tabbed_7" type="radio" /><input id="__tabbed_7_5" name="__tabbed_7" type="radio" /><input id="__tabbed_7_6" name="__tabbed_7" type="radio" /><input id="__tabbed_7_7" name="__tabbed_7" type="radio" /><input id="__tabbed_7_8" name="__tabbed_7" type="radio" /><input id="__tabbed_7_9" name="__tabbed_7" type="radio" /><input id="__tabbed_7_10" name="__tabbed_7" type="radio" /><input id="__tabbed_7_11" name="__tabbed_7" type="radio" /><input id="__tabbed_7_12" name="__tabbed_7" type="radio" /><div class="tabbed-labels"><label for="__tabbed_7_1">Java</label><label for="__tabbed_7_2">C++</label><label for="__tabbed_7_3">Python</label><label for="__tabbed_7_4">Go</label><label for="__tabbed_7_5">JS</label><label for="__tabbed_7_6">TS</label><label for="__tabbed_7_7">C</label><label for="__tabbed_7_8">C#</label><label for="__tabbed_7_9">Swift</label><label for="__tabbed_7_10">Zig</label><label for="__tabbed_7_11">Dart</label><label for="__tabbed_7_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -4840,9 +4843,9 @@ O(1) &lt; O(\log n) &lt; O(n) &lt; O(n \log n) &lt; O(n^2) &lt; O(2^n) &lt; O(n!
</div>
</div>
</div>
<p>值得注意的是，<strong>数据大小 <span class="arithmatex">\(n\)</span> 需根据输入数据的类型来具体确定</strong>。比如在第一个示例中，变量 <span class="arithmatex">\(n\)</span> 为输入数据大小；在第二个示例中，数组长度 <span class="arithmatex">\(n\)</span> 为数据大小。</p>
<p>值得注意的是，<strong>输入数据大小 <span class="arithmatex">\(n\)</span> 需根据输入数据的类型来具体确定</strong>。比如在第一个示例中，变量 <span class="arithmatex">\(n\)</span> 为输入数据大小；在第二个示例中，数组长度 <span class="arithmatex">\(n\)</span> 为数据大小。</p>
<h3 id="3-on2">3. &nbsp; 平方阶 <span class="arithmatex">\(O(n^2)\)</span><a class="headerlink" href="#3-on2" title="Permanent link">&para;</a></h3>
<p>平方阶的操作数量相对于输入数据大小以平方级别增长。平方阶通常出现在嵌套循环中，外层循环和内层循环都为 <span class="arithmatex">\(O(n)\)</span> ，因此总体为 <span class="arithmatex">\(O(n^2)\)</span> 。</p>
<p>平方阶的操作数量相对于输入数据大小以平方级别增长。平方阶通常出现在嵌套循环中，外层循环和内层循环都为 <span class="arithmatex">\(O(n)\)</span> ，因此总体为 <span class="arithmatex">\(O(n^2)\)</span> ：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="8:12"><input checked="checked" id="__tabbed_8_1" name="__tabbed_8" type="radio" /><input id="__tabbed_8_2" name="__tabbed_8" type="radio" /><input id="__tabbed_8_3" name="__tabbed_8" type="radio" /><input id="__tabbed_8_4" name="__tabbed_8" type="radio" /><input id="__tabbed_8_5" name="__tabbed_8" type="radio" /><input id="__tabbed_8_6" name="__tabbed_8" type="radio" /><input id="__tabbed_8_7" name="__tabbed_8" type="radio" /><input id="__tabbed_8_8" name="__tabbed_8" type="radio" /><input id="__tabbed_8_9" name="__tabbed_8" type="radio" /><input id="__tabbed_8_10" name="__tabbed_8" type="radio" /><input id="__tabbed_8_11" name="__tabbed_8" type="radio" /><input id="__tabbed_8_12" name="__tabbed_8" type="radio" /><div class="tabbed-labels"><label for="__tabbed_8_1">Java</label><label for="__tabbed_8_2">C++</label><label for="__tabbed_8_3">Python</label><label for="__tabbed_8_4">Go</label><label for="__tabbed_8_5">JS</label><label for="__tabbed_8_6">TS</label><label for="__tabbed_8_7">C</label><label for="__tabbed_8_8">C#</label><label for="__tabbed_8_9">Swift</label><label for="__tabbed_8_10">Zig</label><label for="__tabbed_8_11">Dart</label><label for="__tabbed_8_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -5014,10 +5017,11 @@ O(1) &lt; O(\log n) &lt; O(n) &lt; O(n \log n) &lt; O(n^2) &lt; O(2^n) &lt; O(n!
</div>
</div>
</div>
<p><img alt="常数阶、线性阶、平方阶的时间复杂度" src="../time_complexity.assets/time_complexity_constant_linear_quadratic.png" /></p>
<p align="center"> 图：常数阶、线性阶、平方阶的时间复杂度 </p>
<p>下图对比了常数阶、线性阶和平方阶三种时间复杂度。</p>
<p><img alt="常数阶、线性阶和平方阶的时间复杂度" src="../time_complexity.assets/time_complexity_constant_linear_quadratic.png" /></p>
<p align="center"> 图：常数阶、线性阶和平方阶的时间复杂度 </p>
<p>以「冒泡排序」为例，外层循环执行 <span class="arithmatex">\(n - 1\)</span> 次，内层循环执行 <span class="arithmatex">\(n-1, n-2, \cdots, 2, 1\)</span> 次，平均为 <span class="arithmatex">\(\frac{n}{2}\)</span> 次，因此时间复杂度为 <span class="arithmatex">\(O(n^2)\)</span> 。</p>
<p>以冒泡排序为例，外层循环执行 <span class="arithmatex">\(n - 1\)</span> 次，内层循环执行 <span class="arithmatex">\(n-1, n-2, \cdots, 2, 1\)</span> 次，平均为 <span class="arithmatex">\(\frac{n}{2}\)</span> 次，因此时间复杂度为 <span class="arithmatex">\(O(n^2)\)</span> ：</p>
<div class="arithmatex">\[
O((n - 1) \frac{n}{2}) = O(n^2)
\]</div>
@@ -5274,8 +5278,7 @@ O((n - 1) \frac{n}{2}) = O(n^2)
</div>
</div>
<h3 id="4-o2n">4. &nbsp; 指数阶 <span class="arithmatex">\(O(2^n)\)</span><a class="headerlink" href="#4-o2n" title="Permanent link">&para;</a></h3>
<p>生物学的“细胞分裂”是指数阶增长的典型例子：初始状态为 <span class="arithmatex">\(1\)</span> 个细胞，分裂一轮后变为 <span class="arithmatex">\(2\)</span> 个，分裂两轮后变为 <span class="arithmatex">\(4\)</span> 个，以此类推，分裂 <span class="arithmatex">\(n\)</span> 轮后有 <span class="arithmatex">\(2^n\)</span> 个细胞。</p>
<p>以下代码模拟了细胞分裂的过程。</p>
<p>生物学的“细胞分裂”是指数阶增长的典型例子：初始状态为 <span class="arithmatex">\(1\)</span> 个细胞，分裂一轮后变为 <span class="arithmatex">\(2\)</span> 个，分裂两轮后变为 <span class="arithmatex">\(4\)</span> 个，以此类推，分裂 <span class="arithmatex">\(n\)</span> 轮后有 <span class="arithmatex">\(2^n\)</span> 个细胞。相关代码如下：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="10:12"><input checked="checked" id="__tabbed_10_1" name="__tabbed_10" type="radio" /><input id="__tabbed_10_2" name="__tabbed_10" type="radio" /><input id="__tabbed_10_3" name="__tabbed_10" type="radio" /><input id="__tabbed_10_4" name="__tabbed_10" type="radio" /><input id="__tabbed_10_5" name="__tabbed_10" type="radio" /><input id="__tabbed_10_6" name="__tabbed_10" type="radio" /><input id="__tabbed_10_7" name="__tabbed_10" type="radio" /><input id="__tabbed_10_8" name="__tabbed_10" type="radio" /><input id="__tabbed_10_9" name="__tabbed_10" type="radio" /><input id="__tabbed_10_10" name="__tabbed_10" type="radio" /><input id="__tabbed_10_11" name="__tabbed_10" type="radio" /><input id="__tabbed_10_12" name="__tabbed_10" type="radio" /><div class="tabbed-labels"><label for="__tabbed_10_1">Java</label><label for="__tabbed_10_2">C++</label><label for="__tabbed_10_3">Python</label><label for="__tabbed_10_4">Go</label><label for="__tabbed_10_5">JS</label><label for="__tabbed_10_6">TS</label><label for="__tabbed_10_7">C</label><label for="__tabbed_10_8">C#</label><label for="__tabbed_10_9">Swift</label><label for="__tabbed_10_10">Zig</label><label for="__tabbed_10_11">Dart</label><label for="__tabbed_10_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -5478,10 +5481,11 @@ O((n - 1) \frac{n}{2}) = O(n^2)
</div>
</div>
</div>
<p>下图展示了细胞分裂的过程。</p>
<p><img alt="指数阶的时间复杂度" src="../time_complexity.assets/time_complexity_exponential.png" /></p>
<p align="center"> 图：指数阶的时间复杂度 </p>
<p>在实际算法中，指数阶常出现于递归函数。例如以下代码，其递归地一分为二，经过 <span class="arithmatex">\(n\)</span> 次分裂后停止。</p>
<p>在实际算法中，指数阶常出现于递归函数中。例如以下代码，其递归地一分为二，经过 <span class="arithmatex">\(n\)</span> 次分裂后停止：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="11:12"><input checked="checked" id="__tabbed_11_1" name="__tabbed_11" type="radio" /><input id="__tabbed_11_2" name="__tabbed_11" type="radio" /><input id="__tabbed_11_3" name="__tabbed_11" type="radio" /><input id="__tabbed_11_4" name="__tabbed_11" type="radio" /><input id="__tabbed_11_5" name="__tabbed_11" type="radio" /><input id="__tabbed_11_6" name="__tabbed_11" type="radio" /><input id="__tabbed_11_7" name="__tabbed_11" type="radio" /><input id="__tabbed_11_8" name="__tabbed_11" type="radio" /><input id="__tabbed_11_9" name="__tabbed_11" type="radio" /><input id="__tabbed_11_10" name="__tabbed_11" type="radio" /><input id="__tabbed_11_11" name="__tabbed_11" type="radio" /><input id="__tabbed_11_12" name="__tabbed_11" type="radio" /><div class="tabbed-labels"><label for="__tabbed_11_1">Java</label><label for="__tabbed_11_2">C++</label><label for="__tabbed_11_3">Python</label><label for="__tabbed_11_4">Go</label><label for="__tabbed_11_5">JS</label><label for="__tabbed_11_6">TS</label><label for="__tabbed_11_7">C</label><label for="__tabbed_11_8">C#</label><label for="__tabbed_11_9">Swift</label><label for="__tabbed_11_10">Zig</label><label for="__tabbed_11_11">Dart</label><label for="__tabbed_11_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -5593,7 +5597,7 @@ O((n - 1) \frac{n}{2}) = O(n^2)
</div>
<p>指数阶增长非常迅速，在穷举法（暴力搜索、回溯等）中比较常见。对于数据规模较大的问题，指数阶是不可接受的，通常需要使用「动态规划」或「贪心」等算法来解决。</p>
<h3 id="5-olog-n">5. &nbsp; 对数阶 <span class="arithmatex">\(O(\log n)\)</span><a class="headerlink" href="#5-olog-n" title="Permanent link">&para;</a></h3>
<p>与指数阶相反，对数阶反映了“每轮缩减到一半”的情况。设输入数据大小为 <span class="arithmatex">\(n\)</span> ，由于每轮缩减到一半，因此循环次数是 <span class="arithmatex">\(\log_2 n\)</span> ，即 <span class="arithmatex">\(2^n\)</span> 的反函数。</p>
<p>与指数阶相反，对数阶反映了“每轮缩减到一半”的情况。设输入数据大小为 <span class="arithmatex">\(n\)</span> ，由于每轮缩减到一半，因此循环次数是 <span class="arithmatex">\(\log_2 n\)</span> ，即 <span class="arithmatex">\(2^n\)</span> 的反函数。相关代码如下：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="12:12"><input checked="checked" id="__tabbed_12_1" name="__tabbed_12" type="radio" /><input id="__tabbed_12_2" name="__tabbed_12" type="radio" /><input id="__tabbed_12_3" name="__tabbed_12" type="radio" /><input id="__tabbed_12_4" name="__tabbed_12" type="radio" /><input id="__tabbed_12_5" name="__tabbed_12" type="radio" /><input id="__tabbed_12_6" name="__tabbed_12" type="radio" /><input id="__tabbed_12_7" name="__tabbed_12" type="radio" /><input id="__tabbed_12_8" name="__tabbed_12" type="radio" /><input id="__tabbed_12_9" name="__tabbed_12" type="radio" /><input id="__tabbed_12_10" name="__tabbed_12" type="radio" /><input id="__tabbed_12_11" name="__tabbed_12" type="radio" /><input id="__tabbed_12_12" name="__tabbed_12" type="radio" /><div class="tabbed-labels"><label for="__tabbed_12_1">Java</label><label for="__tabbed_12_2">C++</label><label for="__tabbed_12_3">Python</label><label for="__tabbed_12_4">Go</label><label for="__tabbed_12_5">JS</label><label for="__tabbed_12_6">TS</label><label for="__tabbed_12_7">C</label><label for="__tabbed_12_8">C#</label><label for="__tabbed_12_9">Swift</label><label for="__tabbed_12_10">Zig</label><label for="__tabbed_12_11">Dart</label><label for="__tabbed_12_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -5746,7 +5750,7 @@ O((n - 1) \frac{n}{2}) = O(n^2)
<p><img alt="对数阶的时间复杂度" src="../time_complexity.assets/time_complexity_logarithmic.png" /></p>
<p align="center"> 图：对数阶的时间复杂度 </p>
<p>与指数阶类似，对数阶也常出现于递归函数。以下代码形成了一个高度为 <span class="arithmatex">\(\log_2 n\)</span> 的递归树。</p>
<p>与指数阶类似，对数阶也常出现于递归函数中。以下代码形成了一个高度为 <span class="arithmatex">\(\log_2 n\)</span> 的递归树：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="13:12"><input checked="checked" id="__tabbed_13_1" name="__tabbed_13" type="radio" /><input id="__tabbed_13_2" name="__tabbed_13" type="radio" /><input id="__tabbed_13_3" name="__tabbed_13" type="radio" /><input id="__tabbed_13_4" name="__tabbed_13" type="radio" /><input id="__tabbed_13_5" name="__tabbed_13" type="radio" /><input id="__tabbed_13_6" name="__tabbed_13" type="radio" /><input id="__tabbed_13_7" name="__tabbed_13" type="radio" /><input id="__tabbed_13_8" name="__tabbed_13" type="radio" /><input id="__tabbed_13_9" name="__tabbed_13" type="radio" /><input id="__tabbed_13_10" name="__tabbed_13" type="radio" /><input id="__tabbed_13_11" name="__tabbed_13" type="radio" /><input id="__tabbed_13_12" name="__tabbed_13" type="radio" /><div class="tabbed-labels"><label for="__tabbed_13_1">Java</label><label for="__tabbed_13_2">C++</label><label for="__tabbed_13_3">Python</label><label for="__tabbed_13_4">Go</label><label for="__tabbed_13_5">JS</label><label for="__tabbed_13_6">TS</label><label for="__tabbed_13_7">C</label><label for="__tabbed_13_8">C#</label><label for="__tabbed_13_9">Swift</label><label for="__tabbed_13_10">Zig</label><label for="__tabbed_13_11">Dart</label><label for="__tabbed_13_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -5856,10 +5860,9 @@ O((n - 1) \frac{n}{2}) = O(n^2)
</div>
</div>
</div>
<p>对数阶常出现于基于「分治」的算法中，体现了“一分为多”和“化繁为简”的算法思想。它增长缓慢，是理想的时间复杂度，仅次于常数阶。</p>
<p>对数阶常出现于基于分治策略的算法中，体现了“一分为多”和“化繁为简”的算法思想。它增长缓慢，是理想的时间复杂度，仅次于常数阶。</p>
<h3 id="6-on-log-n">6. &nbsp; 线性对数阶 <span class="arithmatex">\(O(n \log n)\)</span><a class="headerlink" href="#6-on-log-n" title="Permanent link">&para;</a></h3>
<p>线性对数阶常出现于嵌套循环中，两层循环的时间复杂度分别为 <span class="arithmatex">\(O(\log n)\)</span> 和 <span class="arithmatex">\(O(n)\)</span> 。</p>
<p>主流排序算法的时间复杂度通常为 <span class="arithmatex">\(O(n \log n)\)</span> ，例如快速排序、归并排序、堆排序等。</p>
<p>线性对数阶常出现于嵌套循环中，两层循环的时间复杂度分别为 <span class="arithmatex">\(O(\log n)\)</span> 和 <span class="arithmatex">\(O(n)\)</span> 。相关代码如下：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="14:12"><input checked="checked" id="__tabbed_14_1" name="__tabbed_14" type="radio" /><input id="__tabbed_14_2" name="__tabbed_14" type="radio" /><input id="__tabbed_14_3" name="__tabbed_14" type="radio" /><input id="__tabbed_14_4" name="__tabbed_14" type="radio" /><input id="__tabbed_14_5" name="__tabbed_14" type="radio" /><input id="__tabbed_14_6" name="__tabbed_14" type="radio" /><input id="__tabbed_14_7" name="__tabbed_14" type="radio" /><input id="__tabbed_14_8" name="__tabbed_14" type="radio" /><input id="__tabbed_14_9" name="__tabbed_14" type="radio" /><input id="__tabbed_14_10" name="__tabbed_14" type="radio" /><input id="__tabbed_14_11" name="__tabbed_14" type="radio" /><input id="__tabbed_14_12" name="__tabbed_14" type="radio" /><div class="tabbed-labels"><label for="__tabbed_14_1">Java</label><label for="__tabbed_14_2">C++</label><label for="__tabbed_14_3">Python</label><label for="__tabbed_14_4">Go</label><label for="__tabbed_14_5">JS</label><label for="__tabbed_14_6">TS</label><label for="__tabbed_14_7">C</label><label for="__tabbed_14_8">C#</label><label for="__tabbed_14_9">Swift</label><label for="__tabbed_14_10">Zig</label><label for="__tabbed_14_11">Dart</label><label for="__tabbed_14_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -6025,12 +6028,13 @@ O((n - 1) \frac{n}{2}) = O(n^2)
<p><img alt="线性对数阶的时间复杂度" src="../time_complexity.assets/time_complexity_logarithmic_linear.png" /></p>
<p align="center"> 图：线性对数阶的时间复杂度 </p>
<p>主流排序算法的时间复杂度通常为 <span class="arithmatex">\(O(n \log n)\)</span> ，例如快速排序、归并排序、堆排序等。</p>
<h3 id="7-on">7. &nbsp; 阶乘阶 <span class="arithmatex">\(O(n!)\)</span><a class="headerlink" href="#7-on" title="Permanent link">&para;</a></h3>
<p>阶乘阶对应数学上的“全排列”问题。给定 <span class="arithmatex">\(n\)</span> 个互不重复的元素，求其所有可能的排列方案，方案数量为：</p>
<div class="arithmatex">\[
n! = n \times (n - 1) \times (n - 2) \times \cdots \times 2 \times 1
\]</div>
<p>阶乘通常使用递归实现。例如以下代码，第一层分裂出 <span class="arithmatex">\(n\)</span> 个，第二层分裂出 <span class="arithmatex">\(n - 1\)</span> 个，以此类推，直至第 <span class="arithmatex">\(n\)</span> 层时终止分裂。</p>
<p>阶乘通常使用递归实现。例如在以下代码中，第一层分裂出 <span class="arithmatex">\(n\)</span> 个，第二层分裂出 <span class="arithmatex">\(n - 1\)</span> 个，以此类推，直至第 <span class="arithmatex">\(n\)</span> 层时停止分裂：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="15:12"><input checked="checked" id="__tabbed_15_1" name="__tabbed_15" type="radio" /><input id="__tabbed_15_2" name="__tabbed_15" type="radio" /><input id="__tabbed_15_3" name="__tabbed_15" type="radio" /><input id="__tabbed_15_4" name="__tabbed_15" type="radio" /><input id="__tabbed_15_5" name="__tabbed_15" type="radio" /><input id="__tabbed_15_6" name="__tabbed_15" type="radio" /><input id="__tabbed_15_7" name="__tabbed_15" type="radio" /><input id="__tabbed_15_8" name="__tabbed_15" type="radio" /><input id="__tabbed_15_9" name="__tabbed_15" type="radio" /><input id="__tabbed_15_10" name="__tabbed_15" type="radio" /><input id="__tabbed_15_11" name="__tabbed_15" type="radio" /><input id="__tabbed_15_12" name="__tabbed_15" type="radio" /><div class="tabbed-labels"><label for="__tabbed_15_1">Java</label><label for="__tabbed_15_2">C++</label><label for="__tabbed_15_3">Python</label><label for="__tabbed_15_4">Go</label><label for="__tabbed_15_5">JS</label><label for="__tabbed_15_6">TS</label><label for="__tabbed_15_7">C</label><label for="__tabbed_15_8">C#</label><label for="__tabbed_15_9">Swift</label><label for="__tabbed_15_10">Zig</label><label for="__tabbed_15_11">Dart</label><label for="__tabbed_15_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -6202,14 +6206,14 @@ n! = n \times (n - 1) \times (n - 2) \times \cdots \times 2 \times 1
<p><img alt="阶乘阶的时间复杂度" src="../time_complexity.assets/time_complexity_factorial.png" /></p>
<p align="center"> 图：阶乘阶的时间复杂度 </p>
<p>请注意，因为 <span class="arithmatex">\(n! &gt; 2^n\)</span> ，所以阶乘阶比指数阶增长地更快，在 <span class="arithmatex">\(n\)</span> 较大时也是不可接受的。</p>
<p>请注意，因为 <span class="arithmatex">\(n! &gt; 2^n\)</span> ，所以阶乘阶比指数阶增长得更快，在 <span class="arithmatex">\(n\)</span> 较大时也是不可接受的。</p>
<h2 id="225">2.2.5 &nbsp; 最差、最佳、平均时间复杂度<a class="headerlink" href="#225" title="Permanent link">&para;</a></h2>
<p><strong>算法的时间效率往往不是固定的，而是与输入数据的分布有关</strong>。假设输入一个长度为 <span class="arithmatex">\(n\)</span> 的数组 <code>nums</code> ，其中 <code>nums</code> 由从 <span class="arithmatex">\(1\)</span> 至 <span class="arithmatex">\(n\)</span> 的数字组成，但元素顺序是随机打乱的，任务目标是返回元素 <span class="arithmatex">\(1\)</span> 的索引。我们可以得出以下结论：</p>
<p><strong>算法的时间效率往往不是固定的，而是与输入数据的分布有关</strong>。假设输入一个长度为 <span class="arithmatex">\(n\)</span> 的数组 <code>nums</code> ，其中 <code>nums</code> 由从 <span class="arithmatex">\(1\)</span> 至 <span class="arithmatex">\(n\)</span> 的数字组成，每个数字只出现一次，但元素顺序是随机打乱的，任务目标是返回元素 <span class="arithmatex">\(1\)</span> 的索引。我们可以得出以下结论。</p>
<ul>
<li>当 <code>nums = [?, ?, ..., 1]</code> ，即当末尾元素是 <span class="arithmatex">\(1\)</span> 时，需要完整遍历数组，<strong>达到最差时间复杂度 <span class="arithmatex">\(O(n)\)</span></strong> 。</li>
<li>当 <code>nums = [1, ?, ?, ...]</code> ，即当首个数字为 <span class="arithmatex">\(1\)</span> 时，无论数组多长都不需要继续遍历，<strong>达到最佳时间复杂度 <span class="arithmatex">\(\Omega(1)\)</span></strong> 。</li>
<li>当 <code>nums = [1, ?, ?, ...]</code> ，即当首个元素为 <span class="arithmatex">\(1\)</span> 时，无论数组多长都不需要继续遍历，<strong>达到最佳时间复杂度 <span class="arithmatex">\(\Omega(1)\)</span></strong> 。</li>
</ul>
<p>「最差时间复杂度」对应函数渐近上界，使用大 <span class="arithmatex">\(O\)</span> 记号表示。相应地，「最佳时间复杂度」对应函数渐近下界，用 <span class="arithmatex">\(\Omega\)</span> 记号表示。</p>
<p>「最差时间复杂度」对应函数渐近上界，使用大 <span class="arithmatex">\(O\)</span> 记号表示。相应地，「最佳时间复杂度」对应函数渐近下界，用 <span class="arithmatex">\(\Omega\)</span> 记号表示：</p>
<div class="tabbed-set tabbed-alternate" data-tabs="16:12"><input checked="checked" id="__tabbed_16_1" name="__tabbed_16" type="radio" /><input id="__tabbed_16_2" name="__tabbed_16" type="radio" /><input id="__tabbed_16_3" name="__tabbed_16" type="radio" /><input id="__tabbed_16_4" name="__tabbed_16" type="radio" /><input id="__tabbed_16_5" name="__tabbed_16" type="radio" /><input id="__tabbed_16_6" name="__tabbed_16" type="radio" /><input id="__tabbed_16_7" name="__tabbed_16" type="radio" /><input id="__tabbed_16_8" name="__tabbed_16" type="radio" /><input id="__tabbed_16_9" name="__tabbed_16" type="radio" /><input id="__tabbed_16_10" name="__tabbed_16" type="radio" /><input id="__tabbed_16_11" name="__tabbed_16" type="radio" /><input id="__tabbed_16_12" name="__tabbed_16" type="radio" /><div class="tabbed-labels"><label for="__tabbed_16_1">Java</label><label for="__tabbed_16_2">C++</label><label for="__tabbed_16_3">Python</label><label for="__tabbed_16_4">Go</label><label for="__tabbed_16_5">JS</label><label for="__tabbed_16_6">TS</label><label for="__tabbed_16_7">C</label><label for="__tabbed_16_8">C#</label><label for="__tabbed_16_9">Swift</label><label for="__tabbed_16_10">Zig</label><label for="__tabbed_16_11">Dart</label><label for="__tabbed_16_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -6542,11 +6546,11 @@ n! = n \times (n - 1) \times (n - 2) \times \cdots \times 2 \times 1
</div>
<p>值得说明的是，我们在实际中很少使用「最佳时间复杂度」，因为通常只有在很小概率下才能达到，可能会带来一定的误导性。<strong>而「最差时间复杂度」更为实用，因为它给出了一个效率安全值</strong>，让我们可以放心地使用算法。</p>
<p>从上述示例可以看出，最差或最佳时间复杂度只出现于“特殊的数据分布”，这些情况的出现概率可能很小，并不能真实地反映算法运行效率。相比之下，<strong>「平均时间复杂度」可以体现算法在随机输入数据下的运行效率</strong>，用 <span class="arithmatex">\(\Theta\)</span> 记号来表示。</p>
<p>对于部分算法，我们可以简单地推算出随机数据分布下的平均情况。比如上述示例，由于输入数组是被打乱的，因此元素 <span class="arithmatex">\(1\)</span> 出现在任意索引的概率都是相等的，那么算法的平均循环次数则是数组长度的一半 <span class="arithmatex">\(\frac{n}{2}\)</span> ，平均时间复杂度为 <span class="arithmatex">\(\Theta(\frac{n}{2}) = \Theta(n)\)</span> 。</p>
<p>对于部分算法，我们可以简单地推算出随机数据分布下的平均情况。比如上述示例，由于输入数组是被打乱的，因此元素 <span class="arithmatex">\(1\)</span> 出现在任意索引的概率都是相等的，那么算法的平均循环次数就是数组长度的一半 <span class="arithmatex">\(\frac{n}{2}\)</span> ，平均时间复杂度为 <span class="arithmatex">\(\Theta(\frac{n}{2}) = \Theta(n)\)</span> 。</p>
<p>但对于较为复杂的算法，计算平均时间复杂度往往是比较困难的，因为很难分析出在数据分布下的整体数学期望。在这种情况下，我们通常使用最差时间复杂度作为算法效率的评判标准。</p>
<div class="admonition question">
<p class="admonition-title">为什么很少看到 <span class="arithmatex">\(\Theta\)</span> 符号？</p>
<p>可能由于 <span class="arithmatex">\(O\)</span> 符号过于朗朗上口，我们常常使用它来表示「平均复杂度」，但从严格意义上看，这种做法并不规范。在本书和其他资料中，若遇到类似“平均时间复杂度 <span class="arithmatex">\(O(n)\)</span>”的表述，请将其直接理解为 <span class="arithmatex">\(\Theta(n)\)</span> 。</p>
<p>可能由于 <span class="arithmatex">\(O\)</span> 符号过于朗朗上口，我们常常使用它来表示平均时间复杂度。但从严格意义上看，这种做法并不规范。在本书和其他资料中，若遇到类似“平均时间复杂度 <span class="arithmatex">\(O(n)\)</span>”的表述，请将其直接理解为 <span class="arithmatex">\(\Theta(n)\)</span> 。</p>
</div>
chapter_data_structure/basic_data_types/index.html
+1 -1
View File
@@ -3360,7 +3360,7 @@
<li>整数类型 <code>byte</code> 占用 <span class="arithmatex">\(1\)</span> byte = <span class="arithmatex">\(8\)</span> bits ，可以表示 <span class="arithmatex">\(2^{8}\)</span> 个数字。</li>
<li>整数类型 <code>int</code> 占用 <span class="arithmatex">\(4\)</span> bytes = <span class="arithmatex">\(32\)</span> bits ，可以表示 <span class="arithmatex">\(2^{32}\)</span> 个数字。</li>
</ul>
<p>下表列举了各种基本数据类型的占用空间、取值范围和默认值。此表格无需硬背，大致理解即可，需要时可以通过查表来回忆。</p>
<p>下表列举了各种基本数据类型的占用空间、取值范围和默认值。此表格无须硬背，大致理解即可，需要时可以通过查表来回忆。</p>
<p align="center"> 表：基本数据类型的占用空间和取值范围 </p>
<div class="center-table">
chapter_data_structure/number_encoding/index.html
+1 -1
View File
@@ -3478,7 +3478,7 @@
\]</div>
<p>你可能已经发现，上述的所有计算都是加法运算。这暗示着一个重要事实：<strong>计算机内部的硬件电路主要是基于加法运算设计的</strong>。这是因为加法运算相对于其他运算（比如乘法、除法和减法）来说，硬件实现起来更简单，更容易进行并行化处理，运算速度更快。</p>
<p>请注意，这并不意味着计算机只能做加法。<strong>通过将加法与一些基本逻辑运算结合，计算机能够实现各种其他的数学运算</strong>。例如，计算减法 <span class="arithmatex">\(a - b\)</span> 可以转换为计算加法 <span class="arithmatex">\(a + (-b)\)</span> ；计算乘法和除法可以转换为计算多次加法或减法。</p>
<p>现在我们可以总结出计算机使用补码的原因：基于补码表示，计算机可以用同样的电路和操作来处理正数和负数的加法，不需要设计特殊的硬件电路来处理减法，并且无需特别处理正负零的歧义问题。这大大简化了硬件设计，提高了运算效率。</p>
<p>现在我们可以总结出计算机使用补码的原因：基于补码表示，计算机可以用同样的电路和操作来处理正数和负数的加法，不需要设计特殊的硬件电路来处理减法，并且无须特别处理正负零的歧义问题。这大大简化了硬件设计，提高了运算效率。</p>
<p>补码的设计非常精妙，因篇幅关系我们就先介绍到这里，建议有兴趣的读者进一步深度了解。</p>
<h2 id="332">3.3.2 &nbsp; 浮点数编码<a class="headerlink" href="#332" title="Permanent link">&para;</a></h2>
<p>细心的你可能会发现：<code>int</code> 和 <code>float</code> 长度相同，都是 4 bytes，但为什么 <code>float</code> 的取值范围远大于 <code>int</code> ？这非常反直觉，因为按理说 <code>float</code> 需要表示小数，取值范围应该变小才对。</p>
chapter_divide_and_conquer/binary_search_recur/index.html
+1 -1
View File
@@ -3420,7 +3420,7 @@
<ul>
<li><strong>问题可以被分解</strong>：二分查找递归地将原问题（在数组中进行查找）分解为子问题（在数组的一半中进行查找），这是通过比较中间元素和目标元素来实现的。</li>
<li><strong>子问题是独立的</strong>：在二分查找中，每轮只处理一个子问题，它不受另外子问题的影响。</li>
<li><strong>子问题的解无需合并</strong>：二分查找旨在查找一个特定元素，因此不需要将子问题的解进行合并。当子问题得到解决时，原问题也会同时得到解决。</li>
<li><strong>子问题的解无须合并</strong>：二分查找旨在查找一个特定元素，因此不需要将子问题的解进行合并。当子问题得到解决时，原问题也会同时得到解决。</li>
</ul>
<p>分治能够提升搜索效率，本质上是因为暴力搜索每轮只能排除一个选项，<strong>而分治搜索每轮可以排除一半选项</strong>。</p>
<h3 id="1">1. &nbsp; 基于分治实现二分<a class="headerlink" href="#1" title="Permanent link">&para;</a></h3>
chapter_divide_and_conquer/summary/index.html
+1 -1
View File
@@ -3350,7 +3350,7 @@
<li>分治算法是一种常见的算法设计策略，包括分（划分）和治（合并）两个阶段，通常基于递归实现。</li>
<li>判断是否是分治算法问题的依据包括：问题能否被分解、子问题是否独立、子问题是否可以被合并。</li>
<li>归并排序是分治策略的典型应用，其递归地将数组划分为等长的两个子数组，直到只剩一个元素时开始逐层合并，从而完成排序。</li>
<li>引入分治策略往往可以带来算法效率的提升。一方面，分治策略减少了计算操作数量；另一方面，分治后有利于系统的并行优化。</li>
<li>引入分治策略往往可以带来算法效率的提升。一方面，分治策略减少了操作数量；另一方面，分治后有利于系统的并行优化。</li>
<li>分治既可以解决许多算法问题，也广泛应用于数据结构与算法设计中，处处可见其身影。</li>
<li>相较于暴力搜索，自适应搜索效率更高。时间复杂度为 <span class="arithmatex">\(O(\log n)\)</span> 的搜索算法通常都是基于分治策略实现的。</li>
<li>二分查找是分治思想的另一个典型应用，它不包含将子问题的解进行合并的步骤。我们可以通过递归分治实现二分查找。</li>
chapter_dynamic_programming/dp_problem_features/index.html
+1 -1
View File
@@ -3795,7 +3795,7 @@ dp[i] = \min(dp[i-1], dp[i-2]) + cost[i]
</div>
<h2 id="1422">14.2.2 &nbsp; 无后效性<a class="headerlink" href="#1422" title="Permanent link">&para;</a></h2>
<p>「无后效性」是动态规划能够有效解决问题的重要特性之一，定义为：<strong>给定一个确定的状态，它的未来发展只与当前状态有关，而与当前状态过去所经历过的所有状态无关</strong>。</p>
<p>以爬楼梯问题为例，给定状态 <span class="arithmatex">\(i\)</span> ，它会发展出状态 <span class="arithmatex">\(i+1\)</span> 和状态 <span class="arithmatex">\(i+2\)</span> ，分别对应跳 <span class="arithmatex">\(1\)</span> 步和跳 <span class="arithmatex">\(2\)</span> 步。在做出这两种选择时，我们无需考虑状态 <span class="arithmatex">\(i\)</span> 之前的状态，它们对状态 <span class="arithmatex">\(i\)</span> 的未来没有影响。</p>
<p>以爬楼梯问题为例，给定状态 <span class="arithmatex">\(i\)</span> ，它会发展出状态 <span class="arithmatex">\(i+1\)</span> 和状态 <span class="arithmatex">\(i+2\)</span> ，分别对应跳 <span class="arithmatex">\(1\)</span> 步和跳 <span class="arithmatex">\(2\)</span> 步。在做出这两种选择时，我们无须考虑状态 <span class="arithmatex">\(i\)</span> 之前的状态，它们对状态 <span class="arithmatex">\(i\)</span> 的未来没有影响。</p>
<p>然而，如果我们向爬楼梯问题添加一个约束，情况就不一样了。</p>
<div class="admonition question">
<p class="admonition-title">带约束爬楼梯</p>
chapter_dynamic_programming/edit_distance_problem/index.html
+1 -1
View File
@@ -3475,7 +3475,7 @@
<div class="arithmatex">\[
dp[i, j] = \min(dp[i, j-1], dp[i-1, j], dp[i-1, j-1]) + 1
\]</div>
<p>请注意，<strong>当 <span class="arithmatex">\(s[i-1]\)</span> 和 <span class="arithmatex">\(t[j-1]\)</span> 相同时，无需编辑当前字符</strong>，这种情况下的状态转移方程为：</p>
<p>请注意，<strong>当 <span class="arithmatex">\(s[i-1]\)</span> 和 <span class="arithmatex">\(t[j-1]\)</span> 相同时，无须编辑当前字符</strong>，这种情况下的状态转移方程为：</p>
<div class="arithmatex">\[
dp[i, j] = dp[i-1, j-1]
\]</div>
chapter_dynamic_programming/intro_to_dynamic_programming/index.html
+2 -2
View File
@@ -4287,7 +4287,7 @@ dp[i] = dp[i-1] + dp[i-2]
<h2 id="1413">14.1.3 &nbsp; 方法三：动态规划<a class="headerlink" href="#1413" title="Permanent link">&para;</a></h2>
<p><strong>记忆化搜索是一种“从顶至底”的方法</strong>：我们从原问题（根节点）开始，递归地将较大子问题分解为较小子问题，直至解已知的最小子问题（叶节点）。之后，通过回溯将子问题的解逐层收集，构建出原问题的解。</p>
<p>与之相反，<strong>动态规划是一种“从底至顶”的方法</strong>：从最小子问题的解开始，迭代地构建更大子问题的解，直至得到原问题的解。</p>
<p>由于动态规划不包含回溯过程，因此只需使用循环迭代实现，无需使用递归。在以下代码中，我们初始化一个数组 <code>dp</code> 来存储子问题的解，它起到了记忆化搜索中数组 <code>mem</code> 相同的记录作用。</p>
<p>由于动态规划不包含回溯过程，因此只需使用循环迭代实现，无须使用递归。在以下代码中，我们初始化一个数组 <code>dp</code> 来存储子问题的解，它起到了记忆化搜索中数组 <code>mem</code> 相同的记录作用。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="4:12"><input checked="checked" id="__tabbed_4_1" name="__tabbed_4" type="radio" /><input id="__tabbed_4_2" name="__tabbed_4" type="radio" /><input id="__tabbed_4_3" name="__tabbed_4" type="radio" /><input id="__tabbed_4_4" name="__tabbed_4" type="radio" /><input id="__tabbed_4_5" name="__tabbed_4" type="radio" /><input id="__tabbed_4_6" name="__tabbed_4" type="radio" /><input id="__tabbed_4_7" name="__tabbed_4" type="radio" /><input id="__tabbed_4_8" name="__tabbed_4" type="radio" /><input id="__tabbed_4_9" name="__tabbed_4" type="radio" /><input id="__tabbed_4_10" name="__tabbed_4" type="radio" /><input id="__tabbed_4_11" name="__tabbed_4" type="radio" /><input id="__tabbed_4_12" name="__tabbed_4" type="radio" /><div class="tabbed-labels"><label for="__tabbed_4_1">Java</label><label for="__tabbed_4_2">C++</label><label for="__tabbed_4_3">Python</label><label for="__tabbed_4_4">Go</label><label for="__tabbed_4_5">JS</label><label for="__tabbed_4_6">TS</label><label for="__tabbed_4_7">C</label><label for="__tabbed_4_8">C#</label><label for="__tabbed_4_9">Swift</label><label for="__tabbed_4_10">Zig</label><label for="__tabbed_4_11">Dart</label><label for="__tabbed_4_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -4503,7 +4503,7 @@ dp[i] = dp[i-1] + dp[i-2]
<p align="center"> 图：爬楼梯的动态规划过程 </p>
<h2 id="1414">14.1.4 &nbsp; 状态压缩<a class="headerlink" href="#1414" title="Permanent link">&para;</a></h2>
<p>细心的你可能发现，<strong>由于 <span class="arithmatex">\(dp[i]\)</span> 只与 <span class="arithmatex">\(dp[i-1]\)</span> 和 <span class="arithmatex">\(dp[i-2]\)</span> 有关，因此我们无需使用一个数组 <code>dp</code> 来存储所有子问题的解</strong>，而只需两个变量滚动前进即可。</p>
<p>细心的你可能发现，<strong>由于 <span class="arithmatex">\(dp[i]\)</span> 只与 <span class="arithmatex">\(dp[i-1]\)</span> 和 <span class="arithmatex">\(dp[i-2]\)</span> 有关，因此我们无须使用一个数组 <code>dp</code> 来存储所有子问题的解</strong>，而只需两个变量滚动前进即可。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="5:12"><input checked="checked" id="__tabbed_5_1" name="__tabbed_5" type="radio" /><input id="__tabbed_5_2" name="__tabbed_5" type="radio" /><input id="__tabbed_5_3" name="__tabbed_5" type="radio" /><input id="__tabbed_5_4" name="__tabbed_5" type="radio" /><input id="__tabbed_5_5" name="__tabbed_5" type="radio" /><input id="__tabbed_5_6" name="__tabbed_5" type="radio" /><input id="__tabbed_5_7" name="__tabbed_5" type="radio" /><input id="__tabbed_5_8" name="__tabbed_5" type="radio" /><input id="__tabbed_5_9" name="__tabbed_5" type="radio" /><input id="__tabbed_5_10" name="__tabbed_5" type="radio" /><input id="__tabbed_5_11" name="__tabbed_5" type="radio" /><input id="__tabbed_5_12" name="__tabbed_5" type="radio" /><div class="tabbed-labels"><label for="__tabbed_5_1">Java</label><label for="__tabbed_5_2">C++</label><label for="__tabbed_5_3">Python</label><label for="__tabbed_5_4">Go</label><label for="__tabbed_5_5">JS</label><label for="__tabbed_5_6">TS</label><label for="__tabbed_5_7">C</label><label for="__tabbed_5_8">C#</label><label for="__tabbed_5_9">Swift</label><label for="__tabbed_5_10">Zig</label><label for="__tabbed_5_11">Dart</label><label for="__tabbed_5_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
chapter_dynamic_programming/summary/index.html
+1 -1
View File
@@ -3366,7 +3366,7 @@
<p><strong>编辑距离问题</strong></p>
<ul>
<li>编辑距离（Levenshtein 距离）用于衡量两个字符串之间的相似度，其定义为从一个字符串到另一个字符串的最小编辑步数，编辑操作包括添加、删除、替换。</li>
<li>编辑距离问题的状态定义为将 <span class="arithmatex">\(s\)</span> 的前 <span class="arithmatex">\(i\)</span> 个字符更改为 <span class="arithmatex">\(t\)</span> 的前 <span class="arithmatex">\(j\)</span> 个字符所需的最少编辑步数。当 <span class="arithmatex">\(s[i] \ne t[j]\)</span> 时，具有三种决策：添加、删除、替换，它们都有相应的剩余子问题。据此便可以找出最优子结构与构建状态转移方程。而当 <span class="arithmatex">\(s[i] = t[j]\)</span> 时，无需编辑当前字符。</li>
<li>编辑距离问题的状态定义为将 <span class="arithmatex">\(s\)</span> 的前 <span class="arithmatex">\(i\)</span> 个字符更改为 <span class="arithmatex">\(t\)</span> 的前 <span class="arithmatex">\(j\)</span> 个字符所需的最少编辑步数。当 <span class="arithmatex">\(s[i] \ne t[j]\)</span> 时，具有三种决策：添加、删除、替换，它们都有相应的剩余子问题。据此便可以找出最优子结构与构建状态转移方程。而当 <span class="arithmatex">\(s[i] = t[j]\)</span> 时，无须编辑当前字符。</li>
<li>在编辑距离中，状态依赖于其正上方、正左方、左上方的状态，因此状态压缩后正序或倒序遍历都无法正确地进行状态转移。为此，我们利用一个变量暂存左上方状态，从而转化到与完全背包等价的情况，可以在状态压缩后进行正序遍历。</li>
</ul>
chapter_dynamic_programming/unbounded_knapsack_problem/index.html
+1 -1
View File
@@ -4684,7 +4684,7 @@ dp[i, a] = \min(dp[i-1, a], dp[i, a - coins[i-1]] + 1)
<div class="arithmatex">\[
dp[i, a] = dp[i-1, a] + dp[i, a - coins[i-1]]
\]</div>
<p>当目标金额为 <span class="arithmatex">\(0\)</span> 时，无需选择任何硬币即可凑出目标金额，因此应将首列所有 <span class="arithmatex">\(dp[i, 0]\)</span> 都初始化为 <span class="arithmatex">\(1\)</span> 。当无硬币时，无法凑出任何 <span class="arithmatex">\(&gt;0\)</span> 的目标金额，因此首行所有 <span class="arithmatex">\(dp[0, a]\)</span> 都等于 <span class="arithmatex">\(0\)</span> 。</p>
<p>当目标金额为 <span class="arithmatex">\(0\)</span> 时，无须选择任何硬币即可凑出目标金额，因此应将首列所有 <span class="arithmatex">\(dp[i, 0]\)</span> 都初始化为 <span class="arithmatex">\(1\)</span> 。当无硬币时，无法凑出任何 <span class="arithmatex">\(&gt;0\)</span> 的目标金额，因此首行所有 <span class="arithmatex">\(dp[0, a]\)</span> 都等于 <span class="arithmatex">\(0\)</span> 。</p>
<h3 id="2_2">2. &nbsp; 代码实现<a class="headerlink" href="#2_2" title="Permanent link">&para;</a></h3>
<div class="tabbed-set tabbed-alternate" data-tabs="7:12"><input checked="checked" id="__tabbed_7_1" name="__tabbed_7" type="radio" /><input id="__tabbed_7_2" name="__tabbed_7" type="radio" /><input id="__tabbed_7_3" name="__tabbed_7" type="radio" /><input id="__tabbed_7_4" name="__tabbed_7" type="radio" /><input id="__tabbed_7_5" name="__tabbed_7" type="radio" /><input id="__tabbed_7_6" name="__tabbed_7" type="radio" /><input id="__tabbed_7_7" name="__tabbed_7" type="radio" /><input id="__tabbed_7_8" name="__tabbed_7" type="radio" /><input id="__tabbed_7_9" name="__tabbed_7" type="radio" /><input id="__tabbed_7_10" name="__tabbed_7" type="radio" /><input id="__tabbed_7_11" name="__tabbed_7" type="radio" /><input id="__tabbed_7_12" name="__tabbed_7" type="radio" /><div class="tabbed-labels"><label for="__tabbed_7_1">Java</label><label for="__tabbed_7_2">C++</label><label for="__tabbed_7_3">Python</label><label for="__tabbed_7_4">Go</label><label for="__tabbed_7_5">JS</label><label for="__tabbed_7_6">TS</label><label for="__tabbed_7_7">C</label><label for="__tabbed_7_8">C#</label><label for="__tabbed_7_9">Swift</label><label for="__tabbed_7_10">Zig</label><label for="__tabbed_7_11">Dart</label><label for="__tabbed_7_12">Rust</label></div>
<div class="tabbed-content">
chapter_graph/graph_operations/index.html
+1 -1
View File
@@ -4561,7 +4561,7 @@
<ul>
<li>如果我们选择通过顶点值来区分不同顶点，那么值重复的顶点将无法被区分。</li>
<li>如果类似邻接矩阵那样，使用顶点列表索引来区分不同顶点。那么，假设我们想要删除索引为 <span class="arithmatex">\(i\)</span> 的顶点，则需要遍历整个邻接表，将其中 <span class="arithmatex">\(&gt; i\)</span> 的索引全部减 <span class="arithmatex">\(1\)</span> ，这样操作效率较低。</li>
<li>因此我们考虑引入顶点类 <code>Vertex</code> ，使得每个顶点都是唯一的对象，此时删除顶点时就无需改动其余顶点了。</li>
<li>因此我们考虑引入顶点类 <code>Vertex</code> ，使得每个顶点都是唯一的对象，此时删除顶点时就无须改动其余顶点了。</li>
</ul>
<div class="tabbed-set tabbed-alternate" data-tabs="4:12"><input checked="checked" id="__tabbed_4_1" name="__tabbed_4" type="radio" /><input id="__tabbed_4_2" name="__tabbed_4" type="radio" /><input id="__tabbed_4_3" name="__tabbed_4" type="radio" /><input id="__tabbed_4_4" name="__tabbed_4" type="radio" /><input id="__tabbed_4_5" name="__tabbed_4" type="radio" /><input id="__tabbed_4_6" name="__tabbed_4" type="radio" /><input id="__tabbed_4_7" name="__tabbed_4" type="radio" /><input id="__tabbed_4_8" name="__tabbed_4" type="radio" /><input id="__tabbed_4_9" name="__tabbed_4" type="radio" /><input id="__tabbed_4_10" name="__tabbed_4" type="radio" /><input id="__tabbed_4_11" name="__tabbed_4" type="radio" /><input id="__tabbed_4_12" name="__tabbed_4" type="radio" /><div class="tabbed-labels"><label for="__tabbed_4_1">Java</label><label for="__tabbed_4_2">C++</label><label for="__tabbed_4_3">Python</label><label for="__tabbed_4_4">Go</label><label for="__tabbed_4_5">JS</label><label for="__tabbed_4_6">TS</label><label for="__tabbed_4_7">C</label><label for="__tabbed_4_8">C#</label><label for="__tabbed_4_9">Swift</label><label for="__tabbed_4_10">Zig</label><label for="__tabbed_4_11">Dart</label><label for="__tabbed_4_12">Rust</label></div>
<div class="tabbed-content">
chapter_greedy/max_product_cutting_problem/index.html
+1 -1
View File
@@ -3478,7 +3478,7 @@ n &amp; \geq 4
<li>当余数为 <span class="arithmatex">\(1\)</span> 时，由于 <span class="arithmatex">\(2 \times 2 &gt; 1 \times 3\)</span> ，因此应将最后一个 <span class="arithmatex">\(3\)</span> 替换为 <span class="arithmatex">\(2\)</span> 。</li>
</ol>
<h3 id="2">2. &nbsp; 代码实现<a class="headerlink" href="#2" title="Permanent link">&para;</a></h3>
<p>在代码中，我们无需通过循环来切分整数，而可以利用向下整除运算得到 <span class="arithmatex">\(3\)</span> 的个数 <span class="arithmatex">\(a\)</span> ，用取模运算得到余数 <span class="arithmatex">\(b\)</span> ，此时有：</p>
<p>在代码中，我们无须通过循环来切分整数，而可以利用向下整除运算得到 <span class="arithmatex">\(3\)</span> 的个数 <span class="arithmatex">\(a\)</span> ，用取模运算得到余数 <span class="arithmatex">\(b\)</span> ，此时有：</p>
<div class="arithmatex">\[
n = 3 a + b
\]</div>
chapter_heap/build_heap/index.html
+1 -1
View File
@@ -3432,7 +3432,7 @@
<p>设元素数量为 <span class="arithmatex">\(n\)</span> ，入堆操作使用 <span class="arithmatex">\(O(\log{n})\)</span> 时间，因此将所有元素入堆的时间复杂度为 <span class="arithmatex">\(O(n \log n)\)</span> 。</p>
<h2 id="822">8.2.2 &nbsp; 基于堆化操作实现<a class="headerlink" href="#822" title="Permanent link">&para;</a></h2>
<p>有趣的是，存在一种更高效的建堆方法，其时间复杂度可以达到 <span class="arithmatex">\(O(n)\)</span> 。我们先将列表所有元素原封不动添加到堆中，然后倒序遍历该堆，依次对每个节点执行“从顶至底堆化”。</p>
<p>请注意，因为叶节点没有子节点，所以无需堆化。在代码实现中，我们从最后一个节点的父节点开始进行堆化。</p>
<p>请注意，因为叶节点没有子节点，所以无须堆化。在代码实现中，我们从最后一个节点的父节点开始进行堆化。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="1:12"><input checked="checked" id="__tabbed_1_1" name="__tabbed_1" type="radio" /><input id="__tabbed_1_2" name="__tabbed_1" type="radio" /><input id="__tabbed_1_3" name="__tabbed_1" type="radio" /><input id="__tabbed_1_4" name="__tabbed_1" type="radio" /><input id="__tabbed_1_5" name="__tabbed_1" type="radio" /><input id="__tabbed_1_6" name="__tabbed_1" type="radio" /><input id="__tabbed_1_7" name="__tabbed_1" type="radio" /><input id="__tabbed_1_8" name="__tabbed_1" type="radio" /><input id="__tabbed_1_9" name="__tabbed_1" type="radio" /><input id="__tabbed_1_10" name="__tabbed_1" type="radio" /><input id="__tabbed_1_11" name="__tabbed_1" type="radio" /><input id="__tabbed_1_12" name="__tabbed_1" type="radio" /><div class="tabbed-labels"><label for="__tabbed_1_1">Java</label><label for="__tabbed_1_2">C++</label><label for="__tabbed_1_3">Python</label><label for="__tabbed_1_4">Go</label><label for="__tabbed_1_5">JS</label><label for="__tabbed_1_6">TS</label><label for="__tabbed_1_7">C</label><label for="__tabbed_1_8">C#</label><label for="__tabbed_1_9">Swift</label><label for="__tabbed_1_10">Zig</label><label for="__tabbed_1_11">Dart</label><label for="__tabbed_1_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
chapter_heap/heap/index.html
+26 -26
View File
@@ -4119,7 +4119,7 @@
</div>
<h3 id="3">3. &nbsp; 元素入堆<a class="headerlink" href="#3" title="Permanent link">&para;</a></h3>
<p>给定元素 <code>val</code> ，我们首先将其添加到堆底。添加之后，由于 val 可能大于堆中其他元素，堆的成立条件可能已被破坏。因此，<strong>需要修复从插入节点到根节点的路径上的各个节点</strong>，这个操作被称为「堆化 Heapify」。</p>
<p>考虑从入堆节点开始，<strong>从底至顶执行堆化</strong>。具体来说，我们比较插入节点与其父节点的值，如果插入节点更大，则将它们交换。然后继续执行此操作，从底至顶修复堆中的各个节点，直至越过根节点或遇到无需交换的节点时结束。</p>
<p>考虑从入堆节点开始，<strong>从底至顶执行堆化</strong>。具体来说，我们比较插入节点与其父节点的值，如果插入节点更大，则将它们交换。然后继续执行此操作，从底至顶修复堆中的各个节点，直至越过根节点或遇到无须交换的节点时结束。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="4:9"><input checked="checked" id="__tabbed_4_1" name="__tabbed_4" type="radio" /><input id="__tabbed_4_2" name="__tabbed_4" type="radio" /><input id="__tabbed_4_3" name="__tabbed_4" type="radio" /><input id="__tabbed_4_4" name="__tabbed_4" type="radio" /><input id="__tabbed_4_5" name="__tabbed_4" type="radio" /><input id="__tabbed_4_6" name="__tabbed_4" type="radio" /><input id="__tabbed_4_7" name="__tabbed_4" type="radio" /><input id="__tabbed_4_8" name="__tabbed_4" type="radio" /><input id="__tabbed_4_9" name="__tabbed_4" type="radio" /><div class="tabbed-labels"><label for="__tabbed_4_1">&lt;1&gt;</label><label for="__tabbed_4_2">&lt;2&gt;</label><label for="__tabbed_4_3">&lt;3&gt;</label><label for="__tabbed_4_4">&lt;4&gt;</label><label for="__tabbed_4_5">&lt;5&gt;</label><label for="__tabbed_4_6">&lt;6&gt;</label><label for="__tabbed_4_7">&lt;7&gt;</label><label for="__tabbed_4_8">&lt;8&gt;</label><label for="__tabbed_4_9">&lt;9&gt;</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -4170,7 +4170,7 @@
<a id="__codelineno-36-11" name="__codelineno-36-11" href="#__codelineno-36-11"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="kc">true</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-36-12" name="__codelineno-36-12" href="#__codelineno-36-12"></a><span class="w"> </span><span class="c1">// 获取节点 i 的父节点</span>
<a id="__codelineno-36-13" name="__codelineno-36-13" href="#__codelineno-36-13"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">p</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">parent</span><span class="p">(</span><span class="n">i</span><span class="p">);</span>
<a id="__codelineno-36-14" name="__codelineno-36-14" href="#__codelineno-36-14"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无需修复”时，结束堆化</span>
<a id="__codelineno-36-14" name="__codelineno-36-14" href="#__codelineno-36-14"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无须修复”时，结束堆化</span>
<a id="__codelineno-36-15" name="__codelineno-36-15" href="#__codelineno-36-15"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">p</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="n">maxHeap</span><span class="p">.</span><span class="na">get</span><span class="p">(</span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="o">&lt;=</span><span class="w"> </span><span class="n">maxHeap</span><span class="p">.</span><span class="na">get</span><span class="p">(</span><span class="n">p</span><span class="p">))</span>
<a id="__codelineno-36-16" name="__codelineno-36-16" href="#__codelineno-36-16"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-36-17" name="__codelineno-36-17" href="#__codelineno-36-17"></a><span class="w"> </span><span class="c1">// 交换两节点</span>
@@ -4195,7 +4195,7 @@
<a id="__codelineno-37-11" name="__codelineno-37-11" href="#__codelineno-37-11"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="nb">true</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-37-12" name="__codelineno-37-12" href="#__codelineno-37-12"></a><span class="w"> </span><span class="c1">// 获取节点 i 的父节点</span>
<a id="__codelineno-37-13" name="__codelineno-37-13" href="#__codelineno-37-13"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">p</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">parent</span><span class="p">(</span><span class="n">i</span><span class="p">);</span>
<a id="__codelineno-37-14" name="__codelineno-37-14" href="#__codelineno-37-14"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无需修复”时，结束堆化</span>
<a id="__codelineno-37-14" name="__codelineno-37-14" href="#__codelineno-37-14"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无须修复”时，结束堆化</span>
<a id="__codelineno-37-15" name="__codelineno-37-15" href="#__codelineno-37-15"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">p</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="n">maxHeap</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">&lt;=</span><span class="w"> </span><span class="n">maxHeap</span><span class="p">[</span><span class="n">p</span><span class="p">])</span>
<a id="__codelineno-37-16" name="__codelineno-37-16" href="#__codelineno-37-16"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-37-17" name="__codelineno-37-17" href="#__codelineno-37-17"></a><span class="w"> </span><span class="c1">// 交换两节点</span>
@@ -4219,7 +4219,7 @@
<a id="__codelineno-38-10" name="__codelineno-38-10" href="#__codelineno-38-10"></a> <span class="k">while</span> <span class="kc">True</span><span class="p">:</span>
<a id="__codelineno-38-11" name="__codelineno-38-11" href="#__codelineno-38-11"></a> <span class="c1"># 获取节点 i 的父节点</span>
<a id="__codelineno-38-12" name="__codelineno-38-12" href="#__codelineno-38-12"></a> <span class="n">p</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">parent</span><span class="p">(</span><span class="n">i</span><span class="p">)</span>
<a id="__codelineno-38-13" name="__codelineno-38-13" href="#__codelineno-38-13"></a> <span class="c1"># 当“越过根节点”或“节点无需修复”时，结束堆化</span>
<a id="__codelineno-38-13" name="__codelineno-38-13" href="#__codelineno-38-13"></a> <span class="c1"># 当“越过根节点”或“节点无须修复”时，结束堆化</span>
<a id="__codelineno-38-14" name="__codelineno-38-14" href="#__codelineno-38-14"></a> <span class="k">if</span> <span class="n">p</span> <span class="o">&lt;</span> <span class="mi">0</span> <span class="ow">or</span> <span class="bp">self</span><span class="o">.</span><span class="n">max_heap</span><span class="p">[</span><span class="n">i</span><span class="p">]</span> <span class="o">&lt;=</span> <span class="bp">self</span><span class="o">.</span><span class="n">max_heap</span><span class="p">[</span><span class="n">p</span><span class="p">]:</span>
<a id="__codelineno-38-15" name="__codelineno-38-15" href="#__codelineno-38-15"></a> <span class="k">break</span>
<a id="__codelineno-38-16" name="__codelineno-38-16" href="#__codelineno-38-16"></a> <span class="c1"># 交换两节点</span>
@@ -4242,7 +4242,7 @@
<a id="__codelineno-39-11" name="__codelineno-39-11" href="#__codelineno-39-11"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="kc">true</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-39-12" name="__codelineno-39-12" href="#__codelineno-39-12"></a><span class="w"> </span><span class="c1">// 获取节点 i 的父节点</span>
<a id="__codelineno-39-13" name="__codelineno-39-13" href="#__codelineno-39-13"></a><span class="w"> </span><span class="nx">p</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">h</span><span class="p">.</span><span class="nx">parent</span><span class="p">(</span><span class="nx">i</span><span class="p">)</span>
<a id="__codelineno-39-14" name="__codelineno-39-14" href="#__codelineno-39-14"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无需修复”时，结束堆化</span>
<a id="__codelineno-39-14" name="__codelineno-39-14" href="#__codelineno-39-14"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无须修复”时，结束堆化</span>
<a id="__codelineno-39-15" name="__codelineno-39-15" href="#__codelineno-39-15"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">p</span><span class="w"> </span><span class="p">&lt;</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="nx">h</span><span class="p">.</span><span class="nx">data</span><span class="p">[</span><span class="nx">i</span><span class="p">].(</span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="o">&lt;=</span><span class="w"> </span><span class="nx">h</span><span class="p">.</span><span class="nx">data</span><span class="p">[</span><span class="nx">p</span><span class="p">].(</span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-39-16" name="__codelineno-39-16" href="#__codelineno-39-16"></a><span class="w"> </span><span class="k">break</span>
<a id="__codelineno-39-17" name="__codelineno-39-17" href="#__codelineno-39-17"></a><span class="w"> </span><span class="p">}</span>
@@ -4268,7 +4268,7 @@
<a id="__codelineno-40-11" name="__codelineno-40-11" href="#__codelineno-40-11"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="kc">true</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-40-12" name="__codelineno-40-12" href="#__codelineno-40-12"></a><span class="w"> </span><span class="c1">// 获取节点 i 的父节点</span>
<a id="__codelineno-40-13" name="__codelineno-40-13" href="#__codelineno-40-13"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">p</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">parent</span><span class="p">(</span><span class="nx">i</span><span class="p">);</span>
<a id="__codelineno-40-14" name="__codelineno-40-14" href="#__codelineno-40-14"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无需修复”时，结束堆化</span>
<a id="__codelineno-40-14" name="__codelineno-40-14" href="#__codelineno-40-14"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无须修复”时，结束堆化</span>
<a id="__codelineno-40-15" name="__codelineno-40-15" href="#__codelineno-40-15"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">p</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="mf">0</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">maxHeap</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">&lt;=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">maxHeap</span><span class="p">[</span><span class="nx">p</span><span class="p">])</span><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-40-16" name="__codelineno-40-16" href="#__codelineno-40-16"></a><span class="w"> </span><span class="c1">// 交换两节点</span>
<a id="__codelineno-40-17" name="__codelineno-40-17" href="#__codelineno-40-17"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">swap</span><span class="p">(</span><span class="nx">i</span><span class="p">,</span><span class="w"> </span><span class="nx">p</span><span class="p">);</span>
@@ -4292,7 +4292,7 @@
<a id="__codelineno-41-11" name="__codelineno-41-11" href="#__codelineno-41-11"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="kc">true</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-41-12" name="__codelineno-41-12" href="#__codelineno-41-12"></a><span class="w"> </span><span class="c1">// 获取节点 i 的父节点</span>
<a id="__codelineno-41-13" name="__codelineno-41-13" href="#__codelineno-41-13"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">p</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">parent</span><span class="p">(</span><span class="nx">i</span><span class="p">);</span>
<a id="__codelineno-41-14" name="__codelineno-41-14" href="#__codelineno-41-14"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无需修复”时，结束堆化</span>
<a id="__codelineno-41-14" name="__codelineno-41-14" href="#__codelineno-41-14"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无须修复”时，结束堆化</span>
<a id="__codelineno-41-15" name="__codelineno-41-15" href="#__codelineno-41-15"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">p</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="mf">0</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">maxHeap</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">&lt;=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">maxHeap</span><span class="p">[</span><span class="nx">p</span><span class="p">])</span><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-41-16" name="__codelineno-41-16" href="#__codelineno-41-16"></a><span class="w"> </span><span class="c1">// 交换两节点</span>
<a id="__codelineno-41-17" name="__codelineno-41-17" href="#__codelineno-41-17"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">swap</span><span class="p">(</span><span class="nx">i</span><span class="p">,</span><span class="w"> </span><span class="nx">p</span><span class="p">);</span>
@@ -4323,7 +4323,7 @@
<a id="__codelineno-42-18" name="__codelineno-42-18" href="#__codelineno-42-18"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="nb">true</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-42-19" name="__codelineno-42-19" href="#__codelineno-42-19"></a><span class="w"> </span><span class="c1">// 获取节点 i 的父节点</span>
<a id="__codelineno-42-20" name="__codelineno-42-20" href="#__codelineno-42-20"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">p</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">parent</span><span class="p">(</span><span class="n">h</span><span class="p">,</span><span class="w"> </span><span class="n">i</span><span class="p">);</span>
<a id="__codelineno-42-21" name="__codelineno-42-21" href="#__codelineno-42-21"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无需修复”时，结束堆化</span>
<a id="__codelineno-42-21" name="__codelineno-42-21" href="#__codelineno-42-21"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无须修复”时，结束堆化</span>
<a id="__codelineno-42-22" name="__codelineno-42-22" href="#__codelineno-42-22"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">p</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="n">h</span><span class="o">-&gt;</span><span class="n">data</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">&lt;=</span><span class="w"> </span><span class="n">h</span><span class="o">-&gt;</span><span class="n">data</span><span class="p">[</span><span class="n">p</span><span class="p">])</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-42-23" name="__codelineno-42-23" href="#__codelineno-42-23"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-42-24" name="__codelineno-42-24" href="#__codelineno-42-24"></a><span class="w"> </span><span class="p">}</span>
@@ -4349,7 +4349,7 @@
<a id="__codelineno-43-11" name="__codelineno-43-11" href="#__codelineno-43-11"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="k">true</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-43-12" name="__codelineno-43-12" href="#__codelineno-43-12"></a><span class="w"> </span><span class="c1">// 获取节点 i 的父节点</span>
<a id="__codelineno-43-13" name="__codelineno-43-13" href="#__codelineno-43-13"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">p</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">parent</span><span class="p">(</span><span class="n">i</span><span class="p">);</span>
<a id="__codelineno-43-14" name="__codelineno-43-14" href="#__codelineno-43-14"></a><span class="w"> </span><span class="c1">// 若“越过根节点”或“节点无需修复”，则结束堆化</span>
<a id="__codelineno-43-14" name="__codelineno-43-14" href="#__codelineno-43-14"></a><span class="w"> </span><span class="c1">// 若“越过根节点”或“节点无须修复”，则结束堆化</span>
<a id="__codelineno-43-15" name="__codelineno-43-15" href="#__codelineno-43-15"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">p</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="m">0</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="n">maxHeap</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">&lt;=</span><span class="w"> </span><span class="n">maxHeap</span><span class="p">[</span><span class="n">p</span><span class="p">])</span>
<a id="__codelineno-43-16" name="__codelineno-43-16" href="#__codelineno-43-16"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-43-17" name="__codelineno-43-17" href="#__codelineno-43-17"></a><span class="w"> </span><span class="c1">// 交换两节点</span>
@@ -4375,7 +4375,7 @@
<a id="__codelineno-44-12" name="__codelineno-44-12" href="#__codelineno-44-12"></a> <span class="k">while</span> <span class="kc">true</span> <span class="p">{</span>
<a id="__codelineno-44-13" name="__codelineno-44-13" href="#__codelineno-44-13"></a> <span class="c1">// 获取节点 i 的父节点</span>
<a id="__codelineno-44-14" name="__codelineno-44-14" href="#__codelineno-44-14"></a> <span class="kd">let</span> <span class="nv">p</span> <span class="p">=</span> <span class="n">parent</span><span class="p">(</span><span class="n">i</span><span class="p">:</span> <span class="n">i</span><span class="p">)</span>
<a id="__codelineno-44-15" name="__codelineno-44-15" href="#__codelineno-44-15"></a> <span class="c1">// 当“越过根节点”或“节点无需修复”时，结束堆化</span>
<a id="__codelineno-44-15" name="__codelineno-44-15" href="#__codelineno-44-15"></a> <span class="c1">// 当“越过根节点”或“节点无须修复”时，结束堆化</span>
<a id="__codelineno-44-16" name="__codelineno-44-16" href="#__codelineno-44-16"></a> <span class="k">if</span> <span class="n">p</span> <span class="o">&lt;</span> <span class="mi">0</span> <span class="o">||</span> <span class="n">maxHeap</span><span class="p">[</span><span class="n">i</span><span class="p">]</span> <span class="o">&lt;=</span> <span class="n">maxHeap</span><span class="p">[</span><span class="n">p</span><span class="p">]</span> <span class="p">{</span>
<a id="__codelineno-44-17" name="__codelineno-44-17" href="#__codelineno-44-17"></a> <span class="k">break</span>
<a id="__codelineno-44-18" name="__codelineno-44-18" href="#__codelineno-44-18"></a> <span class="p">}</span>
@@ -4402,7 +4402,7 @@
<a id="__codelineno-45-12" name="__codelineno-45-12" href="#__codelineno-45-12"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="kc">true</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-45-13" name="__codelineno-45-13" href="#__codelineno-45-13"></a><span class="w"> </span><span class="c1">// 获取节点 i 的父节点</span>
<a id="__codelineno-45-14" name="__codelineno-45-14" href="#__codelineno-45-14"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">p</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">parent</span><span class="p">(</span><span class="n">i</span><span class="p">);</span>
<a id="__codelineno-45-15" name="__codelineno-45-15" href="#__codelineno-45-15"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无需修复”时，结束堆化</span>
<a id="__codelineno-45-15" name="__codelineno-45-15" href="#__codelineno-45-15"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无须修复”时，结束堆化</span>
<a id="__codelineno-45-16" name="__codelineno-45-16" href="#__codelineno-45-16"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">p</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="k">or</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">max_heap</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">items</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">&lt;=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">max_heap</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">items</span><span class="p">[</span><span class="n">p</span><span class="p">])</span><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-45-17" name="__codelineno-45-17" href="#__codelineno-45-17"></a><span class="w"> </span><span class="c1">// 交换两节点</span>
<a id="__codelineno-45-18" name="__codelineno-45-18" href="#__codelineno-45-18"></a><span class="w"> </span><span class="k">try</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">swap</span><span class="p">(</span><span class="n">i</span><span class="p">,</span><span class="w"> </span><span class="n">p</span><span class="p">);</span>
@@ -4426,7 +4426,7 @@
<a id="__codelineno-46-11" name="__codelineno-46-11" href="#__codelineno-46-11"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="kc">true</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-46-12" name="__codelineno-46-12" href="#__codelineno-46-12"></a><span class="w"> </span><span class="c1">// 获取节点 i 的父节点</span>
<a id="__codelineno-46-13" name="__codelineno-46-13" href="#__codelineno-46-13"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">p</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">_parent</span><span class="p">(</span><span class="n">i</span><span class="p">);</span>
<a id="__codelineno-46-14" name="__codelineno-46-14" href="#__codelineno-46-14"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无需修复”时，结束堆化</span>
<a id="__codelineno-46-14" name="__codelineno-46-14" href="#__codelineno-46-14"></a><span class="w"> </span><span class="c1">// 当“越过根节点”或“节点无须修复”时，结束堆化</span>
<a id="__codelineno-46-15" name="__codelineno-46-15" href="#__codelineno-46-15"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">p</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="m">0</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="n">_maxHeap</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">&lt;=</span><span class="w"> </span><span class="n">_maxHeap</span><span class="p">[</span><span class="n">p</span><span class="p">])</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-46-16" name="__codelineno-46-16" href="#__codelineno-46-16"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-46-17" name="__codelineno-46-17" href="#__codelineno-46-17"></a><span class="w"> </span><span class="p">}</span>
@@ -4456,7 +4456,7 @@
<a id="__codelineno-47-15" name="__codelineno-47-15" href="#__codelineno-47-15"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-47-16" name="__codelineno-47-16" href="#__codelineno-47-16"></a><span class="w"> </span><span class="c1">// 获取节点 i 的父节点</span>
<a id="__codelineno-47-17" name="__codelineno-47-17" href="#__codelineno-47-17"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="n">p</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="bp">Self</span>::<span class="n">parent</span><span class="p">(</span><span class="n">i</span><span class="p">);</span>
<a id="__codelineno-47-18" name="__codelineno-47-18" href="#__codelineno-47-18"></a><span class="w"> </span><span class="c1">// 当“节点无需修复”时，结束堆化</span>
<a id="__codelineno-47-18" name="__codelineno-47-18" href="#__codelineno-47-18"></a><span class="w"> </span><span class="c1">// 当“节点无须修复”时，结束堆化</span>
<a id="__codelineno-47-19" name="__codelineno-47-19" href="#__codelineno-47-19"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">max_heap</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">&lt;=</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">max_heap</span><span class="p">[</span><span class="n">p</span><span class="p">]</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-47-20" name="__codelineno-47-20" href="#__codelineno-47-20"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-47-21" name="__codelineno-47-21" href="#__codelineno-47-21"></a><span class="w"> </span><span class="p">}</span>
@@ -4477,7 +4477,7 @@
<li>交换完成后，将堆底从列表中删除（注意，由于已经交换，实际上删除的是原来的堆顶元素）。</li>
<li>从根节点开始，<strong>从顶至底执行堆化</strong>。</li>
</ol>
<p>顾名思义，<strong>从顶至底堆化的操作方向与从底至顶堆化相反</strong>，我们将根节点的值与其两个子节点的值进行比较，将最大的子节点与根节点交换；然后循环执行此操作，直到越过叶节点或遇到无需交换的节点时结束。</p>
<p>顾名思义，<strong>从顶至底堆化的操作方向与从底至顶堆化相反</strong>，我们将根节点的值与其两个子节点的值进行比较，将最大的子节点与根节点交换；然后循环执行此操作，直到越过叶节点或遇到无须交换的节点时结束。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="6:10"><input checked="checked" id="__tabbed_6_1" name="__tabbed_6" type="radio" /><input id="__tabbed_6_2" name="__tabbed_6" type="radio" /><input id="__tabbed_6_3" name="__tabbed_6" type="radio" /><input id="__tabbed_6_4" name="__tabbed_6" type="radio" /><input id="__tabbed_6_5" name="__tabbed_6" type="radio" /><input id="__tabbed_6_6" name="__tabbed_6" type="radio" /><input id="__tabbed_6_7" name="__tabbed_6" type="radio" /><input id="__tabbed_6_8" name="__tabbed_6" type="radio" /><input id="__tabbed_6_9" name="__tabbed_6" type="radio" /><input id="__tabbed_6_10" name="__tabbed_6" type="radio" /><div class="tabbed-labels"><label for="__tabbed_6_1">&lt;1&gt;</label><label for="__tabbed_6_2">&lt;2&gt;</label><label for="__tabbed_6_3">&lt;3&gt;</label><label for="__tabbed_6_4">&lt;4&gt;</label><label for="__tabbed_6_5">&lt;5&gt;</label><label for="__tabbed_6_6">&lt;6&gt;</label><label for="__tabbed_6_7">&lt;7&gt;</label><label for="__tabbed_6_8">&lt;8&gt;</label><label for="__tabbed_6_9">&lt;9&gt;</label><label for="__tabbed_6_10">&lt;10&gt;</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -4542,7 +4542,7 @@
<a id="__codelineno-48-22" name="__codelineno-48-22" href="#__codelineno-48-22"></a><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">l</span><span class="p">;</span>
<a id="__codelineno-48-23" name="__codelineno-48-23" href="#__codelineno-48-23"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">maxHeap</span><span class="p">.</span><span class="na">get</span><span class="p">(</span><span class="n">r</span><span class="p">)</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">maxHeap</span><span class="p">.</span><span class="na">get</span><span class="p">(</span><span class="n">ma</span><span class="p">))</span>
<a id="__codelineno-48-24" name="__codelineno-48-24" href="#__codelineno-48-24"></a><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">r</span><span class="p">;</span>
<a id="__codelineno-48-25" name="__codelineno-48-25" href="#__codelineno-48-25"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-48-25" name="__codelineno-48-25" href="#__codelineno-48-25"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-48-26" name="__codelineno-48-26" href="#__codelineno-48-26"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">ma</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">i</span><span class="p">)</span>
<a id="__codelineno-48-27" name="__codelineno-48-27" href="#__codelineno-48-27"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-48-28" name="__codelineno-48-28" href="#__codelineno-48-28"></a><span class="w"> </span><span class="c1">// 交换两节点</span>
@@ -4573,12 +4573,12 @@
<a id="__codelineno-49-17" name="__codelineno-49-17" href="#__codelineno-49-17"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="nb">true</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-49-18" name="__codelineno-49-18" href="#__codelineno-49-18"></a><span class="w"> </span><span class="c1">// 判断节点 i, l, r 中值最大的节点，记为 ma</span>
<a id="__codelineno-49-19" name="__codelineno-49-19" href="#__codelineno-49-19"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">l</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">left</span><span class="p">(</span><span class="n">i</span><span class="p">),</span><span class="w"> </span><span class="n">r</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">right</span><span class="p">(</span><span class="n">i</span><span class="p">),</span><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">i</span><span class="p">;</span>
<a id="__codelineno-49-20" name="__codelineno-49-20" href="#__codelineno-49-20"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-49-20" name="__codelineno-49-20" href="#__codelineno-49-20"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-49-21" name="__codelineno-49-21" href="#__codelineno-49-21"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">l</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">maxHeap</span><span class="p">[</span><span class="n">l</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">maxHeap</span><span class="p">[</span><span class="n">ma</span><span class="p">])</span>
<a id="__codelineno-49-22" name="__codelineno-49-22" href="#__codelineno-49-22"></a><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">l</span><span class="p">;</span>
<a id="__codelineno-49-23" name="__codelineno-49-23" href="#__codelineno-49-23"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">maxHeap</span><span class="p">[</span><span class="n">r</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">maxHeap</span><span class="p">[</span><span class="n">ma</span><span class="p">])</span>
<a id="__codelineno-49-24" name="__codelineno-49-24" href="#__codelineno-49-24"></a><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">r</span><span class="p">;</span>
<a id="__codelineno-49-25" name="__codelineno-49-25" href="#__codelineno-49-25"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-49-25" name="__codelineno-49-25" href="#__codelineno-49-25"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-49-26" name="__codelineno-49-26" href="#__codelineno-49-26"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">ma</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">i</span><span class="p">)</span>
<a id="__codelineno-49-27" name="__codelineno-49-27" href="#__codelineno-49-27"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-49-28" name="__codelineno-49-28" href="#__codelineno-49-28"></a><span class="w"> </span><span class="n">swap</span><span class="p">(</span><span class="n">maxHeap</span><span class="p">[</span><span class="n">i</span><span class="p">],</span><span class="w"> </span><span class="n">maxHeap</span><span class="p">[</span><span class="n">ma</span><span class="p">]);</span>
@@ -4612,7 +4612,7 @@
<a id="__codelineno-50-21" name="__codelineno-50-21" href="#__codelineno-50-21"></a> <span class="n">ma</span> <span class="o">=</span> <span class="n">l</span>
<a id="__codelineno-50-22" name="__codelineno-50-22" href="#__codelineno-50-22"></a> <span class="k">if</span> <span class="n">r</span> <span class="o">&lt;</span> <span class="bp">self</span><span class="o">.</span><span class="n">size</span><span class="p">()</span> <span class="ow">and</span> <span class="bp">self</span><span class="o">.</span><span class="n">max_heap</span><span class="p">[</span><span class="n">r</span><span class="p">]</span> <span class="o">&gt;</span> <span class="bp">self</span><span class="o">.</span><span class="n">max_heap</span><span class="p">[</span><span class="n">ma</span><span class="p">]:</span>
<a id="__codelineno-50-23" name="__codelineno-50-23" href="#__codelineno-50-23"></a> <span class="n">ma</span> <span class="o">=</span> <span class="n">r</span>
<a id="__codelineno-50-24" name="__codelineno-50-24" href="#__codelineno-50-24"></a> <span class="c1"># 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-50-24" name="__codelineno-50-24" href="#__codelineno-50-24"></a> <span class="c1"># 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-50-25" name="__codelineno-50-25" href="#__codelineno-50-25"></a> <span class="k">if</span> <span class="n">ma</span> <span class="o">==</span> <span class="n">i</span><span class="p">:</span>
<a id="__codelineno-50-26" name="__codelineno-50-26" href="#__codelineno-50-26"></a> <span class="k">break</span>
<a id="__codelineno-50-27" name="__codelineno-50-27" href="#__codelineno-50-27"></a> <span class="c1"># 交换两节点</span>
@@ -4652,7 +4652,7 @@
<a id="__codelineno-51-28" name="__codelineno-51-28" href="#__codelineno-51-28"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">r</span><span class="w"> </span><span class="p">&lt;</span><span class="w"> </span><span class="nx">h</span><span class="p">.</span><span class="nx">size</span><span class="p">()</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="nx">h</span><span class="p">.</span><span class="nx">data</span><span class="p">[</span><span class="nx">r</span><span class="p">].(</span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="p">&gt;</span><span class="w"> </span><span class="nx">h</span><span class="p">.</span><span class="nx">data</span><span class="p">[</span><span class="nx">max</span><span class="p">].(</span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-51-29" name="__codelineno-51-29" href="#__codelineno-51-29"></a><span class="w"> </span><span class="nx">max</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">r</span>
<a id="__codelineno-51-30" name="__codelineno-51-30" href="#__codelineno-51-30"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-51-31" name="__codelineno-51-31" href="#__codelineno-51-31"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-51-31" name="__codelineno-51-31" href="#__codelineno-51-31"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-51-32" name="__codelineno-51-32" href="#__codelineno-51-32"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">max</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-51-33" name="__codelineno-51-33" href="#__codelineno-51-33"></a><span class="w"> </span><span class="k">break</span>
<a id="__codelineno-51-34" name="__codelineno-51-34" href="#__codelineno-51-34"></a><span class="w"> </span><span class="p">}</span>
@@ -4688,7 +4688,7 @@
<a id="__codelineno-52-21" name="__codelineno-52-21" href="#__codelineno-52-21"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">i</span><span class="p">;</span>
<a id="__codelineno-52-22" name="__codelineno-52-22" href="#__codelineno-52-22"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">l</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">size</span><span class="p">()</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">maxHeap</span><span class="p">[</span><span class="nx">l</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">maxHeap</span><span class="p">[</span><span class="nx">ma</span><span class="p">])</span><span class="w"> </span><span class="nx">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">l</span><span class="p">;</span>
<a id="__codelineno-52-23" name="__codelineno-52-23" href="#__codelineno-52-23"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">size</span><span class="p">()</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">maxHeap</span><span class="p">[</span><span class="nx">r</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">maxHeap</span><span class="p">[</span><span class="nx">ma</span><span class="p">])</span><span class="w"> </span><span class="nx">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">r</span><span class="p">;</span>
<a id="__codelineno-52-24" name="__codelineno-52-24" href="#__codelineno-52-24"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-52-24" name="__codelineno-52-24" href="#__codelineno-52-24"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-52-25" name="__codelineno-52-25" href="#__codelineno-52-25"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">ma</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="nx">i</span><span class="p">)</span><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-52-26" name="__codelineno-52-26" href="#__codelineno-52-26"></a><span class="w"> </span><span class="c1">// 交换两节点</span>
<a id="__codelineno-52-27" name="__codelineno-52-27" href="#__codelineno-52-27"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">swap</span><span class="p">(</span><span class="nx">i</span><span class="p">,</span><span class="w"> </span><span class="nx">ma</span><span class="p">);</span>
@@ -4722,7 +4722,7 @@
<a id="__codelineno-53-21" name="__codelineno-53-21" href="#__codelineno-53-21"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">i</span><span class="p">;</span>
<a id="__codelineno-53-22" name="__codelineno-53-22" href="#__codelineno-53-22"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">l</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">size</span><span class="p">()</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">maxHeap</span><span class="p">[</span><span class="nx">l</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">maxHeap</span><span class="p">[</span><span class="nx">ma</span><span class="p">])</span><span class="w"> </span><span class="nx">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">l</span><span class="p">;</span>
<a id="__codelineno-53-23" name="__codelineno-53-23" href="#__codelineno-53-23"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">size</span><span class="p">()</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">maxHeap</span><span class="p">[</span><span class="nx">r</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">maxHeap</span><span class="p">[</span><span class="nx">ma</span><span class="p">])</span><span class="w"> </span><span class="nx">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">r</span><span class="p">;</span>
<a id="__codelineno-53-24" name="__codelineno-53-24" href="#__codelineno-53-24"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-53-24" name="__codelineno-53-24" href="#__codelineno-53-24"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-53-25" name="__codelineno-53-25" href="#__codelineno-53-25"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">ma</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="nx">i</span><span class="p">)</span><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-53-26" name="__codelineno-53-26" href="#__codelineno-53-26"></a><span class="w"> </span><span class="c1">// 交换两节点</span>
<a id="__codelineno-53-27" name="__codelineno-53-27" href="#__codelineno-53-27"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">swap</span><span class="p">(</span><span class="nx">i</span><span class="p">,</span><span class="w"> </span><span class="nx">ma</span><span class="p">);</span>
@@ -4765,7 +4765,7 @@
<a id="__codelineno-54-30" name="__codelineno-54-30" href="#__codelineno-54-30"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">size</span><span class="p">(</span><span class="n">h</span><span class="p">)</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">h</span><span class="o">-&gt;</span><span class="n">data</span><span class="p">[</span><span class="n">r</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">h</span><span class="o">-&gt;</span><span class="n">data</span><span class="p">[</span><span class="n">max</span><span class="p">])</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-54-31" name="__codelineno-54-31" href="#__codelineno-54-31"></a><span class="w"> </span><span class="n">max</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">r</span><span class="p">;</span>
<a id="__codelineno-54-32" name="__codelineno-54-32" href="#__codelineno-54-32"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-54-33" name="__codelineno-54-33" href="#__codelineno-54-33"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-54-33" name="__codelineno-54-33" href="#__codelineno-54-33"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-54-34" name="__codelineno-54-34" href="#__codelineno-54-34"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">max</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-54-35" name="__codelineno-54-35" href="#__codelineno-54-35"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-54-36" name="__codelineno-54-36" href="#__codelineno-54-36"></a><span class="w"> </span><span class="p">}</span>
@@ -4844,7 +4844,7 @@
<a id="__codelineno-56-28" name="__codelineno-56-28" href="#__codelineno-56-28"></a> <span class="k">if</span> <span class="n">r</span> <span class="o">&lt;</span> <span class="n">size</span><span class="p">(),</span> <span class="n">maxHeap</span><span class="p">[</span><span class="n">r</span><span class="p">]</span> <span class="o">&gt;</span> <span class="n">maxHeap</span><span class="p">[</span><span class="n">ma</span><span class="p">]</span> <span class="p">{</span>
<a id="__codelineno-56-29" name="__codelineno-56-29" href="#__codelineno-56-29"></a> <span class="n">ma</span> <span class="p">=</span> <span class="n">r</span>
<a id="__codelineno-56-30" name="__codelineno-56-30" href="#__codelineno-56-30"></a> <span class="p">}</span>
<a id="__codelineno-56-31" name="__codelineno-56-31" href="#__codelineno-56-31"></a> <span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-56-31" name="__codelineno-56-31" href="#__codelineno-56-31"></a> <span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-56-32" name="__codelineno-56-32" href="#__codelineno-56-32"></a> <span class="k">if</span> <span class="n">ma</span> <span class="p">==</span> <span class="n">i</span> <span class="p">{</span>
<a id="__codelineno-56-33" name="__codelineno-56-33" href="#__codelineno-56-33"></a> <span class="k">break</span>
<a id="__codelineno-56-34" name="__codelineno-56-34" href="#__codelineno-56-34"></a> <span class="p">}</span>
@@ -4881,7 +4881,7 @@
<a id="__codelineno-57-22" name="__codelineno-57-22" href="#__codelineno-57-22"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">i</span><span class="p">;</span>
<a id="__codelineno-57-23" name="__codelineno-57-23" href="#__codelineno-57-23"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">l</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="k">and</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">max_heap</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">items</span><span class="p">[</span><span class="n">l</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">max_heap</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">items</span><span class="p">[</span><span class="n">ma</span><span class="p">])</span><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">l</span><span class="p">;</span>
<a id="__codelineno-57-24" name="__codelineno-57-24" href="#__codelineno-57-24"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="k">and</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">max_heap</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">items</span><span class="p">[</span><span class="n">r</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">max_heap</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">items</span><span class="p">[</span><span class="n">ma</span><span class="p">])</span><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">r</span><span class="p">;</span>
<a id="__codelineno-57-25" name="__codelineno-57-25" href="#__codelineno-57-25"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-57-25" name="__codelineno-57-25" href="#__codelineno-57-25"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-57-26" name="__codelineno-57-26" href="#__codelineno-57-26"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">ma</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-57-27" name="__codelineno-57-27" href="#__codelineno-57-27"></a><span class="w"> </span><span class="c1">// 交换两节点</span>
<a id="__codelineno-57-28" name="__codelineno-57-28" href="#__codelineno-57-28"></a><span class="w"> </span><span class="k">try</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">swap</span><span class="p">(</span><span class="n">i</span><span class="p">,</span><span class="w"> </span><span class="n">ma</span><span class="p">);</span>
@@ -4915,7 +4915,7 @@
<a id="__codelineno-58-21" name="__codelineno-58-21" href="#__codelineno-58-21"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">i</span><span class="p">;</span>
<a id="__codelineno-58-22" name="__codelineno-58-22" href="#__codelineno-58-22"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">l</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">_maxHeap</span><span class="p">[</span><span class="n">l</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">_maxHeap</span><span class="p">[</span><span class="n">ma</span><span class="p">])</span><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">l</span><span class="p">;</span>
<a id="__codelineno-58-23" name="__codelineno-58-23" href="#__codelineno-58-23"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">_maxHeap</span><span class="p">[</span><span class="n">r</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">_maxHeap</span><span class="p">[</span><span class="n">ma</span><span class="p">])</span><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">r</span><span class="p">;</span>
<a id="__codelineno-58-24" name="__codelineno-58-24" href="#__codelineno-58-24"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-58-24" name="__codelineno-58-24" href="#__codelineno-58-24"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-58-25" name="__codelineno-58-25" href="#__codelineno-58-25"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">ma</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-58-26" name="__codelineno-58-26" href="#__codelineno-58-26"></a><span class="w"> </span><span class="c1">// 交换两节点</span>
<a id="__codelineno-58-27" name="__codelineno-58-27" href="#__codelineno-58-27"></a><span class="w"> </span><span class="n">_swap</span><span class="p">(</span><span class="n">i</span><span class="p">,</span><span class="w"> </span><span class="n">ma</span><span class="p">);</span>
@@ -4953,7 +4953,7 @@
<a id="__codelineno-59-25" name="__codelineno-59-25" href="#__codelineno-59-25"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="n">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">max_heap</span><span class="p">[</span><span class="n">r</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">max_heap</span><span class="p">[</span><span class="n">ma</span><span class="p">]</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-59-26" name="__codelineno-59-26" href="#__codelineno-59-26"></a><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">r</span><span class="p">;</span>
<a id="__codelineno-59-27" name="__codelineno-59-27" href="#__codelineno-59-27"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-59-28" name="__codelineno-59-28" href="#__codelineno-59-28"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-59-28" name="__codelineno-59-28" href="#__codelineno-59-28"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-59-29" name="__codelineno-59-29" href="#__codelineno-59-29"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-59-30" name="__codelineno-59-30" href="#__codelineno-59-30"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-59-31" name="__codelineno-59-31" href="#__codelineno-59-31"></a><span class="w"> </span><span class="p">}</span>
chapter_introduction/algorithms_are_everywhere/index.html
+9 -9
View File
@@ -3348,11 +3348,11 @@
<h1 id="11">1.1 &nbsp; 算法无处不在<a class="headerlink" href="#11" title="Permanent link">&para;</a></h1>
<p>当我们听到“算法”这个词时，很自然地会想到数学。然而实际上，许多算法并不涉及复杂数学，而是更多地依赖于基本逻辑，这些逻辑在我们的日常生活中处处可见。</p>
<p>在正式探讨算法之前，有一个有趣的事实值得分享：<strong>你已经在不知不觉中学会了许多算法，并习惯将它们应用到日常生活中了</strong>。下面，我将举几个具体例子来证实这一点。</p>
<p><strong>例一：查阅字典</strong>。在字典里，每个汉字都对应一个拼音，而字典是按照拼音的英文字母顺序排列的。假设我们需要查找一个拼音首字母为 <span class="arithmatex">\(r\)</span> 的字，通常会这样操作：</p>
<p><strong>例一：查阅字典</strong>。在字典里，每个汉字都对应一个拼音，而字典是按照拼音字母顺序排列的。假设我们需要查找一个拼音首字母为 <span class="arithmatex">\(r\)</span> 的字，通常会按照下图所示的方式实现。</p>
<ol>
<li>翻开字典约一半的页数，查看该页首字母是什么，假设首字母为 <span class="arithmatex">\(m\)</span> 。</li>
<li>由于在英文字母表中 <span class="arithmatex">\(r\)</span> 位于 <span class="arithmatex">\(m\)</span> 之后，所以排除字典前半部分，查找范围缩小到后半部分。</li>
<li>不断重复步骤 1-2 ，直至找到拼音首字母为 <span class="arithmatex">\(r\)</span> 的页码为止。</li>
<li>翻开字典约一半的页数，查看该页的首字母是什么，假设首字母为 <span class="arithmatex">\(m\)</span> 。</li>
<li>由于在拼音字母表中 <span class="arithmatex">\(r\)</span> 位于 <span class="arithmatex">\(m\)</span> 之后，所以排除字典前半部分，查找范围缩小到后半部分。</li>
<li>不断重复步骤 <code>1.</code> 和 步骤 <code>2.</code> ，直至找到拼音首字母为 <span class="arithmatex">\(r\)</span> 的页码为止。</li>
</ol>
<div class="tabbed-set tabbed-alternate" data-tabs="1:5"><input checked="checked" id="__tabbed_1_1" name="__tabbed_1" type="radio" /><input id="__tabbed_1_2" name="__tabbed_1" type="radio" /><input id="__tabbed_1_3" name="__tabbed_1" type="radio" /><input id="__tabbed_1_4" name="__tabbed_1" type="radio" /><input id="__tabbed_1_5" name="__tabbed_1" type="radio" /><div class="tabbed-labels"><label for="__tabbed_1_1">&lt;1&gt;</label><label for="__tabbed_1_2">&lt;2&gt;</label><label for="__tabbed_1_3">&lt;3&gt;</label><label for="__tabbed_1_4">&lt;4&gt;</label><label for="__tabbed_1_5">&lt;5&gt;</label></div>
<div class="tabbed-content">
@@ -3375,8 +3375,8 @@
</div>
<p align="center"> 图：查字典步骤 </p>
<p>查阅字典这个小学生必备技能，实际上就是著名的「二分查找」。从数据结构的角度，我们可以把字典视为一个已排序的「数组」；从算法的角度，我们可以将上述查字典的一系列操作看作是「二分查找」算法。</p>
<p><strong>例二：整理扑克</strong>。我们在打牌时，每局都需要整理扑克牌，使其从小到大排列，实现流程如下：</p>
<p>查阅字典这个小学生必备技能，实际上就是著名的二分查找算法。从数据结构的角度，我们可以把字典视为一个已排序的「数组」；从算法的角度，我们可以将上述查字典的一系列操作看作是「二分查找」。</p>
<p><strong>例二：整理扑克</strong>。我们在打牌时，每局都需要整理扑克牌，使其从小到大排列，实现流程如下图所示。</p>
<ol>
<li>将扑克牌划分为“有序”和“无序”两部分，并假设初始状态下最左 1 张扑克牌已经有序。</li>
<li>在无序部分抽出一张扑克牌，插入至有序部分的正确位置；完成后最左 2 张扑克已经有序。</li>
@@ -3386,9 +3386,9 @@
<p align="center"> 图：扑克排序步骤 </p>
<p>上述整理扑克牌的方法本质上是「插入排序」算法，它在处理小型数据集时非常高效。许多编程语言的排序库函数中都存在插入排序的身影。</p>
<p><strong>例三：货币找零</strong>。假设我们在超市购买了 <span class="arithmatex">\(69\)</span> 元的商品，给收银员付了 <span class="arithmatex">\(100\)</span> 元，则收银员需要给我们找 <span class="arithmatex">\(31\)</span> 元。他会很自然地完成以下思考：</p>
<p><strong>例三：货币找零</strong>。假设我们在超市购买了 <span class="arithmatex">\(69\)</span> 元的商品，给收银员付了 <span class="arithmatex">\(100\)</span> 元，则收银员需要找我们 <span class="arithmatex">\(31\)</span> 元。他会很自然地完成如下图所示的思考。</p>
<ol>
<li>可选项是比 <span class="arithmatex">\(31\)</span> 元面值更小的货币，包括 <span class="arithmatex">\(1\)</span> , <span class="arithmatex">\(5\)</span> , <span class="arithmatex">\(10\)</span> , <span class="arithmatex">\(20\)</span> 元。</li>
<li>可选项是比 <span class="arithmatex">\(31\)</span> 元面值更小的货币，包括 <span class="arithmatex">\(1\)</span> 元、<span class="arithmatex">\(5\)</span> 元、<span class="arithmatex">\(10\)</span> 元、<span class="arithmatex">\(20\)</span> 元。</li>
<li>从可选项中拿出最大的 <span class="arithmatex">\(20\)</span> 元，剩余 <span class="arithmatex">\(31 - 20 = 11\)</span> 元。</li>
<li>从剩余可选项中拿出最大的 <span class="arithmatex">\(10\)</span> 元，剩余 <span class="arithmatex">\(11 - 10 = 1\)</span> 元。</li>
<li>从剩余可选项中拿出最大的 <span class="arithmatex">\(1\)</span> 元，剩余 <span class="arithmatex">\(1 - 1 = 0\)</span> 元。</li>
@@ -3401,7 +3401,7 @@
<p>小到烹饪一道菜，大到星际航行，几乎所有问题的解决都离不开算法。计算机的出现使我们能够通过编程将数据结构存储在内存中，同时编写代码调用 CPU 和 GPU 执行算法。这样一来，我们就能把生活中的问题转移到计算机上，以更高效的方式解决各种复杂问题。</p>
<div class="admonition tip">
<p class="admonition-title">Tip</p>
<p>阅读至此，如果你对数据结构、算法、数组和二分查找等概念仍感到一知半解，那么太好了！因为这正是本书存在的意义。接下来，这本书将引导你一步步深入数据结构与算法的知识殿堂。</p>
<p>阅读至此，如果你对数据结构、算法、数组和二分查找等概念仍感到一知半解，请继续往下阅读，因为这正是本书存在的意义。接下来，这本书将引导你一步步深入数据结构与算法的知识殿堂。</p>
</div>
chapter_introduction/summary/index.html
+4 -4
View File
@@ -3348,12 +3348,12 @@
<h1 id="13">1.3 &nbsp; 小结<a class="headerlink" href="#13" title="Permanent link">&para;</a></h1>
<ul>
<li>算法在日常生活中无处不在，并不是遥不可及的高深知识。实际上，我们已经在不知不觉中学会了许多算法，用以解决生活中的大小问题。</li>
<li>查阅字典的原理与二分查找算法相一致。二分查找体现了分而治之的重要算法思想。</li>
<li>整理扑克的过程与插入排序算法非常类似。插入排序适合排序小型数据集。</li>
<li>货币找零的步骤本质上是贪心算法，每一步都采取当前看来的最好选择。</li>
<li>查阅字典的原理与二分查找算法相一致。二分查找算法体现了分而治之的重要算法思想。</li>
<li>整理扑克的过程与插入排序算法非常类似。插入排序算法适合排序小型数据集。</li>
<li>货币找零的步骤本质上是贪心算法，每一步都采取当前看来的最好的选择。</li>
<li>算法是在有限时间内解决特定问题的一组指令或操作步骤，而数据结构是计算机中组织和存储数据的方式。</li>
<li>数据结构与算法紧密相连。数据结构是算法的基石，而算法则是发挥数据结构作用的舞台。</li>
<li>乐高积木对应于数据，积木形状和连接方式代表数据结构，拼装积木的步骤则对应算法。</li>
<li>我们可以将数据结构与算法类比为拼装积木，积木代表数据，积木的形状和连接方式代表数据结构，拼装积木的步骤则对应算法。</li>
</ul>
chapter_introduction/what_is_dsa/index.html
+7 -7
View File
@@ -3427,14 +3427,14 @@
<h1 id="12">1.2 &nbsp; 算法是什么<a class="headerlink" href="#12" title="Permanent link">&para;</a></h1>
<h2 id="121">1.2.1 &nbsp; 算法定义<a class="headerlink" href="#121" title="Permanent link">&para;</a></h2>
<p>「算法 Algorithm」是在有限时间内解决特定问题的一组指令或操作步骤。它具有以下特性：</p>
<p>「算法 algorithm」是在有限时间内解决特定问题的一组指令或操作步骤，它具有以下特性：</p>
<ul>
<li>问题是明确的，包含清晰的输入和输出定义。</li>
<li>具有可行性，能够在有限步骤、时间和内存空间下完成。</li>
<li>各步骤都有确定的含义，相同的输入和运行条件下，输出始终相同。</li>
</ul>
<h2 id="122">1.2.2 &nbsp; 数据结构定义<a class="headerlink" href="#122" title="Permanent link">&para;</a></h2>
<p>「数据结构 Data Structure」是计算机中组织和存储数据的方式。它的设计目标包括：</p>
<p>「数据结构 data structure」是计算机中组织和存储数据的方式，它的设计目标如下：</p>
<ul>
<li>空间占用尽量减少，节省计算机内存。</li>
<li>数据操作尽可能快速，涵盖数据访问、添加、删除、更新等。</li>
@@ -3446,16 +3446,16 @@
<li>图相较于链表，提供了更丰富的逻辑信息，但需要占用更大的内存空间。</li>
</ul>
<h2 id="123">1.2.3 &nbsp; 数据结构与算法的关系<a class="headerlink" href="#123" title="Permanent link">&para;</a></h2>
<p>数据结构与算法高度相关、紧密结合，具体表现在：</p>
<p>数据结构与算法高度相关、紧密结合，具体表现在以下几个方面。</p>
<ul>
<li>数据结构是算法的基石。数据结构为算法提供了结构化存储的数据，以及用于操作数据的方法。</li>
<li>算法是数据结构发挥的舞台。数据结构本身仅存储数据信息，通过结合算法才能解决特定问题。</li>
<li>特定算法通常有对应最优的数据结构。算法通常可以基于不同的数据结构进行实现，但最终执行效率可能相差很大。</li>
<li>算法是数据结构发挥作用的舞台。数据结构本身仅存储数据信息，通过结合算法才能解决特定问题。</li>
<li>特定算法通常会有对应最优的数据结构。算法通常可以基于不同的数据结构进行实现，但最终执行效率可能相差很大。</li>
</ul>
<p><img alt="数据结构与算法的关系" src="../what_is_dsa.assets/relationship_between_data_structure_and_algorithm.png" /></p>
<p align="center"> 图：数据结构与算法的关系 </p>
<p>数据结构与算法犹如拼装积木。一套积木，除了包含许多零件之外，还附有详细的组装说明书。我们按照说明书一步步操作，就能组装出精美的积木模型。</p>
<p>数据结构与算法犹如上图所示的拼装积木。一套积木，除了包含许多零件之外，还附有详细的组装说明书。我们按照说明书一步步操作，就能组装出精美的积木模型。</p>
<p><img alt="拼装积木" src="../what_is_dsa.assets/assembling_blocks.jpg" /></p>
<p align="center"> 图：拼装积木 </p>
@@ -3467,7 +3467,7 @@
<thead>
<tr>
<th>数据结构与算法</th>
<th>积木</th>
<th>拼装积木</th>
</tr>
</thead>
<tbody>
chapter_searching/binary_search/index.html
+2 -2
View File
@@ -3509,7 +3509,7 @@
<a id="__codelineno-2-4" name="__codelineno-2-4" href="#__codelineno-2-4"></a> <span class="n">i</span><span class="p">,</span> <span class="n">j</span> <span class="o">=</span> <span class="mi">0</span><span class="p">,</span> <span class="nb">len</span><span class="p">(</span><span class="n">nums</span><span class="p">)</span> <span class="o">-</span> <span class="mi">1</span>
<a id="__codelineno-2-5" name="__codelineno-2-5" href="#__codelineno-2-5"></a> <span class="c1"># 循环，当搜索区间为空时跳出（当 i &gt; j 时为空）</span>
<a id="__codelineno-2-6" name="__codelineno-2-6" href="#__codelineno-2-6"></a> <span class="k">while</span> <span class="n">i</span> <span class="o">&lt;=</span> <span class="n">j</span><span class="p">:</span>
<a id="__codelineno-2-7" name="__codelineno-2-7" href="#__codelineno-2-7"></a> <span class="c1"># 理论上 Python 的数字可以无限大（取决于内存大小），无需考虑大数越界问题</span>
<a id="__codelineno-2-7" name="__codelineno-2-7" href="#__codelineno-2-7"></a> <span class="c1"># 理论上 Python 的数字可以无限大（取决于内存大小），无须考虑大数越界问题</span>
<a id="__codelineno-2-8" name="__codelineno-2-8" href="#__codelineno-2-8"></a> <span class="n">m</span> <span class="o">=</span> <span class="p">(</span><span class="n">i</span> <span class="o">+</span> <span class="n">j</span><span class="p">)</span> <span class="o">//</span> <span class="mi">2</span> <span class="c1"># 计算中点索引 m</span>
<a id="__codelineno-2-9" name="__codelineno-2-9" href="#__codelineno-2-9"></a> <span class="k">if</span> <span class="n">nums</span><span class="p">[</span><span class="n">m</span><span class="p">]</span> <span class="o">&lt;</span> <span class="n">target</span><span class="p">:</span>
<a id="__codelineno-2-10" name="__codelineno-2-10" href="#__codelineno-2-10"></a> <span class="n">i</span> <span class="o">=</span> <span class="n">m</span> <span class="o">+</span> <span class="mi">1</span> <span class="c1"># 此情况说明 target 在区间 [m+1, j] 中</span>
@@ -3996,7 +3996,7 @@
<p>二分查找在时间和空间方面都有较好的性能：</p>
<ul>
<li>二分查找的时间效率高。在大数据量下，对数阶的时间复杂度具有显著优势。例如，当数据大小 <span class="arithmatex">\(n = 2^{20}\)</span> 时，线性查找需要 <span class="arithmatex">\(2^{20} = 1048576\)</span> 轮循环，而二分查找仅需 <span class="arithmatex">\(\log_2 2^{20} = 20\)</span> 轮循环。</li>
<li>二分查找无需额外空间。相较于需要借助额外空间的搜索算法（例如哈希查找），二分查找更加节省空间。</li>
<li>二分查找无须额外空间。相较于需要借助额外空间的搜索算法（例如哈希查找），二分查找更加节省空间。</li>
</ul>
<p>然而，二分查找并非适用于所有情况，原因如下：</p>
<ul>
chapter_searching/binary_search_edge/index.html
+1 -1
View File
@@ -3726,7 +3726,7 @@
<p>代码在此省略，值得注意的有：</p>
<ul>
<li>给定数组不包含小数，这意味着我们无需关心如何处理相等的情况。</li>
<li>给定数组不包含小数，这意味着我们无须关心如何处理相等的情况。</li>
<li>因为该方法引入了小数，所以需要将函数中的变量 <code>target</code> 改为浮点数类型。</li>
</ul>
chapter_searching/searching_algorithm_revisited/index.html
+2 -2
View File
@@ -3439,7 +3439,7 @@
<li>「线性搜索」适用于数组和链表等线性数据结构。它从数据结构的一端开始，逐个访问元素，直到找到目标元素或到达另一端仍没有找到目标元素为止。</li>
<li>「广度优先搜索」和「深度优先搜索」是图和树的两种遍历策略。广度优先搜索从初始节点开始逐层搜索，由近及远地访问各个节点。深度优先搜索是从初始节点开始，沿着一条路径走到头为止，再回溯并尝试其他路径，直到遍历完整个数据结构。</li>
</ul>
<p>暴力搜索的优点是简单且通用性好，<strong>无需对数据做预处理和借助额外的数据结构</strong>。</p>
<p>暴力搜索的优点是简单且通用性好，<strong>无须对数据做预处理和借助额外的数据结构</strong>。</p>
<p>然而，<strong>此类算法的时间复杂度为 <span class="arithmatex">\(O(n)\)</span></strong> ，其中 <span class="arithmatex">\(n\)</span> 为元素数量，因此在数据量较大的情况下性能较差。</p>
<h2 id="1052">10.5.2 &nbsp; 自适应搜索<a class="headerlink" href="#1052" title="Permanent link">&para;</a></h2>
<p>自适应搜索利用数据的特有属性（例如有序性）来优化搜索过程，从而更高效地定位目标元素。</p>
@@ -3522,7 +3522,7 @@
<p>除了以上表格内容，搜索算法的选择还取决于数据体量、搜索性能要求、数据查询与更新频率等。</p>
<p><strong>线性搜索</strong></p>
<ul>
<li>通用性较好，无需任何数据预处理操作。假如我们仅需查询一次数据，那么其他三种方法的数据预处理的时间比线性搜索的时间还要更长。</li>
<li>通用性较好，无须任何数据预处理操作。假如我们仅需查询一次数据，那么其他三种方法的数据预处理的时间比线性搜索的时间还要更长。</li>
<li>适用于体量较小的数据，此情况下时间复杂度对效率影响较小。</li>
<li>适用于数据更新频率较高的场景，因为该方法不需要对数据进行任何额外维护。</li>
</ul>
chapter_searching/summary/index.html
+2 -2
View File
@@ -3348,10 +3348,10 @@
<h1 id="106">10.6 &nbsp; 小结<a class="headerlink" href="#106" title="Permanent link">&para;</a></h1>
<ul>
<li>二分查找依赖于数据的有序性，通过循环逐步缩减一半搜索区间来实现查找。它要求输入数据有序，且仅适用于数组或基于数组实现的数据结构。</li>
<li>暴力搜索通过遍历数据结构来定位数据。线性搜索适用于数组和链表，广度优先搜索和深度优先搜索适用于图和树。此类算法通用性好，无需对数据预处理，但时间复杂度 <span class="arithmatex">\(O(n)\)</span> 较高。</li>
<li>暴力搜索通过遍历数据结构来定位数据。线性搜索适用于数组和链表，广度优先搜索和深度优先搜索适用于图和树。此类算法通用性好，无须对数据预处理，但时间复杂度 <span class="arithmatex">\(O(n)\)</span> 较高。</li>
<li>哈希查找、树查找和二分查找属于高效搜索方法，可在特定数据结构中快速定位目标元素。此类算法效率高，时间复杂度可达 <span class="arithmatex">\(O(\log n)\)</span> 甚至 <span class="arithmatex">\(O(1)\)</span> ，但通常需要借助额外数据结构。</li>
<li>实际中，我们需要对数据体量、搜索性能要求、数据查询和更新频率等因素进行具体分析，从而选择合适的搜索方法。</li>
<li>线性搜索适用于小型或频繁更新的数据；二分查找适用于大型、排序的数据；哈希查找适合对查询效率要求较高且无需范围查询的数据；树查找适用于需要维护顺序和支持范围查询的大型动态数据。</li>
<li>线性搜索适用于小型或频繁更新的数据；二分查找适用于大型、排序的数据；哈希查找适合对查询效率要求较高且无须范围查询的数据；树查找适用于需要维护顺序和支持范围查询的大型动态数据。</li>
<li>用哈希查找替换线性查找是一种常用的优化运行时间的策略，可将时间复杂度从 <span class="arithmatex">\(O(n)\)</span> 降低至 <span class="arithmatex">\(O(1)\)</span> 。 </li>
</ul>
chapter_sorting/bubble_sort/index.html
+1 -1
View File
@@ -3461,7 +3461,7 @@
<li>首先，对 <span class="arithmatex">\(n\)</span> 个元素执行“冒泡”，<strong>将数组的最大元素交换至正确位置</strong>，</li>
<li>接下来，对剩余 <span class="arithmatex">\(n - 1\)</span> 个元素执行“冒泡”，<strong>将第二大元素交换至正确位置</strong>。</li>
<li>以此类推，经过 <span class="arithmatex">\(n - 1\)</span> 轮“冒泡”后，<strong>前 <span class="arithmatex">\(n - 1\)</span> 大的元素都被交换至正确位置</strong>。</li>
<li>仅剩的一个元素必定是最小元素，无需排序，因此数组排序完成。</li>
<li>仅剩的一个元素必定是最小元素，无须排序，因此数组排序完成。</li>
</ol>
<p><img alt="冒泡排序流程" src="../bubble_sort.assets/bubble_sort_overview.png" /></p>
<p align="center"> 图：冒泡排序流程 </p>
chapter_sorting/heap_sort/index.html
+11 -11
View File
@@ -3488,7 +3488,7 @@
<a id="__codelineno-0-9" name="__codelineno-0-9" href="#__codelineno-0-9"></a><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">l</span><span class="p">;</span>
<a id="__codelineno-0-10" name="__codelineno-0-10" href="#__codelineno-0-10"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">n</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">nums</span><span class="o">[</span><span class="n">r</span><span class="o">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">nums</span><span class="o">[</span><span class="n">ma</span><span class="o">]</span><span class="p">)</span>
<a id="__codelineno-0-11" name="__codelineno-0-11" href="#__codelineno-0-11"></a><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">r</span><span class="p">;</span>
<a id="__codelineno-0-12" name="__codelineno-0-12" href="#__codelineno-0-12"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-0-12" name="__codelineno-0-12" href="#__codelineno-0-12"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-0-13" name="__codelineno-0-13" href="#__codelineno-0-13"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">ma</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">i</span><span class="p">)</span>
<a id="__codelineno-0-14" name="__codelineno-0-14" href="#__codelineno-0-14"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-0-15" name="__codelineno-0-15" href="#__codelineno-0-15"></a><span class="w"> </span><span class="c1">// 交换两节点</span>
@@ -3530,7 +3530,7 @@
<a id="__codelineno-1-9" name="__codelineno-1-9" href="#__codelineno-1-9"></a><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">l</span><span class="p">;</span>
<a id="__codelineno-1-10" name="__codelineno-1-10" href="#__codelineno-1-10"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">n</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">r</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">ma</span><span class="p">])</span>
<a id="__codelineno-1-11" name="__codelineno-1-11" href="#__codelineno-1-11"></a><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">r</span><span class="p">;</span>
<a id="__codelineno-1-12" name="__codelineno-1-12" href="#__codelineno-1-12"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-1-12" name="__codelineno-1-12" href="#__codelineno-1-12"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-1-13" name="__codelineno-1-13" href="#__codelineno-1-13"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">ma</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-1-14" name="__codelineno-1-14" href="#__codelineno-1-14"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-1-15" name="__codelineno-1-15" href="#__codelineno-1-15"></a><span class="w"> </span><span class="p">}</span>
@@ -3569,7 +3569,7 @@
<a id="__codelineno-2-9" name="__codelineno-2-9" href="#__codelineno-2-9"></a> <span class="n">ma</span> <span class="o">=</span> <span class="n">l</span>
<a id="__codelineno-2-10" name="__codelineno-2-10" href="#__codelineno-2-10"></a> <span class="k">if</span> <span class="n">r</span> <span class="o">&lt;</span> <span class="n">n</span> <span class="ow">and</span> <span class="n">nums</span><span class="p">[</span><span class="n">r</span><span class="p">]</span> <span class="o">&gt;</span> <span class="n">nums</span><span class="p">[</span><span class="n">ma</span><span class="p">]:</span>
<a id="__codelineno-2-11" name="__codelineno-2-11" href="#__codelineno-2-11"></a> <span class="n">ma</span> <span class="o">=</span> <span class="n">r</span>
<a id="__codelineno-2-12" name="__codelineno-2-12" href="#__codelineno-2-12"></a> <span class="c1"># 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-2-12" name="__codelineno-2-12" href="#__codelineno-2-12"></a> <span class="c1"># 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-2-13" name="__codelineno-2-13" href="#__codelineno-2-13"></a> <span class="k">if</span> <span class="n">ma</span> <span class="o">==</span> <span class="n">i</span><span class="p">:</span>
<a id="__codelineno-2-14" name="__codelineno-2-14" href="#__codelineno-2-14"></a> <span class="k">break</span>
<a id="__codelineno-2-15" name="__codelineno-2-15" href="#__codelineno-2-15"></a> <span class="c1"># 交换两节点</span>
@@ -3604,7 +3604,7 @@
<a id="__codelineno-3-11" name="__codelineno-3-11" href="#__codelineno-3-11"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">r</span><span class="w"> </span><span class="p">&lt;</span><span class="w"> </span><span class="nx">n</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="p">(</span><span class="o">*</span><span class="nx">nums</span><span class="p">)[</span><span class="nx">r</span><span class="p">]</span><span class="w"> </span><span class="p">&gt;</span><span class="w"> </span><span class="p">(</span><span class="o">*</span><span class="nx">nums</span><span class="p">)[</span><span class="nx">ma</span><span class="p">]</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-3-12" name="__codelineno-3-12" href="#__codelineno-3-12"></a><span class="w"> </span><span class="nx">ma</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">r</span>
<a id="__codelineno-3-13" name="__codelineno-3-13" href="#__codelineno-3-13"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-3-14" name="__codelineno-3-14" href="#__codelineno-3-14"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-3-14" name="__codelineno-3-14" href="#__codelineno-3-14"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-3-15" name="__codelineno-3-15" href="#__codelineno-3-15"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">ma</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-3-16" name="__codelineno-3-16" href="#__codelineno-3-16"></a><span class="w"> </span><span class="k">break</span>
<a id="__codelineno-3-17" name="__codelineno-3-17" href="#__codelineno-3-17"></a><span class="w"> </span><span class="p">}</span>
@@ -3645,7 +3645,7 @@
<a id="__codelineno-4-11" name="__codelineno-4-11" href="#__codelineno-4-11"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">n</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="nx">nums</span><span class="p">[</span><span class="nx">r</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="nx">nums</span><span class="p">[</span><span class="nx">ma</span><span class="p">])</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-4-12" name="__codelineno-4-12" href="#__codelineno-4-12"></a><span class="w"> </span><span class="nx">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">r</span><span class="p">;</span>
<a id="__codelineno-4-13" name="__codelineno-4-13" href="#__codelineno-4-13"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-4-14" name="__codelineno-4-14" href="#__codelineno-4-14"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-4-14" name="__codelineno-4-14" href="#__codelineno-4-14"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-4-15" name="__codelineno-4-15" href="#__codelineno-4-15"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">ma</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="nx">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-4-16" name="__codelineno-4-16" href="#__codelineno-4-16"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-4-17" name="__codelineno-4-17" href="#__codelineno-4-17"></a><span class="w"> </span><span class="p">}</span>
@@ -3686,7 +3686,7 @@
<a id="__codelineno-5-11" name="__codelineno-5-11" href="#__codelineno-5-11"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">n</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="nx">nums</span><span class="p">[</span><span class="nx">r</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="nx">nums</span><span class="p">[</span><span class="nx">ma</span><span class="p">])</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-5-12" name="__codelineno-5-12" href="#__codelineno-5-12"></a><span class="w"> </span><span class="nx">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">r</span><span class="p">;</span>
<a id="__codelineno-5-13" name="__codelineno-5-13" href="#__codelineno-5-13"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-5-14" name="__codelineno-5-14" href="#__codelineno-5-14"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-5-14" name="__codelineno-5-14" href="#__codelineno-5-14"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-5-15" name="__codelineno-5-15" href="#__codelineno-5-15"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">ma</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="nx">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-5-16" name="__codelineno-5-16" href="#__codelineno-5-16"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-5-17" name="__codelineno-5-17" href="#__codelineno-5-17"></a><span class="w"> </span><span class="p">}</span>
@@ -3725,7 +3725,7 @@
<a id="__codelineno-6-9" name="__codelineno-6-9" href="#__codelineno-6-9"></a><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">l</span><span class="p">;</span>
<a id="__codelineno-6-10" name="__codelineno-6-10" href="#__codelineno-6-10"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">n</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">r</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">ma</span><span class="p">])</span>
<a id="__codelineno-6-11" name="__codelineno-6-11" href="#__codelineno-6-11"></a><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">r</span><span class="p">;</span>
<a id="__codelineno-6-12" name="__codelineno-6-12" href="#__codelineno-6-12"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-6-12" name="__codelineno-6-12" href="#__codelineno-6-12"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-6-13" name="__codelineno-6-13" href="#__codelineno-6-13"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">ma</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-6-14" name="__codelineno-6-14" href="#__codelineno-6-14"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-6-15" name="__codelineno-6-15" href="#__codelineno-6-15"></a><span class="w"> </span><span class="p">}</span>
@@ -3768,7 +3768,7 @@
<a id="__codelineno-7-9" name="__codelineno-7-9" href="#__codelineno-7-9"></a><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">l</span><span class="p">;</span>
<a id="__codelineno-7-10" name="__codelineno-7-10" href="#__codelineno-7-10"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">n</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">r</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">ma</span><span class="p">])</span>
<a id="__codelineno-7-11" name="__codelineno-7-11" href="#__codelineno-7-11"></a><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">r</span><span class="p">;</span>
<a id="__codelineno-7-12" name="__codelineno-7-12" href="#__codelineno-7-12"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-7-12" name="__codelineno-7-12" href="#__codelineno-7-12"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-7-13" name="__codelineno-7-13" href="#__codelineno-7-13"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">ma</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">i</span><span class="p">)</span>
<a id="__codelineno-7-14" name="__codelineno-7-14" href="#__codelineno-7-14"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-7-15" name="__codelineno-7-15" href="#__codelineno-7-15"></a><span class="w"> </span><span class="c1">// 交换两节点</span>
@@ -3809,7 +3809,7 @@
<a id="__codelineno-8-12" name="__codelineno-8-12" href="#__codelineno-8-12"></a> <span class="k">if</span> <span class="n">r</span> <span class="o">&lt;</span> <span class="n">n</span><span class="p">,</span> <span class="n">nums</span><span class="p">[</span><span class="n">r</span><span class="p">]</span> <span class="o">&gt;</span> <span class="n">nums</span><span class="p">[</span><span class="n">ma</span><span class="p">]</span> <span class="p">{</span>
<a id="__codelineno-8-13" name="__codelineno-8-13" href="#__codelineno-8-13"></a> <span class="n">ma</span> <span class="p">=</span> <span class="n">r</span>
<a id="__codelineno-8-14" name="__codelineno-8-14" href="#__codelineno-8-14"></a> <span class="p">}</span>
<a id="__codelineno-8-15" name="__codelineno-8-15" href="#__codelineno-8-15"></a> <span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-8-15" name="__codelineno-8-15" href="#__codelineno-8-15"></a> <span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-8-16" name="__codelineno-8-16" href="#__codelineno-8-16"></a> <span class="k">if</span> <span class="n">ma</span> <span class="p">==</span> <span class="n">i</span> <span class="p">{</span>
<a id="__codelineno-8-17" name="__codelineno-8-17" href="#__codelineno-8-17"></a> <span class="k">break</span>
<a id="__codelineno-8-18" name="__codelineno-8-18" href="#__codelineno-8-18"></a> <span class="p">}</span>
@@ -3852,7 +3852,7 @@
<a id="__codelineno-10-7" name="__codelineno-10-7" href="#__codelineno-10-7"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">i</span><span class="p">;</span>
<a id="__codelineno-10-8" name="__codelineno-10-8" href="#__codelineno-10-8"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">l</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">n</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">l</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">ma</span><span class="p">])</span><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">l</span><span class="p">;</span>
<a id="__codelineno-10-9" name="__codelineno-10-9" href="#__codelineno-10-9"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">n</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">r</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">ma</span><span class="p">])</span><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">r</span><span class="p">;</span>
<a id="__codelineno-10-10" name="__codelineno-10-10" href="#__codelineno-10-10"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-10-10" name="__codelineno-10-10" href="#__codelineno-10-10"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-10-11" name="__codelineno-10-11" href="#__codelineno-10-11"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">ma</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-10-12" name="__codelineno-10-12" href="#__codelineno-10-12"></a><span class="w"> </span><span class="c1">// 交换两节点</span>
<a id="__codelineno-10-13" name="__codelineno-10-13" href="#__codelineno-10-13"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">temp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">i</span><span class="p">];</span>
@@ -3895,7 +3895,7 @@
<a id="__codelineno-11-11" name="__codelineno-11-11" href="#__codelineno-11-11"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="n">r</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">n</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">r</span><span class="p">]</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">ma</span><span class="p">]</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-12" name="__codelineno-11-12" href="#__codelineno-11-12"></a><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">r</span><span class="p">;</span>
<a id="__codelineno-11-13" name="__codelineno-11-13" href="#__codelineno-11-13"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-14" name="__codelineno-11-14" href="#__codelineno-11-14"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出</span>
<a id="__codelineno-11-14" name="__codelineno-11-14" href="#__codelineno-11-14"></a><span class="w"> </span><span class="c1">// 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出</span>
<a id="__codelineno-11-15" name="__codelineno-11-15" href="#__codelineno-11-15"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="n">ma</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-16" name="__codelineno-11-16" href="#__codelineno-11-16"></a><span class="w"> </span><span class="k">break</span><span class="p">;</span>
<a id="__codelineno-11-17" name="__codelineno-11-17" href="#__codelineno-11-17"></a><span class="w"> </span><span class="p">}</span>
chapter_sorting/insertion_sort/index.html
+1 -1
View File
@@ -3652,7 +3652,7 @@
</ul>
<h2 id="1143">11.4.3 &nbsp; 插入排序优势<a class="headerlink" href="#1143" title="Permanent link">&para;</a></h2>
<p>插入排序的时间复杂度为 <span class="arithmatex">\(O(n^2)\)</span> ，而我们即将学习的快速排序的时间复杂度为 <span class="arithmatex">\(O(n \log n)\)</span> 。尽管插入排序的时间复杂度相比快速排序更高，<strong>但在数据量较小的情况下，插入排序通常更快</strong>。</p>
<p>这个结论与线性查找和二分查找的适用情况的结论类似。快速排序这类 <span class="arithmatex">\(O(n \log n)\)</span> 的算法属于基于分治的排序算法，往往包含更多单元计算操作。而在数据量较小时，<span class="arithmatex">\(n^2\)</span> 和 <span class="arithmatex">\(n \log n\)</span> 的数值比较接近，复杂度不占主导作用；每轮中的单元计算操作数量起到决定性因素。</p>
<p>这个结论与线性查找和二分查找的适用情况的结论类似。快速排序这类 <span class="arithmatex">\(O(n \log n)\)</span> 的算法属于基于分治的排序算法，往往包含更多单元计算操作。而在数据量较小时，<span class="arithmatex">\(n^2\)</span> 和 <span class="arithmatex">\(n \log n\)</span> 的数值比较接近，复杂度不占主导作用；每轮中的单元操作数量起到决定性因素。</p>
<p>实际上，许多编程语言（例如 Java）的内置排序函数都采用了插入排序，大致思路为：对于长数组，采用基于分治的排序算法，例如快速排序；对于短数组，直接使用插入排序。</p>
<p>虽然冒泡排序、选择排序和插入排序的时间复杂度都为 <span class="arithmatex">\(O(n^2)\)</span> ，但在实际情况中，<strong>插入排序的使用频率显著高于冒泡排序和选择排序</strong>。这是因为：</p>
<ul>
chapter_sorting/merge_sort/index.html
+1 -1
View File
@@ -4037,7 +4037,7 @@
<h2 id="1163">11.6.3 &nbsp; 链表排序 *<a class="headerlink" href="#1163" title="Permanent link">&para;</a></h2>
<p>归并排序在排序链表时具有显著优势，空间复杂度可以优化至 <span class="arithmatex">\(O(1)\)</span> ，原因如下：</p>
<ul>
<li>由于链表仅需改变指针就可实现节点的增删操作，因此合并阶段（将两个短有序链表合并为一个长有序链表）无需创建辅助链表。</li>
<li>由于链表仅需改变指针就可实现节点的增删操作，因此合并阶段（将两个短有序链表合并为一个长有序链表）无须创建辅助链表。</li>
<li>通过使用“迭代划分”替代“递归划分”，可省去递归使用的栈帧空间。</li>
</ul>
<p>具体实现细节比较复杂，有兴趣的同学可以查阅相关资料进行学习。</p>
chapter_sorting/selection_sort/index.html
+1 -1
View File
@@ -3405,7 +3405,7 @@
<li>选取区间 <span class="arithmatex">\([0, n-1]\)</span> 中的最小元素，将其与索引 <span class="arithmatex">\(0\)</span> 处元素交换。完成后，数组前 1 个元素已排序。</li>
<li>选取区间 <span class="arithmatex">\([1, n-1]\)</span> 中的最小元素，将其与索引 <span class="arithmatex">\(1\)</span> 处元素交换。完成后，数组前 2 个元素已排序。</li>
<li>以此类推。经过 <span class="arithmatex">\(n - 1\)</span> 轮选择与交换后，数组前 <span class="arithmatex">\(n - 1\)</span> 个元素已排序。</li>
<li>仅剩的一个元素必定是最大元素，无需排序，因此数组排序完成。</li>
<li>仅剩的一个元素必定是最大元素，无须排序，因此数组排序完成。</li>
</ol>
<div class="tabbed-set tabbed-alternate" data-tabs="1:11"><input checked="checked" id="__tabbed_1_1" name="__tabbed_1" type="radio" /><input id="__tabbed_1_2" name="__tabbed_1" type="radio" /><input id="__tabbed_1_3" name="__tabbed_1" type="radio" /><input id="__tabbed_1_4" name="__tabbed_1" type="radio" /><input id="__tabbed_1_5" name="__tabbed_1" type="radio" /><input id="__tabbed_1_6" name="__tabbed_1" type="radio" /><input id="__tabbed_1_7" name="__tabbed_1" type="radio" /><input id="__tabbed_1_8" name="__tabbed_1" type="radio" /><input id="__tabbed_1_9" name="__tabbed_1" type="radio" /><input id="__tabbed_1_10" name="__tabbed_1" type="radio" /><input id="__tabbed_1_11" name="__tabbed_1" type="radio" /><div class="tabbed-labels"><label for="__tabbed_1_1">&lt;1&gt;</label><label for="__tabbed_1_2">&lt;2&gt;</label><label for="__tabbed_1_3">&lt;3&gt;</label><label for="__tabbed_1_4">&lt;4&gt;</label><label for="__tabbed_1_5">&lt;5&gt;</label><label for="__tabbed_1_6">&lt;6&gt;</label><label for="__tabbed_1_7">&lt;7&gt;</label><label for="__tabbed_1_8">&lt;8&gt;</label><label for="__tabbed_1_9">&lt;9&gt;</label><label for="__tabbed_1_10">&lt;10&gt;</label><label for="__tabbed_1_11">&lt;11&gt;</label></div>
<div class="tabbed-content">
chapter_sorting/sorting_algorithm/index.html
+1 -1
View File
@@ -3419,7 +3419,7 @@
<h2 id="1111">11.1.1 &nbsp; 评价维度<a class="headerlink" href="#1111" title="Permanent link">&para;</a></h2>
<p><strong>运行效率</strong>：我们期望排序算法的时间复杂度尽量低，且总体操作数量较少（即时间复杂度中的常数项降低）。对于大数据量情况，运行效率显得尤为重要。</p>
<p><strong>就地性</strong>：顾名思义，「原地排序」通过在原数组上直接操作实现排序，无需借助额外的辅助数组，从而节省内存。通常情况下，原地排序的数据搬运操作较少，运行速度也更快。</p>
<p><strong>就地性</strong>：顾名思义，「原地排序」通过在原数组上直接操作实现排序，无须借助额外的辅助数组，从而节省内存。通常情况下，原地排序的数据搬运操作较少，运行速度也更快。</p>
<p><strong>稳定性</strong>：「稳定排序」在完成排序后，相等元素在数组中的相对顺序不发生改变。稳定排序是优良特性，也是多级排序场景的必要条件。</p>
<p>假设我们有一个存储学生信息的表格，第 1, 2 列分别是姓名和年龄。在这种情况下，「非稳定排序」可能导致输入数据的有序性丧失。</p>
<div class="highlight"><pre><span></span><code><a id="__codelineno-0-1" name="__codelineno-0-1" href="#__codelineno-0-1"></a><span class="c1"># 输入数据是按照姓名排序好的</span>
chapter_stack_and_queue/stack/index.html
+1 -1
View File
@@ -4583,7 +4583,7 @@
</div>
<p align="center"> 图：基于数组实现栈的入栈出栈操作 </p>
<p>由于入栈的元素可能会源源不断地增加，因此我们可以使用动态数组，这样就无需自行处理数组扩容问题。以下为示例代码。</p>
<p>由于入栈的元素可能会源源不断地增加，因此我们可以使用动态数组，这样就无须自行处理数组扩容问题。以下为示例代码。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="5:12"><input checked="checked" id="__tabbed_5_1" name="__tabbed_5" type="radio" /><input id="__tabbed_5_2" name="__tabbed_5" type="radio" /><input id="__tabbed_5_3" name="__tabbed_5" type="radio" /><input id="__tabbed_5_4" name="__tabbed_5" type="radio" /><input id="__tabbed_5_5" name="__tabbed_5" type="radio" /><input id="__tabbed_5_6" name="__tabbed_5" type="radio" /><input id="__tabbed_5_7" name="__tabbed_5" type="radio" /><input id="__tabbed_5_8" name="__tabbed_5" type="radio" /><input id="__tabbed_5_9" name="__tabbed_5" type="radio" /><input id="__tabbed_5_10" name="__tabbed_5" type="radio" /><input id="__tabbed_5_11" name="__tabbed_5" type="radio" /><input id="__tabbed_5_12" name="__tabbed_5" type="radio" /><div class="tabbed-labels"><label for="__tabbed_5_1">Java</label><label for="__tabbed_5_2">C++</label><label for="__tabbed_5_3">Python</label><label for="__tabbed_5_4">Go</label><label for="__tabbed_5_5">JS</label><label for="__tabbed_5_6">TS</label><label for="__tabbed_5_7">C</label><label for="__tabbed_5_8">C#</label><label for="__tabbed_5_9">Swift</label><label for="__tabbed_5_10">Zig</label><label for="__tabbed_5_11">Dart</label><label for="__tabbed_5_12">Rust</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
chapter_tree/avl_tree/index.html
+12 -12
View File
@@ -4640,7 +4640,7 @@
<a id="__codelineno-60-24" name="__codelineno-60-24" href="#__codelineno-60-24"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">leftRotate</span><span class="p">(</span><span class="n">node</span><span class="p">);</span>
<a id="__codelineno-60-25" name="__codelineno-60-25" href="#__codelineno-60-25"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-60-26" name="__codelineno-60-26" href="#__codelineno-60-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-60-27" name="__codelineno-60-27" href="#__codelineno-60-27"></a><span class="w"> </span><span class="c1">// 平衡树，无需旋转，直接返回</span>
<a id="__codelineno-60-27" name="__codelineno-60-27" href="#__codelineno-60-27"></a><span class="w"> </span><span class="c1">// 平衡树，无须旋转，直接返回</span>
<a id="__codelineno-60-28" name="__codelineno-60-28" href="#__codelineno-60-28"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-60-29" name="__codelineno-60-29" href="#__codelineno-60-29"></a><span class="p">}</span>
</code></pre></div>
@@ -4672,7 +4672,7 @@
<a id="__codelineno-61-24" name="__codelineno-61-24" href="#__codelineno-61-24"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">leftRotate</span><span class="p">(</span><span class="n">node</span><span class="p">);</span>
<a id="__codelineno-61-25" name="__codelineno-61-25" href="#__codelineno-61-25"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-61-26" name="__codelineno-61-26" href="#__codelineno-61-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-61-27" name="__codelineno-61-27" href="#__codelineno-61-27"></a><span class="w"> </span><span class="c1">// 平衡树，无需旋转，直接返回</span>
<a id="__codelineno-61-27" name="__codelineno-61-27" href="#__codelineno-61-27"></a><span class="w"> </span><span class="c1">// 平衡树，无须旋转，直接返回</span>
<a id="__codelineno-61-28" name="__codelineno-61-28" href="#__codelineno-61-28"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-61-29" name="__codelineno-61-29" href="#__codelineno-61-29"></a><span class="p">}</span>
</code></pre></div>
@@ -4700,7 +4700,7 @@
<a id="__codelineno-62-20" name="__codelineno-62-20" href="#__codelineno-62-20"></a> <span class="c1"># 先右旋后左旋</span>
<a id="__codelineno-62-21" name="__codelineno-62-21" href="#__codelineno-62-21"></a> <span class="n">node</span><span class="o">.</span><span class="n">right</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">__right_rotate</span><span class="p">(</span><span class="n">node</span><span class="o">.</span><span class="n">right</span><span class="p">)</span>
<a id="__codelineno-62-22" name="__codelineno-62-22" href="#__codelineno-62-22"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">__left_rotate</span><span class="p">(</span><span class="n">node</span><span class="p">)</span>
<a id="__codelineno-62-23" name="__codelineno-62-23" href="#__codelineno-62-23"></a> <span class="c1"># 平衡树，无需旋转，直接返回</span>
<a id="__codelineno-62-23" name="__codelineno-62-23" href="#__codelineno-62-23"></a> <span class="c1"># 平衡树，无须旋转，直接返回</span>
<a id="__codelineno-62-24" name="__codelineno-62-24" href="#__codelineno-62-24"></a> <span class="k">return</span> <span class="n">node</span>
</code></pre></div>
</div>
@@ -4732,7 +4732,7 @@
<a id="__codelineno-63-25" name="__codelineno-63-25" href="#__codelineno-63-25"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">t</span><span class="p">.</span><span class="nx">leftRotate</span><span class="p">(</span><span class="nx">node</span><span class="p">)</span>
<a id="__codelineno-63-26" name="__codelineno-63-26" href="#__codelineno-63-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-63-27" name="__codelineno-63-27" href="#__codelineno-63-27"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-63-28" name="__codelineno-63-28" href="#__codelineno-63-28"></a><span class="w"> </span><span class="c1">// 平衡树，无需旋转，直接返回</span>
<a id="__codelineno-63-28" name="__codelineno-63-28" href="#__codelineno-63-28"></a><span class="w"> </span><span class="c1">// 平衡树，无须旋转，直接返回</span>
<a id="__codelineno-63-29" name="__codelineno-63-29" href="#__codelineno-63-29"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">node</span>
<a id="__codelineno-63-30" name="__codelineno-63-30" href="#__codelineno-63-30"></a><span class="p">}</span>
</code></pre></div>
@@ -4764,7 +4764,7 @@
<a id="__codelineno-64-24" name="__codelineno-64-24" href="#__codelineno-64-24"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">leftRotate</span><span class="p">(</span><span class="nx">node</span><span class="p">);</span>
<a id="__codelineno-64-25" name="__codelineno-64-25" href="#__codelineno-64-25"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-64-26" name="__codelineno-64-26" href="#__codelineno-64-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-64-27" name="__codelineno-64-27" href="#__codelineno-64-27"></a><span class="w"> </span><span class="c1">// 平衡树，无需旋转，直接返回</span>
<a id="__codelineno-64-27" name="__codelineno-64-27" href="#__codelineno-64-27"></a><span class="w"> </span><span class="c1">// 平衡树，无须旋转，直接返回</span>
<a id="__codelineno-64-28" name="__codelineno-64-28" href="#__codelineno-64-28"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-64-29" name="__codelineno-64-29" href="#__codelineno-64-29"></a><span class="p">}</span>
</code></pre></div>
@@ -4796,7 +4796,7 @@
<a id="__codelineno-65-24" name="__codelineno-65-24" href="#__codelineno-65-24"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">leftRotate</span><span class="p">(</span><span class="nx">node</span><span class="p">);</span>
<a id="__codelineno-65-25" name="__codelineno-65-25" href="#__codelineno-65-25"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-65-26" name="__codelineno-65-26" href="#__codelineno-65-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-65-27" name="__codelineno-65-27" href="#__codelineno-65-27"></a><span class="w"> </span><span class="c1">// 平衡树，无需旋转，直接返回</span>
<a id="__codelineno-65-27" name="__codelineno-65-27" href="#__codelineno-65-27"></a><span class="w"> </span><span class="c1">// 平衡树，无须旋转，直接返回</span>
<a id="__codelineno-65-28" name="__codelineno-65-28" href="#__codelineno-65-28"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-65-29" name="__codelineno-65-29" href="#__codelineno-65-29"></a><span class="p">}</span>
</code></pre></div>
@@ -4828,7 +4828,7 @@
<a id="__codelineno-66-24" name="__codelineno-66-24" href="#__codelineno-66-24"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">leftRotate</span><span class="p">(</span><span class="n">node</span><span class="p">);</span>
<a id="__codelineno-66-25" name="__codelineno-66-25" href="#__codelineno-66-25"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-66-26" name="__codelineno-66-26" href="#__codelineno-66-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-66-27" name="__codelineno-66-27" href="#__codelineno-66-27"></a><span class="w"> </span><span class="c1">// 平衡树，无需旋转，直接返回</span>
<a id="__codelineno-66-27" name="__codelineno-66-27" href="#__codelineno-66-27"></a><span class="w"> </span><span class="c1">// 平衡树，无须旋转，直接返回</span>
<a id="__codelineno-66-28" name="__codelineno-66-28" href="#__codelineno-66-28"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-66-29" name="__codelineno-66-29" href="#__codelineno-66-29"></a><span class="p">}</span>
</code></pre></div>
@@ -4860,7 +4860,7 @@
<a id="__codelineno-67-24" name="__codelineno-67-24" href="#__codelineno-67-24"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nf">leftRotate</span><span class="p">(</span><span class="n">node</span><span class="p">);</span>
<a id="__codelineno-67-25" name="__codelineno-67-25" href="#__codelineno-67-25"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-67-26" name="__codelineno-67-26" href="#__codelineno-67-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-67-27" name="__codelineno-67-27" href="#__codelineno-67-27"></a><span class="w"> </span><span class="c1">// 平衡树，无需旋转，直接返回</span>
<a id="__codelineno-67-27" name="__codelineno-67-27" href="#__codelineno-67-27"></a><span class="w"> </span><span class="c1">// 平衡树，无须旋转，直接返回</span>
<a id="__codelineno-67-28" name="__codelineno-67-28" href="#__codelineno-67-28"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-67-29" name="__codelineno-67-29" href="#__codelineno-67-29"></a><span class="p">}</span>
</code></pre></div>
@@ -4892,7 +4892,7 @@
<a id="__codelineno-68-24" name="__codelineno-68-24" href="#__codelineno-68-24"></a> <span class="k">return</span> <span class="n">leftRotate</span><span class="p">(</span><span class="n">node</span><span class="p">:</span> <span class="n">node</span><span class="p">)</span>
<a id="__codelineno-68-25" name="__codelineno-68-25" href="#__codelineno-68-25"></a> <span class="p">}</span>
<a id="__codelineno-68-26" name="__codelineno-68-26" href="#__codelineno-68-26"></a> <span class="p">}</span>
<a id="__codelineno-68-27" name="__codelineno-68-27" href="#__codelineno-68-27"></a> <span class="c1">// 平衡树，无需旋转，直接返回</span>
<a id="__codelineno-68-27" name="__codelineno-68-27" href="#__codelineno-68-27"></a> <span class="c1">// 平衡树，无须旋转，直接返回</span>
<a id="__codelineno-68-28" name="__codelineno-68-28" href="#__codelineno-68-28"></a> <span class="k">return</span> <span class="n">node</span>
<a id="__codelineno-68-29" name="__codelineno-68-29" href="#__codelineno-68-29"></a><span class="p">}</span>
</code></pre></div>
@@ -4924,7 +4924,7 @@
<a id="__codelineno-69-24" name="__codelineno-69-24" href="#__codelineno-69-24"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">leftRotate</span><span class="p">(</span><span class="n">node</span><span class="p">);</span>
<a id="__codelineno-69-25" name="__codelineno-69-25" href="#__codelineno-69-25"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-69-26" name="__codelineno-69-26" href="#__codelineno-69-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-69-27" name="__codelineno-69-27" href="#__codelineno-69-27"></a><span class="w"> </span><span class="c1">// 平衡树，无需旋转，直接返回</span>
<a id="__codelineno-69-27" name="__codelineno-69-27" href="#__codelineno-69-27"></a><span class="w"> </span><span class="c1">// 平衡树，无须旋转，直接返回</span>
<a id="__codelineno-69-28" name="__codelineno-69-28" href="#__codelineno-69-28"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-69-29" name="__codelineno-69-29" href="#__codelineno-69-29"></a><span class="p">}</span>
</code></pre></div>
@@ -4956,7 +4956,7 @@
<a id="__codelineno-70-24" name="__codelineno-70-24" href="#__codelineno-70-24"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">leftRotate</span><span class="p">(</span><span class="n">node</span><span class="p">);</span>
<a id="__codelineno-70-25" name="__codelineno-70-25" href="#__codelineno-70-25"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-70-26" name="__codelineno-70-26" href="#__codelineno-70-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-70-27" name="__codelineno-70-27" href="#__codelineno-70-27"></a><span class="w"> </span><span class="c1">// 平衡树，无需旋转，直接返回</span>
<a id="__codelineno-70-27" name="__codelineno-70-27" href="#__codelineno-70-27"></a><span class="w"> </span><span class="c1">// 平衡树，无须旋转，直接返回</span>
<a id="__codelineno-70-28" name="__codelineno-70-28" href="#__codelineno-70-28"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-70-29" name="__codelineno-70-29" href="#__codelineno-70-29"></a><span class="p">}</span>
</code></pre></div>
@@ -4992,7 +4992,7 @@
<a id="__codelineno-71-28" name="__codelineno-71-28" href="#__codelineno-71-28"></a><span class="w"> </span><span class="bp">Self</span>::<span class="n">left_rotate</span><span class="p">(</span><span class="nb">Some</span><span class="p">(</span><span class="n">node</span><span class="p">))</span>
<a id="__codelineno-71-29" name="__codelineno-71-29" href="#__codelineno-71-29"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-71-30" name="__codelineno-71-30" href="#__codelineno-71-30"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-71-31" name="__codelineno-71-31" href="#__codelineno-71-31"></a><span class="w"> </span><span class="c1">// 平衡树，无需旋转，直接返回</span>
<a id="__codelineno-71-31" name="__codelineno-71-31" href="#__codelineno-71-31"></a><span class="w"> </span><span class="c1">// 平衡树，无须旋转，直接返回</span>
<a id="__codelineno-71-32" name="__codelineno-71-32" href="#__codelineno-71-32"></a><span class="w"> </span><span class="n">node</span>
<a id="__codelineno-71-33" name="__codelineno-71-33" href="#__codelineno-71-33"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-71-34" name="__codelineno-71-34" href="#__codelineno-71-34"></a><span class="p">}</span>
chapter_tree/binary_search_tree/index.html
+1 -1
View File
@@ -4900,7 +4900,7 @@ void insert(int num) {
</div>
<h3 id="4">4. &nbsp; 排序<a class="headerlink" href="#4" title="Permanent link">&para;</a></h3>
<p>我们知道，二叉树的中序遍历遵循“左 <span class="arithmatex">\(\rightarrow\)</span> 根 <span class="arithmatex">\(\rightarrow\)</span> 右”的遍历顺序，而二叉搜索树满足“左子节点 <span class="arithmatex">\(&lt;\)</span> 根节点 <span class="arithmatex">\(&lt;\)</span> 右子节点”的大小关系。因此，在二叉搜索树中进行中序遍历时，总是会优先遍历下一个最小节点，从而得出一个重要性质：<strong>二叉搜索树的中序遍历序列是升序的</strong>。</p>
<p>利用中序遍历升序的性质，我们在二叉搜索树中获取有序数据仅需 <span class="arithmatex">\(O(n)\)</span> 时间，无需额外排序，非常高效。</p>
<p>利用中序遍历升序的性质，我们在二叉搜索树中获取有序数据仅需 <span class="arithmatex">\(O(n)\)</span> 时间，无须额外排序，非常高效。</p>
<p><img alt="二叉搜索树的中序遍历序列" src="../binary_search_tree.assets/bst_inorder_traversal.png" /></p>
<p align="center"> 图：二叉搜索树的中序遍历序列 </p>
search/search_index.json
+1 -1
View File
File diff suppressed because one or more lines are too long
sitemap.xml.gz
BIN
View File
Binary file not shown.