This commit is contained in:
krahets
2023-09-21 20:44:52 +08:00
parent 830dc9e326
commit 0ba5acd92b
111 changed files with 13161 additions and 5302 deletions
+125 -46
View File
@@ -3458,7 +3458,32 @@
<div class="md-content" data-md-component="content">
<article class="md-content__inner md-typeset">
<!--
Copyright (c) 2016-2023 Martin Donath <martin.donath@squidfunk.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.
-->
<!-- Tags -->
<!-- Actions -->
<a href="https://github.com/krahets/hello-algo/tree/main/docs/chapter_hashing/hash_algorithm.md" title="编辑此页" class="md-content__button md-icon">
@@ -3469,11 +3494,18 @@
<!--
Hack: check whether the content contains a h1 headline. If it doesn't, the
page title (or respectively site name) is used as the main headline.
-->
<!-- Page content -->
<h1 id="63">6.3 &nbsp; 哈希算法<a class="headerlink" href="#63" title="Permanent link">&para;</a></h1>
<p>在上两节中,我们了解了哈希表的工作原理和哈希冲突的处理方法。然而无论是开放寻址还是链地址法,<strong>它们只能保证哈希表可以在发生冲突时正常工作,但无法减少哈希冲突的发生</strong></p>
<p>如果哈希冲突过于频繁,哈希表的性能则会急剧劣化。如图 6-7 所示,对于链地址哈希表,理想情况下键值对平均分布在各个桶中,达到最佳查询效率;最差情况下所有键值对都被存储到同一个桶中,时间复杂度退化至 <span class="arithmatex">\(O(n)\)</span></p>
<p>如果哈希冲突过于频繁,哈希表的性能则会急剧劣化。如图 6-8 所示,对于链地址哈希表,理想情况下键值对平均分布在各个桶中,达到最佳查询效率;最差情况下所有键值对都被存储到同一个桶中,时间复杂度退化至 <span class="arithmatex">\(O(n)\)</span></p>
<p><img alt="哈希冲突的最佳与最差情况" src="../hash_algorithm.assets/hash_collision_best_worst_condition.png" /></p>
<p align="center"> 图 6-7 &nbsp; 哈希冲突的最佳与最差情况 </p>
<p align="center"> 图 6-8 &nbsp; 哈希冲突的最佳与最差情况 </p>
<p><strong>键值对的分布情况由哈希函数决定</strong>。回忆哈希函数的计算步骤,先计算哈希值,再对数组长度取模:</p>
<div class="highlight"><pre><span></span><code><a id="__codelineno-0-1" name="__codelineno-0-1" href="#__codelineno-0-1"></a><span class="nv">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span>hash<span class="o">(</span>key<span class="o">)</span><span class="w"> </span>%<span class="w"> </span>capacity
@@ -4276,11 +4308,73 @@
<p>虽然自定义对象(比如链表节点)的成员变量是可变的,但它是可哈希的。<strong>这是因为对象的哈希值通常是基于内存地址生成的</strong>,即使对象的内容发生了变化,但它的内存地址不变,哈希值仍然是不变的。</p>
<p>细心的你可能发现在不同控制台中运行程序时,输出的哈希值是不同的。<strong>这是因为 Python 解释器在每次启动时,都会为字符串哈希函数加入一个随机的盐(Salt)值</strong>。这种做法可以有效防止 HashDoS 攻击,提升哈希算法的安全性。</p>
<!-- Source file information -->
<!-- Was this page helpful? -->
<h2 id="__comments">评论</h2>
<!-- Previous and next pages link -->
<nav
class="md-footer__inner md-grid"
aria-label="页脚"
>
<!-- Link to previous page -->
<a
href="../hash_collision/"
class="md-footer__link md-footer__link--prev"
aria-label="上一页: 6.2 &amp;nbsp; 哈希冲突"
rel="prev"
>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</div>
<div class="md-footer__title">
<span class="md-footer__direction">
上一页
</span>
<div class="md-ellipsis">
6.2 &nbsp; 哈希冲突
</div>
</div>
</a>
<!-- Link to next page -->
<a
href="../summary/"
class="md-footer__link md-footer__link--next"
aria-label="下一页: 6.4 &amp;nbsp; 小结"
rel="next"
>
<div class="md-footer__title">
<span class="md-footer__direction">
下一页
</span>
<div class="md-ellipsis">
6.4 &nbsp; 小结
</div>
</div>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11H4Z"/></svg>
</div>
</a>
</nav>
<!-- Comment system -->
<h5 align="center" id="__comments">欢迎你提出疑问或建议</h5>
<!-- Insert generated snippet here -->
<script
src="https://giscus.app/client.js"
@@ -4346,48 +4440,31 @@
</main>
<footer class="md-footer">
<nav class="md-footer__inner md-grid" aria-label="页脚" >
<a href="../hash_collision/" class="md-footer__link md-footer__link--prev" aria-label="上一页: 6.2 &amp;nbsp; 哈希冲突" rel="prev">
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</div>
<div class="md-footer__title">
<span class="md-footer__direction">
上一页
</span>
<div class="md-ellipsis">
6.2 &nbsp; 哈希冲突
</div>
</div>
</a>
<a href="../summary/" class="md-footer__link md-footer__link--next" aria-label="下一页: 6.4 &amp;nbsp; 小结" rel="next">
<div class="md-footer__title">
<span class="md-footer__direction">
下一页
</span>
<div class="md-ellipsis">
6.4 &nbsp; 小结
</div>
</div>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11H4Z"/></svg>
</div>
</a>
</nav>
<!--
Copyright (c) 2016-2023 Martin Donath <martin.donath@squidfunk.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.
-->
<!-- Footer -->
<footer class="md-footer">
<!-- Further information -->
<div class="md-footer-meta md-typeset">
<div class="md-footer-meta__inner md-grid">
<div class="md-copyright">
@@ -4398,6 +4475,8 @@
</div>
<!-- Social links -->
<div class="md-social">
Binary file not shown.

After

Width:  |  Height:  |  Size: 58 KiB

+509 -364
View File
@@ -1303,7 +1303,14 @@
<li class="md-nav__item">
<a href="#2" class="md-nav__link">
2. &nbsp; 多次哈希
2. &nbsp; 平方探测
</a>
</li>
<li class="md-nav__item">
<a href="#3" class="md-nav__link">
3. &nbsp; 多次哈希
</a>
</li>
@@ -3455,7 +3462,14 @@
<li class="md-nav__item">
<a href="#2" class="md-nav__link">
2. &nbsp; 多次哈希
2. &nbsp; 平方探测
</a>
</li>
<li class="md-nav__item">
<a href="#3" class="md-nav__link">
3. &nbsp; 多次哈希
</a>
</li>
@@ -3484,7 +3498,32 @@
<div class="md-content" data-md-component="content">
<article class="md-content__inner md-typeset">
<!--
Copyright (c) 2016-2023 Martin Donath <martin.donath@squidfunk.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.
-->
<!-- Tags -->
<!-- Actions -->
<a href="https://github.com/krahets/hello-algo/tree/main/docs/chapter_hashing/hash_collision.md" title="编辑此页" class="md-content__button md-icon">
@@ -3495,8 +3534,15 @@
<!--
Hack: check whether the content contains a h1 headline. If it doesn't, the
page title (or respectively site name) is used as the main headline.
-->
<!-- Page content -->
<h1 id="62">6.2 &nbsp; 哈希冲突<a class="headerlink" href="#62" title="Permanent link">&para;</a></h1>
<p>上节提到,<strong>通常情况下哈希函数的输入空间远大于输出空间</strong>,因此理论上哈希冲突是不可避免的。比如,输入空间为全体整数,输出空间为数组容量大小,则必然有多个整数映射至同一数组索引。</p>
<p>上节提到,<strong>通常情况下哈希函数的输入空间远大于输出空间</strong>,因此理论上哈希冲突是不可避免的。比如,输入空间为全体整数,输出空间为数组容量大小,则必然有多个整数映射至同一索引。</p>
<p>哈希冲突会导致查询结果错误,严重影响哈希表的可用性。为解决该问题,我们可以每当遇到哈希冲突时就进行哈希表扩容,直至冲突消失为止。此方法简单粗暴且有效,但效率太低,因为哈希表扩容需要进行大量的数据搬运与哈希值计算。为了提升效率,我们可以采用以下策略。</p>
<ol>
<li>改良哈希表数据结构,<strong>使得哈希表可以在存在哈希冲突时正常工作</strong></li>
@@ -3508,9 +3554,9 @@
<p><img alt="链式地址哈希表" src="../hash_collision.assets/hash_table_chaining.png" /></p>
<p align="center"> 图 6-5 &nbsp; 链式地址哈希表 </p>
<p>哈希表在链式地址下的操作方法发生了一些变化。</p>
<p>基于链式地址实现的哈希表的操作方法发生了以下变化。</p>
<ul>
<li><strong>查询元素</strong>:输入 <code>key</code> ,经过哈希函数得到数组索引,即可访问链表头节点,然后遍历链表并对比 <code>key</code> 以查找目标键值对。</li>
<li><strong>查询元素</strong>:输入 <code>key</code> ,经过哈希函数得到索引,即可访问链表头节点,然后遍历链表并对比 <code>key</code> 以查找目标键值对。</li>
<li><strong>添加元素</strong>:先通过哈希函数访问链表头节点,然后将节点(即键值对)添加到链表中。</li>
<li><strong>删除元素</strong>:根据哈希函数的结果访问链表头部,接着遍历链表以查找目标节点,并将其删除。</li>
</ul>
@@ -4800,26 +4846,26 @@
<p>值得注意的是,当链表很长时,查询效率 <span class="arithmatex">\(O(n)\)</span> 很差。<strong>此时可以将链表转换为“AVL 树”或“红黑树”</strong>,从而将查询操作的时间复杂度优化至 <span class="arithmatex">\(O(\log n)\)</span></p>
<h2 id="622">6.2.2 &nbsp; 开放寻址<a class="headerlink" href="#622" title="Permanent link">&para;</a></h2>
<p>「开放寻址 open addressing」不引入额外的数据结构,而是通过“多次探测”来处理哈希冲突,探测方式主要包括线性探测、平方探测、多次哈希等。</p>
<p>下面将主要以线性探测为例,介绍开放寻址哈希表的工作机制与代码实现。</p>
<h3 id="1">1. &nbsp; 线性探测<a class="headerlink" href="#1" title="Permanent link">&para;</a></h3>
<p>线性探测采用固定步长的线性搜索来进行探测,其操作方法与普通哈希表有所不同。</p>
<ul>
<li><strong>插入元素</strong>:通过哈希函数计算数组索引,若发现桶内已有元素,则从冲突位置向后线性遍历(步长通常为 <span class="arithmatex">\(1\)</span> ),直至找到空,将元素插入其中。</li>
<li><strong>查找元素</strong>:若发现哈希冲突,则使用相同步长向后线性遍历,直到找到对应元素,返回 <code>value</code> 即可;如果遇到空,说明目标键值对不在哈希表中,返回 <span class="arithmatex">\(\text{None}\)</span></li>
<li><strong>插入元素</strong>:通过哈希函数计算索引,若发现桶内已有元素,则从冲突位置向后线性遍历(步长通常为 <span class="arithmatex">\(1\)</span> ),直至找到空,将元素插入其中。</li>
<li><strong>查找元素</strong>:若发现哈希冲突,则使用相同步长向后线性遍历,直到找到对应元素,返回 <code>value</code> 即可;如果遇到空,说明目标元素不在哈希表中,返回 <span class="arithmatex">\(\text{None}\)</span></li>
</ul>
<p>图 6-6 展示了一个在开放寻址(线性探测)下工作的哈希表。</p>
<p>图 6-6 展示了开放寻址(线性探测)哈希表的键值对分布。根据此哈希函数,最后两位相同的 <code>key</code> 都会被映射到相同的桶。而通过线性探测,它们被依次存储在该桶以及之下的桶中</p>
<p><img alt="开放寻址和线性探测" src="../hash_collision.assets/hash_table_linear_probing.png" /></p>
<p align="center"> 图 6-6 &nbsp; 开放寻址和线性探测 </p>
<p>然而,线性探测存在以下缺陷</p>
<ul>
<li><strong>不能直接删除元素</strong>。删除元素会在数组内产生一个空位,当查找该空位之后的元素时,该空位可能导致程序误判元素不存在。为此,通常需要借助一个标志位来标记已删除元素。</li>
<li><strong>容易产生聚集</strong>。数组内连续被占用位置越长,这些连续位置发生哈希冲突的可能性越大,进一步促使这一位置的聚堆生长,形成恶性循环,最终导致增删查改操作效率劣化。</li>
</ul>
<p>以下代码实现了一个简单的开放寻址(线性探测)哈希表</p>
<ul>
<li>我们使用一个固定的键值对实例 <code>removed</code> 来标记已删除元素。也就是说,当一个桶内的元素为 <span class="arithmatex">\(\text{None}\)</span><code>removed</code> 时,说明这个桶是空的,可用于放置键值对</li>
<li>在线性探测时,我们从当前索引 <code>index</code> 向后遍历;而当越过数组尾部时,需要回到头部继续遍历。</li>
</ul>
<p>然而,<strong>线性探测容易产生“聚集现象”</strong>。具体来说,数组中连续被占用的位置越长,这些连续位置发生哈希冲突的可能性越大,从而进一步促使该位置的聚堆生长,形成恶性循环,最终导致增删查改操作效率劣化</p>
<p>值得注意的是,<strong>我们不能在开放寻址哈希表中直接删除元素</strong>。这是因为删除元素会在数组内产生一个空桶 <span class="arithmatex">\(\text{None}\)</span> ,而当查询元素时,线性探测到该空桶就会返回,因此在该空桶之下的元素都无法再被访问到,程序可能误判这些元素不存在。</p>
<p><img alt="在开放寻址中删除元素导致的查询问题" src="../hash_collision.assets/hash_table_open_addressing_deletion.png" /></p>
<p align="center"> 图 6-7 &nbsp; 在开放寻址中删除元素导致的查询问题 </p>
<p>为了解决该问题,我们可以采用「懒删除 lazy deletion」机制:它不直接从哈希表中移除元素,<strong>而是利用一个常量 <code>TOMBSTONE</code> 来标记这个桶</strong>。在该机制下,<span class="arithmatex">\(\text{None}\)</span><code>TOMBSTONE</code> 都代表空桶,都可以放置键值对。但不同的是,线性探测到 <code>TOMBSTONE</code> 时应该继续遍历,因为其之下可能还存在键值对</p>
<p>然而,<strong>懒删除可能会加速哈希表的性能退化</strong>。这是因为每次删除操作都会产生一个删除标记,随着 <code>TOMBSTONE</code> 的增加,搜索时间也会增加,因为线性探测可能需要跳过多个 <code>TOMBSTONE</code> 才能找到目标元素。</p>
<p>为此,考虑在线性探测中记录遇到的首个 <code>TOMBSTONE</code> 的索引,并将搜索到的目标元素与该 <code>TOMBSTONE</code> 交换位置。这样做的好处是当每次查询或添加元素时,元素会被移动至距离理想位置(探测起始点)更近的桶,从而优化查询效率</p>
<p>以下代码实现了一个包含懒删除的开放寻址(线性探测)哈希表。为了更加充分地使用哈希表的空间,我们将哈希表表看作是一个“环形数组”,当越过数组尾部时,回到头部继续遍历。</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">Python</label><label for="__tabbed_2_2">C++</label><label for="__tabbed_2_3">Java</label><label for="__tabbed_2_4">C#</label><label for="__tabbed_2_5">Go</label><label for="__tabbed_2_6">Swift</label><label for="__tabbed_2_7">JS</label><label for="__tabbed_2_8">TS</label><label for="__tabbed_2_9">Dart</label><label for="__tabbed_2_10">Rust</label><label for="__tabbed_2_11">C</label><label for="__tabbed_2_12">Zig</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
@@ -4833,7 +4879,7 @@
<a id="__codelineno-12-8" name="__codelineno-12-8" href="#__codelineno-12-8"></a> <span class="bp">self</span><span class="o">.</span><span class="n">load_thres</span> <span class="o">=</span> <span class="mi">2</span> <span class="o">/</span> <span class="mi">3</span> <span class="c1"># 触发扩容的负载因子阈值</span>
<a id="__codelineno-12-9" name="__codelineno-12-9" href="#__codelineno-12-9"></a> <span class="bp">self</span><span class="o">.</span><span class="n">extend_ratio</span> <span class="o">=</span> <span class="mi">2</span> <span class="c1"># 扩容倍数</span>
<a id="__codelineno-12-10" name="__codelineno-12-10" href="#__codelineno-12-10"></a> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">:</span> <span class="nb">list</span><span class="p">[</span><span class="n">Pair</span> <span class="o">|</span> <span class="kc">None</span><span class="p">]</span> <span class="o">=</span> <span class="p">[</span><span class="kc">None</span><span class="p">]</span> <span class="o">*</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span> <span class="c1"># 桶数组</span>
<a id="__codelineno-12-11" name="__codelineno-12-11" href="#__codelineno-12-11"></a> <span class="bp">self</span><span class="o">.</span><span class="n">removed</span> <span class="o">=</span> <span class="n">Pair</span><span class="p">(</span><span class="o">-</span><span class="mi">1</span><span class="p">,</span> <span class="s2">&quot;-1&quot;</span><span class="p">)</span> <span class="c1"># 删除标记</span>
<a id="__codelineno-12-11" name="__codelineno-12-11" href="#__codelineno-12-11"></a> <span class="bp">self</span><span class="o">.</span><span class="n">TOMBSTONE</span> <span class="o">=</span> <span class="n">Pair</span><span class="p">(</span><span class="o">-</span><span class="mi">1</span><span class="p">,</span> <span class="s2">&quot;-1&quot;</span><span class="p">)</span> <span class="c1"># 删除标记</span>
<a id="__codelineno-12-12" name="__codelineno-12-12" href="#__codelineno-12-12"></a>
<a id="__codelineno-12-13" name="__codelineno-12-13" href="#__codelineno-12-13"></a> <span class="k">def</span> <span class="nf">hash_func</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">key</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</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="sd">&quot;&quot;&quot;哈希函数&quot;&quot;&quot;</span>
@@ -4843,320 +4889,353 @@
<a id="__codelineno-12-18" name="__codelineno-12-18" href="#__codelineno-12-18"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;负载因子&quot;&quot;&quot;</span>
<a id="__codelineno-12-19" name="__codelineno-12-19" href="#__codelineno-12-19"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">size</span> <span class="o">/</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span>
<a id="__codelineno-12-20" name="__codelineno-12-20" href="#__codelineno-12-20"></a>
<a id="__codelineno-12-21" name="__codelineno-12-21" href="#__codelineno-12-21"></a> <span class="k">def</span> <span class="nf">get</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">key</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">str</span><span class="p">:</span>
<a id="__codelineno-12-22" name="__codelineno-12-22" href="#__codelineno-12-22"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;查询操作&quot;&quot;&quot;</span>
<a id="__codelineno-12-21" name="__codelineno-12-21" href="#__codelineno-12-21"></a> <span class="k">def</span> <span class="nf">find_bucket</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">key</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-12-22" name="__codelineno-12-22" href="#__codelineno-12-22"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;搜索 key 对应的桶索引&quot;&quot;&quot;</span>
<a id="__codelineno-12-23" name="__codelineno-12-23" href="#__codelineno-12-23"></a> <span class="n">index</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">hash_func</span><span class="p">(</span><span class="n">key</span><span class="p">)</span>
<a id="__codelineno-12-24" name="__codelineno-12-24" href="#__codelineno-12-24"></a> <span class="c1"># 线性探测,从 index 开始向后遍历</span>
<a id="__codelineno-12-25" name="__codelineno-12-25" href="#__codelineno-12-25"></a> <span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">capacity</span><span class="p">):</span>
<a id="__codelineno-12-26" name="__codelineno-12-26" href="#__codelineno-12-26"></a> <span class="c1"># 计算桶索引,越过尾部返回头部</span>
<a id="__codelineno-12-27" name="__codelineno-12-27" href="#__codelineno-12-27"></a> <span class="n">j</span> <span class="o">=</span> <span class="p">(</span><span class="n">index</span> <span class="o">+</span> <span class="n">i</span><span class="p">)</span> <span class="o">%</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span>
<a id="__codelineno-12-28" name="__codelineno-12-28" href="#__codelineno-12-28"></a> <span class="c1"># 若遇到空桶,说明无此 key ,则返回 None</span>
<a id="__codelineno-12-29" name="__codelineno-12-29" href="#__codelineno-12-29"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-12-30" name="__codelineno-12-30" href="#__codelineno-12-30"></a> <span class="k">return</span> <span class="kc">None</span>
<a id="__codelineno-12-31" name="__codelineno-12-31" href="#__codelineno-12-31"></a> <span class="c1"># 若遇到指定 key ,则返回对应 val</span>
<a id="__codelineno-12-32" name="__codelineno-12-32" href="#__codelineno-12-32"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="o">.</span><span class="n">key</span> <span class="o">==</span> <span class="n">key</span> <span class="ow">and</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span> <span class="o">!=</span> <span class="bp">self</span><span class="o">.</span><span class="n">removed</span><span class="p">:</span>
<a id="__codelineno-12-33" name="__codelineno-12-33" href="#__codelineno-12-33"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="o">.</span><span class="n">val</span>
<a id="__codelineno-12-34" name="__codelineno-12-34" href="#__codelineno-12-34"></a>
<a id="__codelineno-12-35" name="__codelineno-12-35" href="#__codelineno-12-35"></a> <span class="k">def</span> <span class="nf">put</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">key</span><span class="p">:</span> <span class="nb">int</span><span class="p">,</span> <span class="n">val</span><span class="p">:</span> <span class="nb">str</span><span class="p">):</span>
<a id="__codelineno-12-36" name="__codelineno-12-36" href="#__codelineno-12-36"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;添加操作&quot;&quot;&quot;</span>
<a id="__codelineno-12-37" name="__codelineno-12-37" href="#__codelineno-12-37"></a> <span class="c1"># 当负载因子超过阈值时,执行扩容</span>
<a id="__codelineno-12-38" name="__codelineno-12-38" href="#__codelineno-12-38"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">load_factor</span><span class="p">()</span> <span class="o">&gt;</span> <span class="bp">self</span><span class="o">.</span><span class="n">load_thres</span><span class="p">:</span>
<a id="__codelineno-12-39" name="__codelineno-12-39" href="#__codelineno-12-39"></a> <span class="bp">self</span><span class="o">.</span><span class="n">extend</span><span class="p">()</span>
<a id="__codelineno-12-40" name="__codelineno-12-40" href="#__codelineno-12-40"></a> <span class="n">index</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">hash_func</span><span class="p">(</span><span class="n">key</span><span class="p">)</span>
<a id="__codelineno-12-41" name="__codelineno-12-41" href="#__codelineno-12-41"></a> <span class="c1"># 线性探测,从 index 开始向后遍历</span>
<a id="__codelineno-12-42" name="__codelineno-12-42" href="#__codelineno-12-42"></a> <span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">capacity</span><span class="p">):</span>
<a id="__codelineno-12-43" name="__codelineno-12-43" href="#__codelineno-12-43"></a> <span class="c1"># 计算桶索引,越过尾部返回头部</span>
<a id="__codelineno-12-44" name="__codelineno-12-44" href="#__codelineno-12-44"></a> <span class="n">j</span> <span class="o">=</span> <span class="p">(</span><span class="n">index</span> <span class="o">+</span> <span class="n">i</span><span class="p">)</span> <span class="o">%</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span>
<a id="__codelineno-12-45" name="__codelineno-12-45" href="#__codelineno-12-45"></a> <span class="c1"># 若遇到空桶、或带有删除标记的桶,则将键值对放入该桶</span>
<a id="__codelineno-12-46" name="__codelineno-12-46" href="#__codelineno-12-46"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span> <span class="ow">in</span> <span class="p">[</span><span class="kc">None</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">removed</span><span class="p">]:</span>
<a id="__codelineno-12-47" name="__codelineno-12-47" href="#__codelineno-12-47"></a> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span> <span class="o">=</span> <span class="n">Pair</span><span class="p">(</span><span class="n">key</span><span class="p">,</span> <span class="n">val</span><span class="p">)</span>
<a id="__codelineno-12-48" name="__codelineno-12-48" href="#__codelineno-12-48"></a> <span class="bp">self</span><span class="o">.</span><span class="n">size</span> <span class="o">+=</span> <span class="mi">1</span>
<a id="__codelineno-12-49" name="__codelineno-12-49" href="#__codelineno-12-49"></a> <span class="k">return</span>
<a id="__codelineno-12-50" name="__codelineno-12-50" href="#__codelineno-12-50"></a> <span class="c1"># 若遇到指定 key ,则更新对应 val</span>
<a id="__codelineno-12-51" name="__codelineno-12-51" href="#__codelineno-12-51"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="o">.</span><span class="n">key</span> <span class="o">==</span> <span class="n">key</span><span class="p">:</span>
<a id="__codelineno-12-52" name="__codelineno-12-52" href="#__codelineno-12-52"></a> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="o">.</span><span class="n">val</span> <span class="o">=</span> <span class="n">val</span>
<a id="__codelineno-12-53" name="__codelineno-12-53" href="#__codelineno-12-53"></a> <span class="k">return</span>
<a id="__codelineno-12-54" name="__codelineno-12-54" href="#__codelineno-12-54"></a>
<a id="__codelineno-12-55" name="__codelineno-12-55" href="#__codelineno-12-55"></a> <span class="k">def</span> <span class="nf">remove</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">key</span><span class="p">:</span> <span class="nb">int</span><span class="p">):</span>
<a id="__codelineno-12-56" name="__codelineno-12-56" href="#__codelineno-12-56"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;删除操作&quot;&quot;&quot;</span>
<a id="__codelineno-12-57" name="__codelineno-12-57" href="#__codelineno-12-57"></a> <span class="n">index</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">hash_func</span><span class="p">(</span><span class="n">key</span><span class="p">)</span>
<a id="__codelineno-12-58" name="__codelineno-12-58" href="#__codelineno-12-58"></a> <span class="c1"># 线性探测,从 index 开始向后遍历</span>
<a id="__codelineno-12-59" name="__codelineno-12-59" href="#__codelineno-12-59"></a> <span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">capacity</span><span class="p">):</span>
<a id="__codelineno-12-60" name="__codelineno-12-60" href="#__codelineno-12-60"></a> <span class="c1"># 计算桶索引,越过尾部返回头部</span>
<a id="__codelineno-12-61" name="__codelineno-12-61" href="#__codelineno-12-61"></a> <span class="n">j</span> <span class="o">=</span> <span class="p">(</span><span class="n">index</span> <span class="o">+</span> <span class="n">i</span><span class="p">)</span> <span class="o">%</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span>
<a id="__codelineno-12-62" name="__codelineno-12-62" href="#__codelineno-12-62"></a> <span class="c1"># 若遇到空桶,说明无此 key ,则直接返回</span>
<a id="__codelineno-12-63" name="__codelineno-12-63" href="#__codelineno-12-63"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-12-64" name="__codelineno-12-64" href="#__codelineno-12-64"></a> <span class="k">return</span>
<a id="__codelineno-12-65" name="__codelineno-12-65" href="#__codelineno-12-65"></a> <span class="c1"># 若遇到指定 key ,则标记删除并返回</span>
<a id="__codelineno-12-66" name="__codelineno-12-66" href="#__codelineno-12-66"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="o">.</span><span class="n">key</span> <span class="o">==</span> <span class="n">key</span><span class="p">:</span>
<a id="__codelineno-12-67" name="__codelineno-12-67" href="#__codelineno-12-67"></a> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">removed</span>
<a id="__codelineno-12-68" name="__codelineno-12-68" href="#__codelineno-12-68"></a> <span class="bp">self</span><span class="o">.</span><span class="n">size</span> <span class="o">-=</span> <span class="mi">1</span>
<a id="__codelineno-12-69" name="__codelineno-12-69" href="#__codelineno-12-69"></a> <span class="k">return</span>
<a id="__codelineno-12-70" name="__codelineno-12-70" href="#__codelineno-12-70"></a>
<a id="__codelineno-12-71" name="__codelineno-12-71" href="#__codelineno-12-71"></a> <span class="k">def</span> <span class="nf">extend</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<a id="__codelineno-12-72" name="__codelineno-12-72" href="#__codelineno-12-72"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;扩容哈希表&quot;&quot;&quot;</span>
<a id="__codelineno-12-73" name="__codelineno-12-73" href="#__codelineno-12-73"></a> <span class="c1"># 暂存原哈希表</span>
<a id="__codelineno-12-74" name="__codelineno-12-74" href="#__codelineno-12-74"></a> <span class="n">buckets_tmp</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span>
<a id="__codelineno-12-75" name="__codelineno-12-75" href="#__codelineno-12-75"></a> <span class="c1"># 初始化扩容后的新哈希表</span>
<a id="__codelineno-12-76" name="__codelineno-12-76" href="#__codelineno-12-76"></a> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span> <span class="o">*=</span> <span class="bp">self</span><span class="o">.</span><span class="n">extend_ratio</span>
<a id="__codelineno-12-77" name="__codelineno-12-77" href="#__codelineno-12-77"></a> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span> <span class="o">=</span> <span class="p">[</span><span class="kc">None</span><span class="p">]</span> <span class="o">*</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span>
<a id="__codelineno-12-78" name="__codelineno-12-78" href="#__codelineno-12-78"></a> <span class="bp">self</span><span class="o">.</span><span class="n">size</span> <span class="o">=</span> <span class="mi">0</span>
<a id="__codelineno-12-79" name="__codelineno-12-79" href="#__codelineno-12-79"></a> <span class="c1"># 将键值对从原哈希表搬运至新哈希表</span>
<a id="__codelineno-12-80" name="__codelineno-12-80" href="#__codelineno-12-80"></a> <span class="k">for</span> <span class="n">pair</span> <span class="ow">in</span> <span class="n">buckets_tmp</span><span class="p">:</span>
<a id="__codelineno-12-81" name="__codelineno-12-81" href="#__codelineno-12-81"></a> <span class="k">if</span> <span class="n">pair</span> <span class="ow">not</span> <span class="ow">in</span> <span class="p">[</span><span class="kc">None</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">removed</span><span class="p">]:</span>
<a id="__codelineno-12-82" name="__codelineno-12-82" href="#__codelineno-12-82"></a> <span class="bp">self</span><span class="o">.</span><span class="n">put</span><span class="p">(</span><span class="n">pair</span><span class="o">.</span><span class="n">key</span><span class="p">,</span> <span class="n">pair</span><span class="o">.</span><span class="n">val</span><span class="p">)</span>
<a id="__codelineno-12-83" name="__codelineno-12-83" href="#__codelineno-12-83"></a>
<a id="__codelineno-12-84" name="__codelineno-12-84" href="#__codelineno-12-84"></a> <span class="k">def</span> <span class="nf">print</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<a id="__codelineno-12-85" name="__codelineno-12-85" href="#__codelineno-12-85"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;打印哈希表&quot;&quot;&quot;</span>
<a id="__codelineno-12-86" name="__codelineno-12-86" href="#__codelineno-12-86"></a> <span class="k">for</span> <span class="n">pair</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">:</span>
<a id="__codelineno-12-87" name="__codelineno-12-87" href="#__codelineno-12-87"></a> <span class="k">if</span> <span class="n">pair</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-12-88" name="__codelineno-12-88" href="#__codelineno-12-88"></a> <span class="nb">print</span><span class="p">(</span><span class="n">pair</span><span class="o">.</span><span class="n">key</span><span class="p">,</span> <span class="s2">&quot;-&gt;&quot;</span><span class="p">,</span> <span class="n">pair</span><span class="o">.</span><span class="n">val</span><span class="p">)</span>
<a id="__codelineno-12-89" name="__codelineno-12-89" href="#__codelineno-12-89"></a> <span class="k">else</span><span class="p">:</span>
<a id="__codelineno-12-90" name="__codelineno-12-90" href="#__codelineno-12-90"></a> <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;None&quot;</span><span class="p">)</span>
<a id="__codelineno-12-24" name="__codelineno-12-24" href="#__codelineno-12-24"></a> <span class="n">first_tombstone</span> <span class="o">=</span> <span class="o">-</span><span class="mi">1</span>
<a id="__codelineno-12-25" name="__codelineno-12-25" href="#__codelineno-12-25"></a> <span class="c1"># 线性探测,当遇到空桶时跳出</span>
<a id="__codelineno-12-26" name="__codelineno-12-26" href="#__codelineno-12-26"></a> <span class="k">while</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-12-27" name="__codelineno-12-27" href="#__codelineno-12-27"></a> <span class="c1"># 若遇到 key ,返回对应桶索引</span>
<a id="__codelineno-12-28" name="__codelineno-12-28" href="#__codelineno-12-28"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="o">.</span><span class="n">key</span> <span class="o">==</span> <span class="n">key</span><span class="p">:</span>
<a id="__codelineno-12-29" name="__codelineno-12-29" href="#__codelineno-12-29"></a> <span class="c1"># 若之前遇到了删除标记,则将键值对移动至该索引</span>
<a id="__codelineno-12-30" name="__codelineno-12-30" href="#__codelineno-12-30"></a> <span class="k">if</span> <span class="n">first_tombstone</span> <span class="o">!=</span> <span class="o">-</span><span class="mi">1</span><span class="p">:</span>
<a id="__codelineno-12-31" name="__codelineno-12-31" href="#__codelineno-12-31"></a> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">first_tombstone</span><span class="p">]</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span>
<a id="__codelineno-12-32" name="__codelineno-12-32" href="#__codelineno-12-32"></a> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">TOMBSTONE</span>
<a id="__codelineno-12-33" name="__codelineno-12-33" href="#__codelineno-12-33"></a> <span class="k">return</span> <span class="n">first_tombstone</span> <span class="c1"># 返回移动后的桶索引</span>
<a id="__codelineno-12-34" name="__codelineno-12-34" href="#__codelineno-12-34"></a> <span class="k">return</span> <span class="n">index</span> <span class="c1"># 返回桶索引</span>
<a id="__codelineno-12-35" name="__codelineno-12-35" href="#__codelineno-12-35"></a> <span class="c1"># 记录遇到的首个删除标记</span>
<a id="__codelineno-12-36" name="__codelineno-12-36" href="#__codelineno-12-36"></a> <span class="k">if</span> <span class="n">first_tombstone</span> <span class="o">==</span> <span class="o">-</span><span class="mi">1</span> <span class="ow">and</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span> <span class="ow">is</span> <span class="bp">self</span><span class="o">.</span><span class="n">TOMBSTONE</span><span class="p">:</span>
<a id="__codelineno-12-37" name="__codelineno-12-37" href="#__codelineno-12-37"></a> <span class="n">first_tombstone</span> <span class="o">=</span> <span class="n">index</span>
<a id="__codelineno-12-38" name="__codelineno-12-38" href="#__codelineno-12-38"></a> <span class="c1"># 计算桶索引,越过尾部返回头部</span>
<a id="__codelineno-12-39" name="__codelineno-12-39" href="#__codelineno-12-39"></a> <span class="n">index</span> <span class="o">=</span> <span class="p">(</span><span class="n">index</span> <span class="o">+</span> <span class="mi">1</span><span class="p">)</span> <span class="o">%</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span>
<a id="__codelineno-12-40" name="__codelineno-12-40" href="#__codelineno-12-40"></a> <span class="c1"># 若 key 不存在,则返回添加点的索引</span>
<a id="__codelineno-12-41" name="__codelineno-12-41" href="#__codelineno-12-41"></a> <span class="k">return</span> <span class="n">index</span> <span class="k">if</span> <span class="n">first_tombstone</span> <span class="o">==</span> <span class="o">-</span><span class="mi">1</span> <span class="k">else</span> <span class="n">first_tombstone</span>
<a id="__codelineno-12-42" name="__codelineno-12-42" href="#__codelineno-12-42"></a>
<a id="__codelineno-12-43" name="__codelineno-12-43" href="#__codelineno-12-43"></a> <span class="k">def</span> <span class="nf">get</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">key</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">str</span><span class="p">:</span>
<a id="__codelineno-12-44" name="__codelineno-12-44" href="#__codelineno-12-44"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;查询操作&quot;&quot;&quot;</span>
<a id="__codelineno-12-45" name="__codelineno-12-45" href="#__codelineno-12-45"></a> <span class="c1"># 搜索 key 对应的桶索引</span>
<a id="__codelineno-12-46" name="__codelineno-12-46" href="#__codelineno-12-46"></a> <span class="n">index</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">find_bucket</span><span class="p">(</span><span class="n">key</span><span class="p">)</span>
<a id="__codelineno-12-47" name="__codelineno-12-47" href="#__codelineno-12-47"></a> <span class="c1"># 若找到键值对,则返回对应 val</span>
<a id="__codelineno-12-48" name="__codelineno-12-48" href="#__codelineno-12-48"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span> <span class="ow">not</span> <span class="ow">in</span> <span class="p">[</span><span class="kc">None</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">TOMBSTONE</span><span class="p">]:</span>
<a id="__codelineno-12-49" name="__codelineno-12-49" href="#__codelineno-12-49"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="o">.</span><span class="n">val</span>
<a id="__codelineno-12-50" name="__codelineno-12-50" href="#__codelineno-12-50"></a> <span class="c1"># 若键值对不存在,则返回 None</span>
<a id="__codelineno-12-51" name="__codelineno-12-51" href="#__codelineno-12-51"></a> <span class="k">return</span> <span class="kc">None</span>
<a id="__codelineno-12-52" name="__codelineno-12-52" href="#__codelineno-12-52"></a>
<a id="__codelineno-12-53" name="__codelineno-12-53" href="#__codelineno-12-53"></a> <span class="k">def</span> <span class="nf">put</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">key</span><span class="p">:</span> <span class="nb">int</span><span class="p">,</span> <span class="n">val</span><span class="p">:</span> <span class="nb">str</span><span class="p">):</span>
<a id="__codelineno-12-54" name="__codelineno-12-54" href="#__codelineno-12-54"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;添加操作&quot;&quot;&quot;</span>
<a id="__codelineno-12-55" name="__codelineno-12-55" href="#__codelineno-12-55"></a> <span class="c1"># 当负载因子超过阈值时,执行扩容</span>
<a id="__codelineno-12-56" name="__codelineno-12-56" href="#__codelineno-12-56"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">load_factor</span><span class="p">()</span> <span class="o">&gt;</span> <span class="bp">self</span><span class="o">.</span><span class="n">load_thres</span><span class="p">:</span>
<a id="__codelineno-12-57" name="__codelineno-12-57" href="#__codelineno-12-57"></a> <span class="bp">self</span><span class="o">.</span><span class="n">extend</span><span class="p">()</span>
<a id="__codelineno-12-58" name="__codelineno-12-58" href="#__codelineno-12-58"></a> <span class="c1"># 搜索 key 对应的桶索引</span>
<a id="__codelineno-12-59" name="__codelineno-12-59" href="#__codelineno-12-59"></a> <span class="n">index</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">find_bucket</span><span class="p">(</span><span class="n">key</span><span class="p">)</span>
<a id="__codelineno-12-60" name="__codelineno-12-60" href="#__codelineno-12-60"></a> <span class="c1"># 若找到键值对,则覆盖 val 并返回</span>
<a id="__codelineno-12-61" name="__codelineno-12-61" href="#__codelineno-12-61"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span> <span class="ow">not</span> <span class="ow">in</span> <span class="p">[</span><span class="kc">None</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">TOMBSTONE</span><span class="p">]:</span>
<a id="__codelineno-12-62" name="__codelineno-12-62" href="#__codelineno-12-62"></a> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="o">.</span><span class="n">val</span> <span class="o">=</span> <span class="n">val</span>
<a id="__codelineno-12-63" name="__codelineno-12-63" href="#__codelineno-12-63"></a> <span class="k">return</span>
<a id="__codelineno-12-64" name="__codelineno-12-64" href="#__codelineno-12-64"></a> <span class="c1"># 若键值对不存在,则添加该键值对</span>
<a id="__codelineno-12-65" name="__codelineno-12-65" href="#__codelineno-12-65"></a> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span> <span class="o">=</span> <span class="n">Pair</span><span class="p">(</span><span class="n">key</span><span class="p">,</span> <span class="n">val</span><span class="p">)</span>
<a id="__codelineno-12-66" name="__codelineno-12-66" href="#__codelineno-12-66"></a> <span class="bp">self</span><span class="o">.</span><span class="n">size</span> <span class="o">+=</span> <span class="mi">1</span>
<a id="__codelineno-12-67" name="__codelineno-12-67" href="#__codelineno-12-67"></a>
<a id="__codelineno-12-68" name="__codelineno-12-68" href="#__codelineno-12-68"></a> <span class="k">def</span> <span class="nf">remove</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">key</span><span class="p">:</span> <span class="nb">int</span><span class="p">):</span>
<a id="__codelineno-12-69" name="__codelineno-12-69" href="#__codelineno-12-69"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;删除操作&quot;&quot;&quot;</span>
<a id="__codelineno-12-70" name="__codelineno-12-70" href="#__codelineno-12-70"></a> <span class="c1"># 搜索 key 对应的桶索引</span>
<a id="__codelineno-12-71" name="__codelineno-12-71" href="#__codelineno-12-71"></a> <span class="n">index</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">find_bucket</span><span class="p">(</span><span class="n">key</span><span class="p">)</span>
<a id="__codelineno-12-72" name="__codelineno-12-72" href="#__codelineno-12-72"></a> <span class="c1"># 若找到键值对,则用删除标记覆盖它</span>
<a id="__codelineno-12-73" name="__codelineno-12-73" href="#__codelineno-12-73"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span> <span class="ow">not</span> <span class="ow">in</span> <span class="p">[</span><span class="kc">None</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">TOMBSTONE</span><span class="p">]:</span>
<a id="__codelineno-12-74" name="__codelineno-12-74" href="#__codelineno-12-74"></a> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">TOMBSTONE</span>
<a id="__codelineno-12-75" name="__codelineno-12-75" href="#__codelineno-12-75"></a> <span class="bp">self</span><span class="o">.</span><span class="n">size</span> <span class="o">-=</span> <span class="mi">1</span>
<a id="__codelineno-12-76" name="__codelineno-12-76" href="#__codelineno-12-76"></a>
<a id="__codelineno-12-77" name="__codelineno-12-77" href="#__codelineno-12-77"></a> <span class="k">def</span> <span class="nf">extend</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<a id="__codelineno-12-78" name="__codelineno-12-78" href="#__codelineno-12-78"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;扩容哈希表&quot;&quot;&quot;</span>
<a id="__codelineno-12-79" name="__codelineno-12-79" href="#__codelineno-12-79"></a> <span class="c1"># 暂存原哈希表</span>
<a id="__codelineno-12-80" name="__codelineno-12-80" href="#__codelineno-12-80"></a> <span class="n">buckets_tmp</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span>
<a id="__codelineno-12-81" name="__codelineno-12-81" href="#__codelineno-12-81"></a> <span class="c1"># 初始化扩容后的新哈希表</span>
<a id="__codelineno-12-82" name="__codelineno-12-82" href="#__codelineno-12-82"></a> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span> <span class="o">*=</span> <span class="bp">self</span><span class="o">.</span><span class="n">extend_ratio</span>
<a id="__codelineno-12-83" name="__codelineno-12-83" href="#__codelineno-12-83"></a> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span> <span class="o">=</span> <span class="p">[</span><span class="kc">None</span><span class="p">]</span> <span class="o">*</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span>
<a id="__codelineno-12-84" name="__codelineno-12-84" href="#__codelineno-12-84"></a> <span class="bp">self</span><span class="o">.</span><span class="n">size</span> <span class="o">=</span> <span class="mi">0</span>
<a id="__codelineno-12-85" name="__codelineno-12-85" href="#__codelineno-12-85"></a> <span class="c1"># 将键值对从原哈希表搬运至新哈希表</span>
<a id="__codelineno-12-86" name="__codelineno-12-86" href="#__codelineno-12-86"></a> <span class="k">for</span> <span class="n">pair</span> <span class="ow">in</span> <span class="n">buckets_tmp</span><span class="p">:</span>
<a id="__codelineno-12-87" name="__codelineno-12-87" href="#__codelineno-12-87"></a> <span class="k">if</span> <span class="n">pair</span> <span class="ow">not</span> <span class="ow">in</span> <span class="p">[</span><span class="kc">None</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">TOMBSTONE</span><span class="p">]:</span>
<a id="__codelineno-12-88" name="__codelineno-12-88" href="#__codelineno-12-88"></a> <span class="bp">self</span><span class="o">.</span><span class="n">put</span><span class="p">(</span><span class="n">pair</span><span class="o">.</span><span class="n">key</span><span class="p">,</span> <span class="n">pair</span><span class="o">.</span><span class="n">val</span><span class="p">)</span>
<a id="__codelineno-12-89" name="__codelineno-12-89" href="#__codelineno-12-89"></a>
<a id="__codelineno-12-90" name="__codelineno-12-90" href="#__codelineno-12-90"></a> <span class="k">def</span> <span class="nf">print</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<a id="__codelineno-12-91" name="__codelineno-12-91" href="#__codelineno-12-91"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;打印哈希表&quot;&quot;&quot;</span>
<a id="__codelineno-12-92" name="__codelineno-12-92" href="#__codelineno-12-92"></a> <span class="k">for</span> <span class="n">pair</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">buckets</span><span class="p">:</span>
<a id="__codelineno-12-93" name="__codelineno-12-93" href="#__codelineno-12-93"></a> <span class="k">if</span> <span class="n">pair</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-12-94" name="__codelineno-12-94" href="#__codelineno-12-94"></a> <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;None&quot;</span><span class="p">)</span>
<a id="__codelineno-12-95" name="__codelineno-12-95" href="#__codelineno-12-95"></a> <span class="k">elif</span> <span class="n">pair</span> <span class="ow">is</span> <span class="bp">self</span><span class="o">.</span><span class="n">TOMBSTONE</span><span class="p">:</span>
<a id="__codelineno-12-96" name="__codelineno-12-96" href="#__codelineno-12-96"></a> <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;TOMBSTONE&quot;</span><span class="p">)</span>
<a id="__codelineno-12-97" name="__codelineno-12-97" href="#__codelineno-12-97"></a> <span class="k">else</span><span class="p">:</span>
<a id="__codelineno-12-98" name="__codelineno-12-98" href="#__codelineno-12-98"></a> <span class="nb">print</span><span class="p">(</span><span class="n">pair</span><span class="o">.</span><span class="n">key</span><span class="p">,</span> <span class="s2">&quot;-&gt;&quot;</span><span class="p">,</span> <span class="n">pair</span><span class="o">.</span><span class="n">val</span><span class="p">)</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">hash_map_open_addressing.cpp</span><pre><span></span><code><a id="__codelineno-13-1" name="__codelineno-13-1" href="#__codelineno-13-1"></a><span class="cm">/* 开放寻址哈希表 */</span>
<a id="__codelineno-13-2" name="__codelineno-13-2" href="#__codelineno-13-2"></a><span class="k">class</span><span class="w"> </span><span class="nc">HashMapOpenAddressing</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="k">private</span><span class="o">:</span>
<a id="__codelineno-13-4" name="__codelineno-13-4" href="#__codelineno-13-4"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="p">;</span><span class="w"> </span><span class="c1">// 键值对数量</span>
<a id="__codelineno-13-5" name="__codelineno-13-5" href="#__codelineno-13-5"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span><span class="w"> </span><span class="c1">// 哈希表容量</span>
<a id="__codelineno-13-6" name="__codelineno-13-6" href="#__codelineno-13-6"></a><span class="w"> </span><span class="kt">double</span><span class="w"> </span><span class="n">loadThres</span><span class="p">;</span><span class="w"> </span><span class="c1">// 触发扩容的负载因子阈值</span>
<a id="__codelineno-13-7" name="__codelineno-13-7" href="#__codelineno-13-7"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">extendRatio</span><span class="p">;</span><span class="w"> </span><span class="c1">// 扩容倍数</span>
<a id="__codelineno-13-8" name="__codelineno-13-8" href="#__codelineno-13-8"></a><span class="w"> </span><span class="n">vector</span><span class="o">&lt;</span><span class="n">Pair</span><span class="w"> </span><span class="o">*&gt;</span><span class="w"> </span><span class="n">buckets</span><span class="p">;</span><span class="w"> </span><span class="c1">// 桶数组</span>
<a id="__codelineno-13-9" name="__codelineno-13-9" href="#__codelineno-13-9"></a><span class="w"> </span><span class="n">Pair</span><span class="w"> </span><span class="o">*</span><span class="n">removed</span><span class="p">;</span><span class="w"> </span><span class="c1">// 删除标记</span>
<a id="__codelineno-13-10" name="__codelineno-13-10" href="#__codelineno-13-10"></a>
<a id="__codelineno-13-11" name="__codelineno-13-11" href="#__codelineno-13-11"></a><span class="w"> </span><span class="k">public</span><span class="o">:</span>
<a id="__codelineno-13-12" name="__codelineno-13-12" href="#__codelineno-13-12"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-13-13" name="__codelineno-13-13" href="#__codelineno-13-13"></a><span class="w"> </span><span class="n">HashMapOpenAddressing</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="c1">// 构造方法</span>
<a id="__codelineno-13-15" name="__codelineno-13-15" href="#__codelineno-13-15"></a><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-13-16" name="__codelineno-13-16" href="#__codelineno-13-16"></a><span class="w"> </span><span class="n">capacity</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">4</span><span class="p">;</span>
<a id="__codelineno-13-17" name="__codelineno-13-17" href="#__codelineno-13-17"></a><span class="w"> </span><span class="n">loadThres</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">2.0</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">3.0</span><span class="p">;</span>
<a id="__codelineno-13-18" name="__codelineno-13-18" href="#__codelineno-13-18"></a><span class="w"> </span><span class="n">extendRatio</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">2</span><span class="p">;</span>
<a id="__codelineno-13-19" name="__codelineno-13-19" href="#__codelineno-13-19"></a><span class="w"> </span><span class="n">buckets</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">vector</span><span class="o">&lt;</span><span class="n">Pair</span><span class="w"> </span><span class="o">*&gt;</span><span class="p">(</span><span class="n">capacity</span><span class="p">,</span><span class="w"> </span><span class="k">nullptr</span><span class="p">);</span>
<a id="__codelineno-13-20" name="__codelineno-13-20" href="#__codelineno-13-20"></a><span class="w"> </span><span class="n">removed</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">Pair</span><span class="p">(</span><span class="mi">-1</span><span class="p">,</span><span class="w"> </span><span class="s">&quot;-1&quot;</span><span class="p">);</span>
<div class="highlight"><span class="filename">hash_map_open_addressing.cpp</span><pre><span></span><code><a id="__codelineno-13-1" name="__codelineno-13-1" href="#__codelineno-13-1"></a><span class="cm">/**</span>
<a id="__codelineno-13-2" name="__codelineno-13-2" href="#__codelineno-13-2"></a><span class="cm"> * File: hash_map_open_addressing.cpp</span>
<a id="__codelineno-13-3" name="__codelineno-13-3" href="#__codelineno-13-3"></a><span class="cm"> * Created Time: 2023-06-13</span>
<a id="__codelineno-13-4" name="__codelineno-13-4" href="#__codelineno-13-4"></a><span class="cm"> * Author: Krahets (krahets@163.com)</span>
<a id="__codelineno-13-5" name="__codelineno-13-5" href="#__codelineno-13-5"></a><span class="cm"> */</span>
<a id="__codelineno-13-6" name="__codelineno-13-6" href="#__codelineno-13-6"></a>
<a id="__codelineno-13-7" name="__codelineno-13-7" href="#__codelineno-13-7"></a><span class="cp">#include</span><span class="w"> </span><span class="cpf">&quot;./array_hash_map.cpp&quot;</span>
<a id="__codelineno-13-8" name="__codelineno-13-8" href="#__codelineno-13-8"></a>
<a id="__codelineno-13-9" name="__codelineno-13-9" href="#__codelineno-13-9"></a><span class="k">class</span><span class="w"> </span><span class="nc">HashMapOpenAddressing</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-10" name="__codelineno-13-10" href="#__codelineno-13-10"></a><span class="w"> </span><span class="k">private</span><span class="o">:</span>
<a id="__codelineno-13-11" name="__codelineno-13-11" href="#__codelineno-13-11"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="p">;</span><span class="w"> </span><span class="c1">// 键值对数量</span>
<a id="__codelineno-13-12" name="__codelineno-13-12" href="#__codelineno-13-12"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">4</span><span class="p">;</span><span class="w"> </span><span class="c1">// 哈希表容量</span>
<a id="__codelineno-13-13" name="__codelineno-13-13" href="#__codelineno-13-13"></a><span class="w"> </span><span class="k">const</span><span class="w"> </span><span class="kt">double</span><span class="w"> </span><span class="n">loadThres</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">2.0</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mi">3</span><span class="p">;</span><span class="w"> </span><span class="c1">// 触发扩容的负载因子阈值</span>
<a id="__codelineno-13-14" name="__codelineno-13-14" href="#__codelineno-13-14"></a><span class="w"> </span><span class="k">const</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">extendRatio</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">2</span><span class="p">;</span><span class="w"> </span><span class="c1">// 扩容倍数</span>
<a id="__codelineno-13-15" name="__codelineno-13-15" href="#__codelineno-13-15"></a><span class="w"> </span><span class="n">vector</span><span class="o">&lt;</span><span class="n">Pair</span><span class="w"> </span><span class="o">*&gt;</span><span class="w"> </span><span class="n">buckets</span><span class="p">;</span><span class="w"> </span><span class="c1">// 桶数组</span>
<a id="__codelineno-13-16" name="__codelineno-13-16" href="#__codelineno-13-16"></a><span class="w"> </span><span class="n">Pair</span><span class="w"> </span><span class="o">*</span><span class="n">TOMBSTONE</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">Pair</span><span class="p">(</span><span class="mi">-1</span><span class="p">,</span><span class="w"> </span><span class="s">&quot;-1&quot;</span><span class="p">);</span><span class="w"> </span><span class="c1">// 删除标记</span>
<a id="__codelineno-13-17" name="__codelineno-13-17" href="#__codelineno-13-17"></a>
<a id="__codelineno-13-18" name="__codelineno-13-18" href="#__codelineno-13-18"></a><span class="w"> </span><span class="k">public</span><span class="o">:</span>
<a id="__codelineno-13-19" name="__codelineno-13-19" href="#__codelineno-13-19"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-13-20" name="__codelineno-13-20" href="#__codelineno-13-20"></a><span class="w"> </span><span class="n">HashMapOpenAddressing</span><span class="p">()</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">size</span><span class="p">(</span><span class="mi">0</span><span class="p">),</span><span class="w"> </span><span class="n">buckets</span><span class="p">(</span><span class="n">capacity</span><span class="p">,</span><span class="w"> </span><span class="k">nullptr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-21" name="__codelineno-13-21" href="#__codelineno-13-21"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-22" name="__codelineno-13-22" href="#__codelineno-13-22"></a>
<a id="__codelineno-13-23" name="__codelineno-13-23" href="#__codelineno-13-23"></a><span class="w"> </span><span class="cm">/* 哈希函数 */</span>
<a id="__codelineno-13-24" name="__codelineno-13-24" href="#__codelineno-13-24"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">hashFunc</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-25" name="__codelineno-13-25" href="#__codelineno-13-25"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">key</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-13-26" name="__codelineno-13-26" href="#__codelineno-13-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-27" name="__codelineno-13-27" href="#__codelineno-13-27"></a>
<a id="__codelineno-13-28" name="__codelineno-13-28" href="#__codelineno-13-28"></a><span class="w"> </span><span class="cm">/* 负载因子 */</span>
<a id="__codelineno-13-29" name="__codelineno-13-29" href="#__codelineno-13-29"></a><span class="w"> </span><span class="kt">double</span><span class="w"> </span><span class="n">loadFactor</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-30" name="__codelineno-13-30" href="#__codelineno-13-30"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">static_cast</span><span class="o">&lt;</span><span class="kt">double</span><span class="o">&gt;</span><span class="p">(</span><span class="n">size</span><span class="p">)</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-13-23" name="__codelineno-13-23" href="#__codelineno-13-23"></a><span class="w"> </span><span class="cm">/* 析构方法 */</span>
<a id="__codelineno-13-24" name="__codelineno-13-24" href="#__codelineno-13-24"></a><span class="w"> </span><span class="o">~</span><span class="n">HashMapOpenAddressing</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-25" name="__codelineno-13-25" href="#__codelineno-13-25"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="n">Pair</span><span class="w"> </span><span class="o">*</span><span class="n">pair</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">buckets</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-26" name="__codelineno-13-26" href="#__codelineno-13-26"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">pair</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">nullptr</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">pair</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-27" name="__codelineno-13-27" href="#__codelineno-13-27"></a><span class="w"> </span><span class="k">delete</span><span class="w"> </span><span class="n">pair</span><span class="p">;</span>
<a id="__codelineno-13-28" name="__codelineno-13-28" href="#__codelineno-13-28"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-29" name="__codelineno-13-29" href="#__codelineno-13-29"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-30" name="__codelineno-13-30" href="#__codelineno-13-30"></a><span class="w"> </span><span class="k">delete</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">;</span>
<a id="__codelineno-13-31" name="__codelineno-13-31" href="#__codelineno-13-31"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-32" name="__codelineno-13-32" href="#__codelineno-13-32"></a>
<a id="__codelineno-13-33" name="__codelineno-13-33" href="#__codelineno-13-33"></a><span class="w"> </span><span class="cm">/* 查询操作 */</span>
<a id="__codelineno-13-34" name="__codelineno-13-34" href="#__codelineno-13-34"></a><span class="w"> </span><span class="n">string</span><span class="w"> </span><span class="n">get</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-35" name="__codelineno-13-35" href="#__codelineno-13-35"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">hashFunc</span><span class="p">(</span><span class="n">key</span><span class="p">);</span>
<a id="__codelineno-13-36" name="__codelineno-13-36" href="#__codelineno-13-36"></a><span class="w"> </span><span class="c1">// 线性探测,从 index 开始向后遍历</span>
<a id="__codelineno-13-37" name="__codelineno-13-37" href="#__codelineno-13-37"></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">capacity</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-13-38" name="__codelineno-13-38" href="#__codelineno-13-38"></a><span class="w"> </span><span class="c1">// 计算桶索引,越过尾部返回头部</span>
<a id="__codelineno-13-39" name="__codelineno-13-39" href="#__codelineno-13-39"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="n">index</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="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-13-40" name="__codelineno-13-40" href="#__codelineno-13-40"></a><span class="w"> </span><span class="c1">// 若遇到空桶,说明无此 key ,则返回 nullptr</span>
<a id="__codelineno-13-41" name="__codelineno-13-41" href="#__codelineno-13-41"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="k">nullptr</span><span class="p">)</span>
<a id="__codelineno-13-42" name="__codelineno-13-42" href="#__codelineno-13-42"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">nullptr</span><span class="p">;</span>
<a id="__codelineno-13-43" name="__codelineno-13-43" href="#__codelineno-13-43"></a><span class="w"> </span><span class="c1">// 若遇到指定 key ,则返回对应 val</span>
<a id="__codelineno-13-44" name="__codelineno-13-44" href="#__codelineno-13-44"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="o">-&gt;</span><span class="n">key</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">key</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="n">removed</span><span class="p">)</span>
<a id="__codelineno-13-45" name="__codelineno-13-45" href="#__codelineno-13-45"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-13-46" name="__codelineno-13-46" href="#__codelineno-13-46"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-47" name="__codelineno-13-47" href="#__codelineno-13-47"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">nullptr</span><span class="p">;</span>
<a id="__codelineno-13-48" name="__codelineno-13-48" href="#__codelineno-13-48"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-49" name="__codelineno-13-49" href="#__codelineno-13-49"></a>
<a id="__codelineno-13-50" name="__codelineno-13-50" href="#__codelineno-13-50"></a><span class="w"> </span><span class="cm">/* 添加操作 */</span>
<a id="__codelineno-13-51" name="__codelineno-13-51" href="#__codelineno-13-51"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">put</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">,</span><span class="w"> </span><span class="n">string</span><span class="w"> </span><span class="n">val</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-52" name="__codelineno-13-52" href="#__codelineno-13-52"></a><span class="w"> </span><span class="c1">// 当负载因子超过阈值时,执行扩容</span>
<a id="__codelineno-13-53" name="__codelineno-13-53" href="#__codelineno-13-53"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">loadFactor</span><span class="p">()</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">loadThres</span><span class="p">)</span>
<a id="__codelineno-13-54" name="__codelineno-13-54" href="#__codelineno-13-54"></a><span class="w"> </span><span class="n">extend</span><span class="p">();</span>
<a id="__codelineno-13-55" name="__codelineno-13-55" href="#__codelineno-13-55"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">hashFunc</span><span class="p">(</span><span class="n">key</span><span class="p">);</span>
<a id="__codelineno-13-56" name="__codelineno-13-56" href="#__codelineno-13-56"></a><span class="w"> </span><span class="c1">// 线性探测,从 index 开始向后遍历</span>
<a id="__codelineno-13-57" name="__codelineno-13-57" href="#__codelineno-13-57"></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">capacity</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-13-58" name="__codelineno-13-58" href="#__codelineno-13-58"></a><span class="w"> </span><span class="c1">// 计算桶索引,越过尾部返回头部</span>
<a id="__codelineno-13-59" name="__codelineno-13-59" href="#__codelineno-13-59"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="n">index</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="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-13-60" name="__codelineno-13-60" href="#__codelineno-13-60"></a><span class="w"> </span><span class="c1">// 若遇到空桶、或带有删除标记的桶,则将键值对放入该桶</span>
<a id="__codelineno-13-61" name="__codelineno-13-61" href="#__codelineno-13-61"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="k">nullptr</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">removed</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-62" name="__codelineno-13-62" href="#__codelineno-13-62"></a><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">Pair</span><span class="p">(</span><span class="n">key</span><span class="p">,</span><span class="w"> </span><span class="n">val</span><span class="p">);</span>
<a id="__codelineno-13-63" name="__codelineno-13-63" href="#__codelineno-13-63"></a><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">+=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
<a id="__codelineno-13-64" name="__codelineno-13-64" href="#__codelineno-13-64"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-13-65" name="__codelineno-13-65" href="#__codelineno-13-65"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-66" name="__codelineno-13-66" href="#__codelineno-13-66"></a><span class="w"> </span><span class="c1">// 若遇到指定 key ,则更新对应 val</span>
<a id="__codelineno-13-67" name="__codelineno-13-67" href="#__codelineno-13-67"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="o">-&gt;</span><span class="n">key</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-68" name="__codelineno-13-68" href="#__codelineno-13-68"></a><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="o">-&gt;</span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-13-69" name="__codelineno-13-69" href="#__codelineno-13-69"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-13-70" name="__codelineno-13-70" href="#__codelineno-13-70"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-71" name="__codelineno-13-71" href="#__codelineno-13-71"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-72" name="__codelineno-13-72" href="#__codelineno-13-72"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-73" name="__codelineno-13-73" href="#__codelineno-13-73"></a>
<a id="__codelineno-13-74" name="__codelineno-13-74" href="#__codelineno-13-74"></a><span class="w"> </span><span class="cm">/* 删除操作 */</span>
<a id="__codelineno-13-75" name="__codelineno-13-75" href="#__codelineno-13-75"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">remove</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-76" name="__codelineno-13-76" href="#__codelineno-13-76"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">hashFunc</span><span class="p">(</span><span class="n">key</span><span class="p">);</span>
<a id="__codelineno-13-77" name="__codelineno-13-77" href="#__codelineno-13-77"></a><span class="w"> </span><span class="c1">// 线性探测,从 index 开始向后遍历</span>
<a id="__codelineno-13-78" name="__codelineno-13-78" href="#__codelineno-13-78"></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">capacity</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-13-79" name="__codelineno-13-79" href="#__codelineno-13-79"></a><span class="w"> </span><span class="c1">// 计算桶索引,越过尾部返回头部</span>
<a id="__codelineno-13-80" name="__codelineno-13-80" href="#__codelineno-13-80"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="n">index</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="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-13-81" name="__codelineno-13-81" href="#__codelineno-13-81"></a><span class="w"> </span><span class="c1">// 若遇到空桶,说明无此 key ,则直接返回</span>
<a id="__codelineno-13-82" name="__codelineno-13-82" href="#__codelineno-13-82"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="k">nullptr</span><span class="p">)</span>
<a id="__codelineno-13-83" name="__codelineno-13-83" href="#__codelineno-13-83"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-13-84" name="__codelineno-13-84" href="#__codelineno-13-84"></a><span class="w"> </span><span class="c1">// 若遇到指定 key ,则标记删除并返回</span>
<a id="__codelineno-13-85" name="__codelineno-13-85" href="#__codelineno-13-85"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="o">-&gt;</span><span class="n">key</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-86" name="__codelineno-13-86" href="#__codelineno-13-86"></a><span class="w"> </span><span class="k">delete</span><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">];</span><span class="w"> </span><span class="c1">// 释放内存</span>
<a id="__codelineno-13-87" name="__codelineno-13-87" href="#__codelineno-13-87"></a><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">j</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">removed</span><span class="p">;</span>
<a id="__codelineno-13-88" name="__codelineno-13-88" href="#__codelineno-13-88"></a><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">-=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
<a id="__codelineno-13-89" name="__codelineno-13-89" href="#__codelineno-13-89"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-13-90" name="__codelineno-13-90" href="#__codelineno-13-90"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-91" name="__codelineno-13-91" href="#__codelineno-13-91"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-92" name="__codelineno-13-92" href="#__codelineno-13-92"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-93" name="__codelineno-13-93" href="#__codelineno-13-93"></a>
<a id="__codelineno-13-94" name="__codelineno-13-94" href="#__codelineno-13-94"></a><span class="w"> </span><span class="cm">/* 扩容哈希表 */</span>
<a id="__codelineno-13-95" name="__codelineno-13-95" href="#__codelineno-13-95"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">extend</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-96" name="__codelineno-13-96" href="#__codelineno-13-96"></a><span class="w"> </span><span class="c1">// 暂存原哈希表</span>
<a id="__codelineno-13-97" name="__codelineno-13-97" href="#__codelineno-13-97"></a><span class="w"> </span><span class="n">vector</span><span class="o">&lt;</span><span class="n">Pair</span><span class="w"> </span><span class="o">*&gt;</span><span class="w"> </span><span class="n">bucketsTmp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">buckets</span><span class="p">;</span>
<a id="__codelineno-13-98" name="__codelineno-13-98" href="#__codelineno-13-98"></a><span class="w"> </span><span class="c1">// 初始化扩容后的新哈希表</span>
<a id="__codelineno-13-99" name="__codelineno-13-99" href="#__codelineno-13-99"></a><span class="w"> </span><span class="n">capacity</span><span class="w"> </span><span class="o">*=</span><span class="w"> </span><span class="n">extendRatio</span><span class="p">;</span>
<a id="__codelineno-13-100" name="__codelineno-13-100" href="#__codelineno-13-100"></a><span class="w"> </span><span class="n">buckets</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">vector</span><span class="o">&lt;</span><span class="n">Pair</span><span class="w"> </span><span class="o">*&gt;</span><span class="p">(</span><span class="n">capacity</span><span class="p">,</span><span class="w"> </span><span class="k">nullptr</span><span class="p">);</span>
<a id="__codelineno-13-101" name="__codelineno-13-101" href="#__codelineno-13-101"></a><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-13-102" name="__codelineno-13-102" href="#__codelineno-13-102"></a><span class="w"> </span><span class="c1">// 将键值对从原哈希表搬运至新哈希表</span>
<a id="__codelineno-13-103" name="__codelineno-13-103" href="#__codelineno-13-103"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="n">Pair</span><span class="w"> </span><span class="o">*</span><span class="n">pair</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">bucketsTmp</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-104" name="__codelineno-13-104" href="#__codelineno-13-104"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">pair</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">nullptr</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">pair</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="n">removed</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-105" name="__codelineno-13-105" href="#__codelineno-13-105"></a><span class="w"> </span><span class="n">put</span><span class="p">(</span><span class="n">pair</span><span class="o">-&gt;</span><span class="n">key</span><span class="p">,</span><span class="w"> </span><span class="n">pair</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">);</span>
<a id="__codelineno-13-106" name="__codelineno-13-106" href="#__codelineno-13-106"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-107" name="__codelineno-13-107" href="#__codelineno-13-107"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-108" name="__codelineno-13-108" href="#__codelineno-13-108"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-109" name="__codelineno-13-109" href="#__codelineno-13-109"></a>
<a id="__codelineno-13-110" name="__codelineno-13-110" href="#__codelineno-13-110"></a><span class="w"> </span><span class="cm">/* 打印哈希表 */</span>
<a id="__codelineno-13-111" name="__codelineno-13-111" href="#__codelineno-13-111"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">print</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-112" name="__codelineno-13-112" href="#__codelineno-13-112"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="k">auto</span><span class="w"> </span><span class="o">&amp;</span><span class="n">pair</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">buckets</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-113" name="__codelineno-13-113" href="#__codelineno-13-113"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">pair</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-114" name="__codelineno-13-114" href="#__codelineno-13-114"></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="n">pair</span><span class="o">-&gt;</span><span class="n">key</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="s">&quot; -&gt; &quot;</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="n">pair</span><span class="o">-&gt;</span><span class="n">val</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-13-115" name="__codelineno-13-115" href="#__codelineno-13-115"></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-13-116" name="__codelineno-13-116" href="#__codelineno-13-116"></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="s">&quot;nullptr&quot;</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-13-117" name="__codelineno-13-117" href="#__codelineno-13-117"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-118" name="__codelineno-13-118" href="#__codelineno-13-118"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-119" name="__codelineno-13-119" href="#__codelineno-13-119"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-120" name="__codelineno-13-120" href="#__codelineno-13-120"></a><span class="p">};</span>
<a id="__codelineno-13-33" name="__codelineno-13-33" href="#__codelineno-13-33"></a><span class="w"> </span><span class="cm">/* 哈希函数 */</span>
<a id="__codelineno-13-34" name="__codelineno-13-34" href="#__codelineno-13-34"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">hashFunc</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-35" name="__codelineno-13-35" href="#__codelineno-13-35"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">key</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-13-36" name="__codelineno-13-36" href="#__codelineno-13-36"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-37" name="__codelineno-13-37" href="#__codelineno-13-37"></a>
<a id="__codelineno-13-38" name="__codelineno-13-38" href="#__codelineno-13-38"></a><span class="w"> </span><span class="cm">/* 负载因子 */</span>
<a id="__codelineno-13-39" name="__codelineno-13-39" href="#__codelineno-13-39"></a><span class="w"> </span><span class="kt">double</span><span class="w"> </span><span class="n">loadFactor</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-40" name="__codelineno-13-40" href="#__codelineno-13-40"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">(</span><span class="kt">double</span><span class="p">)</span><span class="n">size</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-13-41" name="__codelineno-13-41" href="#__codelineno-13-41"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-42" name="__codelineno-13-42" href="#__codelineno-13-42"></a>
<a id="__codelineno-13-43" name="__codelineno-13-43" href="#__codelineno-13-43"></a><span class="w"> </span><span class="cm">/* 搜索 key 对应的桶索引 */</span>
<a id="__codelineno-13-44" name="__codelineno-13-44" href="#__codelineno-13-44"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">findBucket</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-45" name="__codelineno-13-45" href="#__codelineno-13-45"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">hashFunc</span><span class="p">(</span><span class="n">key</span><span class="p">);</span>
<a id="__codelineno-13-46" name="__codelineno-13-46" href="#__codelineno-13-46"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">firstTombstone</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">-1</span><span class="p">;</span>
<a id="__codelineno-13-47" name="__codelineno-13-47" href="#__codelineno-13-47"></a><span class="w"> </span><span class="c1">// 线性探测,当遇到空桶时跳出</span>
<a id="__codelineno-13-48" name="__codelineno-13-48" href="#__codelineno-13-48"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-49" name="__codelineno-13-49" href="#__codelineno-13-49"></a><span class="w"> </span><span class="c1">// 若遇到 key ,返回对应桶索引</span>
<a id="__codelineno-13-50" name="__codelineno-13-50" href="#__codelineno-13-50"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="o">-&gt;</span><span class="n">key</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-51" name="__codelineno-13-51" href="#__codelineno-13-51"></a><span class="w"> </span><span class="c1">// 若之前遇到了删除标记,则将键值对移动至该索引</span>
<a id="__codelineno-13-52" name="__codelineno-13-52" href="#__codelineno-13-52"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">firstTombstone</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="mi">-1</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-53" name="__codelineno-13-53" href="#__codelineno-13-53"></a><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">firstTombstone</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">];</span>
<a id="__codelineno-13-54" name="__codelineno-13-54" href="#__codelineno-13-54"></a><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">;</span>
<a id="__codelineno-13-55" name="__codelineno-13-55" href="#__codelineno-13-55"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">firstTombstone</span><span class="p">;</span><span class="w"> </span><span class="c1">// 返回移动后的桶索引</span>
<a id="__codelineno-13-56" name="__codelineno-13-56" href="#__codelineno-13-56"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-57" name="__codelineno-13-57" href="#__codelineno-13-57"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">index</span><span class="p">;</span><span class="w"> </span><span class="c1">// 返回桶索引</span>
<a id="__codelineno-13-58" name="__codelineno-13-58" href="#__codelineno-13-58"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-59" name="__codelineno-13-59" href="#__codelineno-13-59"></a><span class="w"> </span><span class="c1">// 记录遇到的首个删除标记</span>
<a id="__codelineno-13-60" name="__codelineno-13-60" href="#__codelineno-13-60"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">firstTombstone</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">-1</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-61" name="__codelineno-13-61" href="#__codelineno-13-61"></a><span class="w"> </span><span class="n">firstTombstone</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">;</span>
<a id="__codelineno-13-62" name="__codelineno-13-62" href="#__codelineno-13-62"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-63" name="__codelineno-13-63" href="#__codelineno-13-63"></a><span class="w"> </span><span class="c1">// 计算桶索引,越过尾部返回头部</span>
<a id="__codelineno-13-64" name="__codelineno-13-64" href="#__codelineno-13-64"></a><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="n">index</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-13-65" name="__codelineno-13-65" href="#__codelineno-13-65"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-66" name="__codelineno-13-66" href="#__codelineno-13-66"></a><span class="w"> </span><span class="c1">// 若 key 不存在,则返回添加点的索引</span>
<a id="__codelineno-13-67" name="__codelineno-13-67" href="#__codelineno-13-67"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">firstTombstone</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">-1</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">firstTombstone</span><span class="p">;</span>
<a id="__codelineno-13-68" name="__codelineno-13-68" href="#__codelineno-13-68"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-69" name="__codelineno-13-69" href="#__codelineno-13-69"></a>
<a id="__codelineno-13-70" name="__codelineno-13-70" href="#__codelineno-13-70"></a><span class="w"> </span><span class="cm">/* 查询操作 */</span>
<a id="__codelineno-13-71" name="__codelineno-13-71" href="#__codelineno-13-71"></a><span class="w"> </span><span class="n">string</span><span class="w"> </span><span class="n">get</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-72" name="__codelineno-13-72" href="#__codelineno-13-72"></a><span class="w"> </span><span class="c1">// 搜索 key 对应的桶索引</span>
<a id="__codelineno-13-73" name="__codelineno-13-73" href="#__codelineno-13-73"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">findBucket</span><span class="p">(</span><span class="n">key</span><span class="p">);</span>
<a id="__codelineno-13-74" name="__codelineno-13-74" href="#__codelineno-13-74"></a><span class="w"> </span><span class="c1">// 若找到键值对,则返回对应 val</span>
<a id="__codelineno-13-75" name="__codelineno-13-75" href="#__codelineno-13-75"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">nullptr</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-76" name="__codelineno-13-76" href="#__codelineno-13-76"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-13-77" name="__codelineno-13-77" href="#__codelineno-13-77"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-78" name="__codelineno-13-78" href="#__codelineno-13-78"></a><span class="w"> </span><span class="c1">// 若键值对不存在,则返回空字符串</span>
<a id="__codelineno-13-79" name="__codelineno-13-79" href="#__codelineno-13-79"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="s">&quot;&quot;</span><span class="p">;</span>
<a id="__codelineno-13-80" name="__codelineno-13-80" href="#__codelineno-13-80"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-81" name="__codelineno-13-81" href="#__codelineno-13-81"></a>
<a id="__codelineno-13-82" name="__codelineno-13-82" href="#__codelineno-13-82"></a><span class="w"> </span><span class="cm">/* 添加操作 */</span>
<a id="__codelineno-13-83" name="__codelineno-13-83" href="#__codelineno-13-83"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">put</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">,</span><span class="w"> </span><span class="n">string</span><span class="w"> </span><span class="n">val</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-84" name="__codelineno-13-84" href="#__codelineno-13-84"></a><span class="w"> </span><span class="c1">// 当负载因子超过阈值时,执行扩容</span>
<a id="__codelineno-13-85" name="__codelineno-13-85" href="#__codelineno-13-85"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">loadFactor</span><span class="p">()</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">loadThres</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-86" name="__codelineno-13-86" href="#__codelineno-13-86"></a><span class="w"> </span><span class="n">extend</span><span class="p">();</span>
<a id="__codelineno-13-87" name="__codelineno-13-87" href="#__codelineno-13-87"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-88" name="__codelineno-13-88" href="#__codelineno-13-88"></a><span class="w"> </span><span class="c1">// 搜索 key 对应的桶索引</span>
<a id="__codelineno-13-89" name="__codelineno-13-89" href="#__codelineno-13-89"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">findBucket</span><span class="p">(</span><span class="n">key</span><span class="p">);</span>
<a id="__codelineno-13-90" name="__codelineno-13-90" href="#__codelineno-13-90"></a><span class="w"> </span><span class="c1">// 若找到键值对,则覆盖 val 并返回</span>
<a id="__codelineno-13-91" name="__codelineno-13-91" href="#__codelineno-13-91"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">nullptr</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-92" name="__codelineno-13-92" href="#__codelineno-13-92"></a><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="o">-&gt;</span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-13-93" name="__codelineno-13-93" href="#__codelineno-13-93"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-13-94" name="__codelineno-13-94" href="#__codelineno-13-94"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-95" name="__codelineno-13-95" href="#__codelineno-13-95"></a><span class="w"> </span><span class="c1">// 若键值对不存在,则添加该键值对</span>
<a id="__codelineno-13-96" name="__codelineno-13-96" href="#__codelineno-13-96"></a><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">Pair</span><span class="p">(</span><span class="n">key</span><span class="p">,</span><span class="w"> </span><span class="n">val</span><span class="p">);</span>
<a id="__codelineno-13-97" name="__codelineno-13-97" href="#__codelineno-13-97"></a><span class="w"> </span><span class="n">size</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-13-98" name="__codelineno-13-98" href="#__codelineno-13-98"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-99" name="__codelineno-13-99" href="#__codelineno-13-99"></a>
<a id="__codelineno-13-100" name="__codelineno-13-100" href="#__codelineno-13-100"></a><span class="w"> </span><span class="cm">/* 删除操作 */</span>
<a id="__codelineno-13-101" name="__codelineno-13-101" href="#__codelineno-13-101"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">remove</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-102" name="__codelineno-13-102" href="#__codelineno-13-102"></a><span class="w"> </span><span class="c1">// 搜索 key 对应的桶索引</span>
<a id="__codelineno-13-103" name="__codelineno-13-103" href="#__codelineno-13-103"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">findBucket</span><span class="p">(</span><span class="n">key</span><span class="p">);</span>
<a id="__codelineno-13-104" name="__codelineno-13-104" href="#__codelineno-13-104"></a><span class="w"> </span><span class="c1">// 若找到键值对,则用删除标记覆盖它</span>
<a id="__codelineno-13-105" name="__codelineno-13-105" href="#__codelineno-13-105"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">nullptr</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-106" name="__codelineno-13-106" href="#__codelineno-13-106"></a><span class="w"> </span><span class="k">delete</span><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">];</span>
<a id="__codelineno-13-107" name="__codelineno-13-107" href="#__codelineno-13-107"></a><span class="w"> </span><span class="n">buckets</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">;</span>
<a id="__codelineno-13-108" name="__codelineno-13-108" href="#__codelineno-13-108"></a><span class="w"> </span><span class="n">size</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-13-109" name="__codelineno-13-109" href="#__codelineno-13-109"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-110" name="__codelineno-13-110" href="#__codelineno-13-110"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-111" name="__codelineno-13-111" href="#__codelineno-13-111"></a>
<a id="__codelineno-13-112" name="__codelineno-13-112" href="#__codelineno-13-112"></a><span class="w"> </span><span class="cm">/* 扩容哈希表 */</span>
<a id="__codelineno-13-113" name="__codelineno-13-113" href="#__codelineno-13-113"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">extend</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-114" name="__codelineno-13-114" href="#__codelineno-13-114"></a><span class="w"> </span><span class="c1">// 暂存原哈希表</span>
<a id="__codelineno-13-115" name="__codelineno-13-115" href="#__codelineno-13-115"></a><span class="w"> </span><span class="n">vector</span><span class="o">&lt;</span><span class="n">Pair</span><span class="w"> </span><span class="o">*&gt;</span><span class="w"> </span><span class="n">bucketsTmp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">buckets</span><span class="p">;</span>
<a id="__codelineno-13-116" name="__codelineno-13-116" href="#__codelineno-13-116"></a><span class="w"> </span><span class="c1">// 初始化扩容后的新哈希表</span>
<a id="__codelineno-13-117" name="__codelineno-13-117" href="#__codelineno-13-117"></a><span class="w"> </span><span class="n">capacity</span><span class="w"> </span><span class="o">*=</span><span class="w"> </span><span class="n">extendRatio</span><span class="p">;</span>
<a id="__codelineno-13-118" name="__codelineno-13-118" href="#__codelineno-13-118"></a><span class="w"> </span><span class="n">buckets</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">vector</span><span class="o">&lt;</span><span class="n">Pair</span><span class="w"> </span><span class="o">*&gt;</span><span class="p">(</span><span class="n">capacity</span><span class="p">,</span><span class="w"> </span><span class="k">nullptr</span><span class="p">);</span>
<a id="__codelineno-13-119" name="__codelineno-13-119" href="#__codelineno-13-119"></a><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-13-120" name="__codelineno-13-120" href="#__codelineno-13-120"></a><span class="w"> </span><span class="c1">// 将键值对从原哈希表搬运至新哈希表</span>
<a id="__codelineno-13-121" name="__codelineno-13-121" href="#__codelineno-13-121"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="n">Pair</span><span class="w"> </span><span class="o">*</span><span class="n">pair</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">bucketsTmp</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-122" name="__codelineno-13-122" href="#__codelineno-13-122"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">pair</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">nullptr</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">pair</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-123" name="__codelineno-13-123" href="#__codelineno-13-123"></a><span class="w"> </span><span class="n">put</span><span class="p">(</span><span class="n">pair</span><span class="o">-&gt;</span><span class="n">key</span><span class="p">,</span><span class="w"> </span><span class="n">pair</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">);</span>
<a id="__codelineno-13-124" name="__codelineno-13-124" href="#__codelineno-13-124"></a><span class="w"> </span><span class="k">delete</span><span class="w"> </span><span class="n">pair</span><span class="p">;</span>
<a id="__codelineno-13-125" name="__codelineno-13-125" href="#__codelineno-13-125"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-126" name="__codelineno-13-126" href="#__codelineno-13-126"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-127" name="__codelineno-13-127" href="#__codelineno-13-127"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-128" name="__codelineno-13-128" href="#__codelineno-13-128"></a>
<a id="__codelineno-13-129" name="__codelineno-13-129" href="#__codelineno-13-129"></a><span class="w"> </span><span class="cm">/* 打印哈希表 */</span>
<a id="__codelineno-13-130" name="__codelineno-13-130" href="#__codelineno-13-130"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">print</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-131" name="__codelineno-13-131" href="#__codelineno-13-131"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="n">Pair</span><span class="w"> </span><span class="o">*</span><span class="n">pair</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">buckets</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-132" name="__codelineno-13-132" href="#__codelineno-13-132"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">pair</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="k">nullptr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-133" name="__codelineno-13-133" href="#__codelineno-13-133"></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="s">&quot;nullptr&quot;</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-13-134" name="__codelineno-13-134" href="#__codelineno-13-134"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">pair</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-135" name="__codelineno-13-135" href="#__codelineno-13-135"></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="s">&quot;TOMBSTONE&quot;</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-13-136" name="__codelineno-13-136" href="#__codelineno-13-136"></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-13-137" name="__codelineno-13-137" href="#__codelineno-13-137"></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="n">pair</span><span class="o">-&gt;</span><span class="n">key</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="s">&quot; -&gt; &quot;</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="n">pair</span><span class="o">-&gt;</span><span class="n">val</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-13-138" name="__codelineno-13-138" href="#__codelineno-13-138"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-139" name="__codelineno-13-139" href="#__codelineno-13-139"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-140" name="__codelineno-13-140" href="#__codelineno-13-140"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-141" name="__codelineno-13-141" href="#__codelineno-13-141"></a><span class="p">};</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">hash_map_open_addressing.java</span><pre><span></span><code><a id="__codelineno-14-1" name="__codelineno-14-1" href="#__codelineno-14-1"></a><span class="cm">/* 开放寻址哈希表 */</span>
<a id="__codelineno-14-2" name="__codelineno-14-2" href="#__codelineno-14-2"></a><span class="kd">class</span> <span class="nc">HashMapOpenAddressing</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-3" name="__codelineno-14-3" href="#__codelineno-14-3"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="p">;</span><span class="w"> </span><span class="c1">// 键值对数量</span>
<a id="__codelineno-14-4" name="__codelineno-14-4" href="#__codelineno-14-4"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span><span class="w"> </span><span class="c1">// 哈希表容量</span>
<a id="__codelineno-14-5" name="__codelineno-14-5" href="#__codelineno-14-5"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">double</span><span class="w"> </span><span class="n">loadThres</span><span class="p">;</span><span class="w"> </span><span class="c1">// 触发扩容的负载因子阈值</span>
<a id="__codelineno-14-6" name="__codelineno-14-6" href="#__codelineno-14-6"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">extendRatio</span><span class="p">;</span><span class="w"> </span><span class="c1">// 扩容倍数</span>
<a id="__codelineno-14-4" name="__codelineno-14-4" href="#__codelineno-14-4"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">4</span><span class="p">;</span><span class="w"> </span><span class="c1">// 哈希表容量</span>
<a id="__codelineno-14-5" name="__codelineno-14-5" href="#__codelineno-14-5"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kd">final</span><span class="w"> </span><span class="kt">double</span><span class="w"> </span><span class="n">loadThres</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">2.0</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mi">3</span><span class="p">;</span><span class="w"> </span><span class="c1">// 触发扩容的负载因子阈值</span>
<a id="__codelineno-14-6" name="__codelineno-14-6" href="#__codelineno-14-6"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kd">final</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">extendRatio</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">2</span><span class="p">;</span><span class="w"> </span><span class="c1">// 扩容倍数</span>
<a id="__codelineno-14-7" name="__codelineno-14-7" href="#__codelineno-14-7"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="n">Pair</span><span class="o">[]</span><span class="w"> </span><span class="n">buckets</span><span class="p">;</span><span class="w"> </span><span class="c1">// 桶数组</span>
<a id="__codelineno-14-8" name="__codelineno-14-8" href="#__codelineno-14-8"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="n">Pair</span><span class="w"> </span><span class="n">removed</span><span class="p">;</span><span class="w"> </span><span class="c1">// 删除标记</span>
<a id="__codelineno-14-8" name="__codelineno-14-8" href="#__codelineno-14-8"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kd">final</span><span class="w"> </span><span class="n">Pair</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">Pair</span><span class="p">(</span><span class="o">-</span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="s">&quot;-1&quot;</span><span class="p">);</span><span class="w"> </span><span class="c1">// 删除标记</span>
<a id="__codelineno-14-9" name="__codelineno-14-9" href="#__codelineno-14-9"></a>
<a id="__codelineno-14-10" name="__codelineno-14-10" href="#__codelineno-14-10"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-14-11" name="__codelineno-14-11" href="#__codelineno-14-11"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="nf">HashMapOpenAddressing</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-12" name="__codelineno-14-12" href="#__codelineno-14-12"></a><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-14-13" name="__codelineno-14-13" href="#__codelineno-14-13"></a><span class="w"> </span><span class="n">capacity</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">4</span><span class="p">;</span>
<a id="__codelineno-14-14" name="__codelineno-14-14" href="#__codelineno-14-14"></a><span class="w"> </span><span class="n">loadThres</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">2.0</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">3.0</span><span class="p">;</span>
<a id="__codelineno-14-15" name="__codelineno-14-15" href="#__codelineno-14-15"></a><span class="w"> </span><span class="n">extendRatio</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">2</span><span class="p">;</span>
<a id="__codelineno-14-16" name="__codelineno-14-16" href="#__codelineno-14-16"></a><span class="w"> </span><span class="n">buckets</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">Pair</span><span class="o">[</span><span class="n">capacity</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-14-17" name="__codelineno-14-17" href="#__codelineno-14-17"></a><span class="w"> </span><span class="n">removed</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">Pair</span><span class="p">(</span><span class="o">-</span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="s">&quot;-1&quot;</span><span class="p">);</span>
<a id="__codelineno-14-18" name="__codelineno-14-18" href="#__codelineno-14-18"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-19" name="__codelineno-14-19" href="#__codelineno-14-19"></a>
<a id="__codelineno-14-20" name="__codelineno-14-20" href="#__codelineno-14-20"></a><span class="w"> </span><span class="cm">/* 哈希函数 */</span>
<a id="__codelineno-14-21" name="__codelineno-14-21" href="#__codelineno-14-21"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">hashFunc</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-22" name="__codelineno-14-22" href="#__codelineno-14-22"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">key</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-14-23" name="__codelineno-14-23" href="#__codelineno-14-23"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-24" name="__codelineno-14-24" href="#__codelineno-14-24"></a>
<a id="__codelineno-14-25" name="__codelineno-14-25" href="#__codelineno-14-25"></a><span class="w"> </span><span class="cm">/* 负载因子 */</span>
<a id="__codelineno-14-26" name="__codelineno-14-26" href="#__codelineno-14-26"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">double</span><span class="w"> </span><span class="nf">loadFactor</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-27" name="__codelineno-14-27" href="#__codelineno-14-27"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">(</span><span class="kt">double</span><span class="p">)</span><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-14-28" name="__codelineno-14-28" href="#__codelineno-14-28"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-29" name="__codelineno-14-29" href="#__codelineno-14-29"></a>
<a id="__codelineno-14-30" name="__codelineno-14-30" href="#__codelineno-14-30"></a><span class="w"> </span><span class="cm">/* 查询操作 */</span>
<a id="__codelineno-14-31" name="__codelineno-14-31" href="#__codelineno-14-31"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="n">String</span><span class="w"> </span><span class="nf">get</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-32" name="__codelineno-14-32" href="#__codelineno-14-32"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">hashFunc</span><span class="p">(</span><span class="n">key</span><span class="p">);</span>
<a id="__codelineno-14-33" name="__codelineno-14-33" href="#__codelineno-14-33"></a><span class="w"> </span><span class="c1">// 线性探测,从 index 开始向后遍历</span>
<a id="__codelineno-14-34" name="__codelineno-14-34" href="#__codelineno-14-34"></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">capacity</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-14-35" name="__codelineno-14-35" href="#__codelineno-14-35"></a><span class="w"> </span><span class="c1">// 计算桶索引,越过尾部返回头部</span>
<a id="__codelineno-14-36" name="__codelineno-14-36" href="#__codelineno-14-36"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="n">index</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="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-14-37" name="__codelineno-14-37" href="#__codelineno-14-37"></a><span class="w"> </span><span class="c1">// 若遇到空桶,说明无此 key ,则返回 null</span>
<a id="__codelineno-14-38" name="__codelineno-14-38" href="#__codelineno-14-38"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="o">[</span><span class="n">j</span><span class="o">]</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span>
<a id="__codelineno-14-39" name="__codelineno-14-39" href="#__codelineno-14-39"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-40" name="__codelineno-14-40" href="#__codelineno-14-40"></a><span class="w"> </span><span class="c1">// 若遇到指定 key ,则返回对应 val</span>
<a id="__codelineno-14-41" name="__codelineno-14-41" href="#__codelineno-14-41"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="o">[</span><span class="n">j</span><span class="o">]</span><span class="p">.</span><span class="na">key</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">key</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">j</span><span class="o">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="n">removed</span><span class="p">)</span>
<a id="__codelineno-14-42" name="__codelineno-14-42" href="#__codelineno-14-42"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">j</span><span class="o">]</span><span class="p">.</span><span class="na">val</span><span class="p">;</span>
<a id="__codelineno-14-43" name="__codelineno-14-43" href="#__codelineno-14-43"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-44" name="__codelineno-14-44" href="#__codelineno-14-44"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-45" name="__codelineno-14-45" href="#__codelineno-14-45"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-46" name="__codelineno-14-46" href="#__codelineno-14-46"></a>
<a id="__codelineno-14-47" name="__codelineno-14-47" href="#__codelineno-14-47"></a><span class="w"> </span><span class="cm">/* 添加操作 */</span>
<a id="__codelineno-14-48" name="__codelineno-14-48" href="#__codelineno-14-48"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">put</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">,</span><span class="w"> </span><span class="n">String</span><span class="w"> </span><span class="n">val</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-49" name="__codelineno-14-49" href="#__codelineno-14-49"></a><span class="w"> </span><span class="c1">// 当负载因子超过阈值时,执行扩容</span>
<a id="__codelineno-14-50" name="__codelineno-14-50" href="#__codelineno-14-50"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">loadFactor</span><span class="p">()</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">loadThres</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-51" name="__codelineno-14-51" href="#__codelineno-14-51"></a><span class="w"> </span><span class="n">extend</span><span class="p">();</span>
<a id="__codelineno-14-52" name="__codelineno-14-52" href="#__codelineno-14-52"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-53" name="__codelineno-14-53" href="#__codelineno-14-53"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">hashFunc</span><span class="p">(</span><span class="n">key</span><span class="p">);</span>
<a id="__codelineno-14-54" name="__codelineno-14-54" href="#__codelineno-14-54"></a><span class="w"> </span><span class="c1">// 线性探测,从 index 开始向后遍历</span>
<a id="__codelineno-14-55" name="__codelineno-14-55" href="#__codelineno-14-55"></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">capacity</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-14-56" name="__codelineno-14-56" href="#__codelineno-14-56"></a><span class="w"> </span><span class="c1">// 计算桶索引,越过尾部返回头部</span>
<a id="__codelineno-14-57" name="__codelineno-14-57" href="#__codelineno-14-57"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="n">index</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="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-14-58" name="__codelineno-14-58" href="#__codelineno-14-58"></a><span class="w"> </span><span class="c1">// 若遇到空桶、或带有删除标记的桶,则将键值对放入该桶</span>
<a id="__codelineno-14-59" name="__codelineno-14-59" href="#__codelineno-14-59"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="o">[</span><span class="n">j</span><span class="o">]</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="kc">null</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">j</span><span class="o">]</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">removed</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-60" name="__codelineno-14-60" href="#__codelineno-14-60"></a><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">j</span><span class="o">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">Pair</span><span class="p">(</span><span class="n">key</span><span class="p">,</span><span class="w"> </span><span class="n">val</span><span class="p">);</span>
<a id="__codelineno-14-61" name="__codelineno-14-61" href="#__codelineno-14-61"></a><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">+=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
<a id="__codelineno-14-62" name="__codelineno-14-62" href="#__codelineno-14-62"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-14-63" name="__codelineno-14-63" href="#__codelineno-14-63"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-64" name="__codelineno-14-64" href="#__codelineno-14-64"></a><span class="w"> </span><span class="c1">// 若遇到指定 key ,则更新对应 val</span>
<a id="__codelineno-14-65" name="__codelineno-14-65" href="#__codelineno-14-65"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="o">[</span><span class="n">j</span><span class="o">]</span><span class="p">.</span><span class="na">key</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-66" name="__codelineno-14-66" href="#__codelineno-14-66"></a><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">j</span><span class="o">]</span><span class="p">.</span><span class="na">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-14-67" name="__codelineno-14-67" href="#__codelineno-14-67"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-14-68" name="__codelineno-14-68" href="#__codelineno-14-68"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-69" name="__codelineno-14-69" href="#__codelineno-14-69"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-70" name="__codelineno-14-70" href="#__codelineno-14-70"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-71" name="__codelineno-14-71" href="#__codelineno-14-71"></a>
<a id="__codelineno-14-72" name="__codelineno-14-72" href="#__codelineno-14-72"></a><span class="w"> </span><span class="cm">/* 删除操作 */</span>
<a id="__codelineno-14-73" name="__codelineno-14-73" href="#__codelineno-14-73"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">remove</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-74" name="__codelineno-14-74" href="#__codelineno-14-74"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">hashFunc</span><span class="p">(</span><span class="n">key</span><span class="p">);</span>
<a id="__codelineno-14-75" name="__codelineno-14-75" href="#__codelineno-14-75"></a><span class="w"> </span><span class="c1">// 线性探测,从 index 开始向后遍历</span>
<a id="__codelineno-14-76" name="__codelineno-14-76" href="#__codelineno-14-76"></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">capacity</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-14-77" name="__codelineno-14-77" href="#__codelineno-14-77"></a><span class="w"> </span><span class="c1">// 计算桶索引,越过尾部返回头部</span>
<a id="__codelineno-14-78" name="__codelineno-14-78" href="#__codelineno-14-78"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="n">index</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="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-14-79" name="__codelineno-14-79" href="#__codelineno-14-79"></a><span class="w"> </span><span class="c1">// 若遇到空桶,说明无此 key ,则直接返回</span>
<a id="__codelineno-14-80" name="__codelineno-14-80" href="#__codelineno-14-80"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="o">[</span><span class="n">j</span><span class="o">]</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-81" name="__codelineno-14-81" href="#__codelineno-14-81"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-14-82" name="__codelineno-14-82" href="#__codelineno-14-82"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-83" name="__codelineno-14-83" href="#__codelineno-14-83"></a><span class="w"> </span><span class="c1">// 若遇到指定 key ,则标记删除并返回</span>
<a id="__codelineno-14-84" name="__codelineno-14-84" href="#__codelineno-14-84"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="o">[</span><span class="n">j</span><span class="o">]</span><span class="p">.</span><span class="na">key</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-85" name="__codelineno-14-85" href="#__codelineno-14-85"></a><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">j</span><span class="o">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">removed</span><span class="p">;</span>
<a id="__codelineno-14-86" name="__codelineno-14-86" href="#__codelineno-14-86"></a><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">-=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
<a id="__codelineno-14-87" name="__codelineno-14-87" href="#__codelineno-14-87"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-14-88" name="__codelineno-14-88" href="#__codelineno-14-88"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-89" name="__codelineno-14-89" href="#__codelineno-14-89"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-90" name="__codelineno-14-90" href="#__codelineno-14-90"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-91" name="__codelineno-14-91" href="#__codelineno-14-91"></a>
<a id="__codelineno-14-92" name="__codelineno-14-92" href="#__codelineno-14-92"></a><span class="w"> </span><span class="cm">/* 扩容哈希表 */</span>
<a id="__codelineno-14-93" name="__codelineno-14-93" href="#__codelineno-14-93"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">extend</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-94" name="__codelineno-14-94" href="#__codelineno-14-94"></a><span class="w"> </span><span class="c1">// 暂存原哈希表</span>
<a id="__codelineno-14-95" name="__codelineno-14-95" href="#__codelineno-14-95"></a><span class="w"> </span><span class="n">Pair</span><span class="o">[]</span><span class="w"> </span><span class="n">bucketsTmp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">buckets</span><span class="p">;</span>
<a id="__codelineno-14-96" name="__codelineno-14-96" href="#__codelineno-14-96"></a><span class="w"> </span><span class="c1">// 初始化扩容后的新哈希表</span>
<a id="__codelineno-14-97" name="__codelineno-14-97" href="#__codelineno-14-97"></a><span class="w"> </span><span class="n">capacity</span><span class="w"> </span><span class="o">*=</span><span class="w"> </span><span class="n">extendRatio</span><span class="p">;</span>
<a id="__codelineno-14-98" name="__codelineno-14-98" href="#__codelineno-14-98"></a><span class="w"> </span><span class="n">buckets</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">Pair</span><span class="o">[</span><span class="n">capacity</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-14-99" name="__codelineno-14-99" href="#__codelineno-14-99"></a><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-14-100" name="__codelineno-14-100" href="#__codelineno-14-100"></a><span class="w"> </span><span class="c1">// 将键值对从原哈希表搬运至新哈希表</span>
<a id="__codelineno-14-101" name="__codelineno-14-101" href="#__codelineno-14-101"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="n">Pair</span><span class="w"> </span><span class="n">pair</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">bucketsTmp</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-102" name="__codelineno-14-102" href="#__codelineno-14-102"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">pair</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">pair</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="n">removed</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-103" name="__codelineno-14-103" href="#__codelineno-14-103"></a><span class="w"> </span><span class="n">put</span><span class="p">(</span><span class="n">pair</span><span class="p">.</span><span class="na">key</span><span class="p">,</span><span class="w"> </span><span class="n">pair</span><span class="p">.</span><span class="na">val</span><span class="p">);</span>
<a id="__codelineno-14-104" name="__codelineno-14-104" href="#__codelineno-14-104"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-105" name="__codelineno-14-105" href="#__codelineno-14-105"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-106" name="__codelineno-14-106" href="#__codelineno-14-106"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-107" name="__codelineno-14-107" href="#__codelineno-14-107"></a>
<a id="__codelineno-14-108" name="__codelineno-14-108" href="#__codelineno-14-108"></a><span class="w"> </span><span class="cm">/* 打印哈希表 */</span>
<a id="__codelineno-14-109" name="__codelineno-14-109" href="#__codelineno-14-109"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">print</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-110" name="__codelineno-14-110" href="#__codelineno-14-110"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="n">Pair</span><span class="w"> </span><span class="n">pair</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">buckets</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-111" name="__codelineno-14-111" href="#__codelineno-14-111"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">pair</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-112" name="__codelineno-14-112" href="#__codelineno-14-112"></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="n">pair</span><span class="p">.</span><span class="na">key</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s">&quot; -&gt; &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">pair</span><span class="p">.</span><span class="na">val</span><span class="p">);</span>
<a id="__codelineno-14-113" name="__codelineno-14-113" href="#__codelineno-14-113"></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-14-13" name="__codelineno-14-13" href="#__codelineno-14-13"></a><span class="w"> </span><span class="n">buckets</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">Pair</span><span class="o">[</span><span class="n">capacity</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-14-14" name="__codelineno-14-14" href="#__codelineno-14-14"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-15" name="__codelineno-14-15" href="#__codelineno-14-15"></a>
<a id="__codelineno-14-16" name="__codelineno-14-16" href="#__codelineno-14-16"></a><span class="w"> </span><span class="cm">/* 哈希函数 */</span>
<a id="__codelineno-14-17" name="__codelineno-14-17" href="#__codelineno-14-17"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">hashFunc</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-18" name="__codelineno-14-18" href="#__codelineno-14-18"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">key</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-14-19" name="__codelineno-14-19" href="#__codelineno-14-19"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-20" name="__codelineno-14-20" href="#__codelineno-14-20"></a>
<a id="__codelineno-14-21" name="__codelineno-14-21" href="#__codelineno-14-21"></a><span class="w"> </span><span class="cm">/* 负载因子 */</span>
<a id="__codelineno-14-22" name="__codelineno-14-22" href="#__codelineno-14-22"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">double</span><span class="w"> </span><span class="nf">loadFactor</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-23" name="__codelineno-14-23" href="#__codelineno-14-23"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">(</span><span class="kt">double</span><span class="p">)</span><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-14-24" name="__codelineno-14-24" href="#__codelineno-14-24"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-25" name="__codelineno-14-25" href="#__codelineno-14-25"></a>
<a id="__codelineno-14-26" name="__codelineno-14-26" href="#__codelineno-14-26"></a><span class="w"> </span><span class="cm">/* 搜索 key 对应的桶索引 */</span>
<a id="__codelineno-14-27" name="__codelineno-14-27" href="#__codelineno-14-27"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">findBucket</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-28" name="__codelineno-14-28" href="#__codelineno-14-28"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">hashFunc</span><span class="p">(</span><span class="n">key</span><span class="p">);</span>
<a id="__codelineno-14-29" name="__codelineno-14-29" href="#__codelineno-14-29"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">firstTombstone</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="o">-</span><span class="mi">1</span><span class="p">;</span>
<a id="__codelineno-14-30" name="__codelineno-14-30" href="#__codelineno-14-30"></a><span class="w"> </span><span class="c1">// 线性探测,当遇到空桶时跳出</span>
<a id="__codelineno-14-31" name="__codelineno-14-31" href="#__codelineno-14-31"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="o">[</span><span class="n">index</span><span class="o">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-32" name="__codelineno-14-32" href="#__codelineno-14-32"></a><span class="w"> </span><span class="c1">// 若遇到 key ,返回对应桶索引</span>
<a id="__codelineno-14-33" name="__codelineno-14-33" href="#__codelineno-14-33"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="o">[</span><span class="n">index</span><span class="o">]</span><span class="p">.</span><span class="na">key</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-34" name="__codelineno-14-34" href="#__codelineno-14-34"></a><span class="w"> </span><span class="c1">// 若之前遇到了删除标记,则将键值对移动至该索引</span>
<a id="__codelineno-14-35" name="__codelineno-14-35" href="#__codelineno-14-35"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">firstTombstone</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="o">-</span><span class="mi">1</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-36" name="__codelineno-14-36" href="#__codelineno-14-36"></a><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">firstTombstone</span><span class="o">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">index</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-14-37" name="__codelineno-14-37" href="#__codelineno-14-37"></a><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">index</span><span class="o">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">;</span>
<a id="__codelineno-14-38" name="__codelineno-14-38" href="#__codelineno-14-38"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">firstTombstone</span><span class="p">;</span><span class="w"> </span><span class="c1">// 返回移动后的桶索引</span>
<a id="__codelineno-14-39" name="__codelineno-14-39" href="#__codelineno-14-39"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-40" name="__codelineno-14-40" href="#__codelineno-14-40"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">index</span><span class="p">;</span><span class="w"> </span><span class="c1">// 返回桶索引</span>
<a id="__codelineno-14-41" name="__codelineno-14-41" href="#__codelineno-14-41"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-42" name="__codelineno-14-42" href="#__codelineno-14-42"></a><span class="w"> </span><span class="c1">// 记录遇到的首个删除标记</span>
<a id="__codelineno-14-43" name="__codelineno-14-43" href="#__codelineno-14-43"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">firstTombstone</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="o">-</span><span class="mi">1</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">index</span><span class="o">]</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-44" name="__codelineno-14-44" href="#__codelineno-14-44"></a><span class="w"> </span><span class="n">firstTombstone</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">;</span>
<a id="__codelineno-14-45" name="__codelineno-14-45" href="#__codelineno-14-45"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-46" name="__codelineno-14-46" href="#__codelineno-14-46"></a><span class="w"> </span><span class="c1">// 计算桶索引,越过尾部返回头部</span>
<a id="__codelineno-14-47" name="__codelineno-14-47" href="#__codelineno-14-47"></a><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="n">index</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-14-48" name="__codelineno-14-48" href="#__codelineno-14-48"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-49" name="__codelineno-14-49" href="#__codelineno-14-49"></a><span class="w"> </span><span class="c1">// 若 key 不存在,则返回添加点的索引</span>
<a id="__codelineno-14-50" name="__codelineno-14-50" href="#__codelineno-14-50"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">firstTombstone</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="o">-</span><span class="mi">1</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">firstTombstone</span><span class="p">;</span>
<a id="__codelineno-14-51" name="__codelineno-14-51" href="#__codelineno-14-51"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-52" name="__codelineno-14-52" href="#__codelineno-14-52"></a>
<a id="__codelineno-14-53" name="__codelineno-14-53" href="#__codelineno-14-53"></a><span class="w"> </span><span class="cm">/* 查询操作 */</span>
<a id="__codelineno-14-54" name="__codelineno-14-54" href="#__codelineno-14-54"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="n">String</span><span class="w"> </span><span class="nf">get</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-55" name="__codelineno-14-55" href="#__codelineno-14-55"></a><span class="w"> </span><span class="c1">// 搜索 key 对应的桶索引</span>
<a id="__codelineno-14-56" name="__codelineno-14-56" href="#__codelineno-14-56"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">findBucket</span><span class="p">(</span><span class="n">key</span><span class="p">);</span>
<a id="__codelineno-14-57" name="__codelineno-14-57" href="#__codelineno-14-57"></a><span class="w"> </span><span class="c1">// 若找到键值对,则返回对应 val</span>
<a id="__codelineno-14-58" name="__codelineno-14-58" href="#__codelineno-14-58"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="o">[</span><span class="n">index</span><span class="o">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">index</span><span class="o">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-59" name="__codelineno-14-59" href="#__codelineno-14-59"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">index</span><span class="o">]</span><span class="p">.</span><span class="na">val</span><span class="p">;</span>
<a id="__codelineno-14-60" name="__codelineno-14-60" href="#__codelineno-14-60"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-61" name="__codelineno-14-61" href="#__codelineno-14-61"></a><span class="w"> </span><span class="c1">// 若键值对不存在,则返回 null</span>
<a id="__codelineno-14-62" name="__codelineno-14-62" href="#__codelineno-14-62"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-63" name="__codelineno-14-63" href="#__codelineno-14-63"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-64" name="__codelineno-14-64" href="#__codelineno-14-64"></a>
<a id="__codelineno-14-65" name="__codelineno-14-65" href="#__codelineno-14-65"></a><span class="w"> </span><span class="cm">/* 添加操作 */</span>
<a id="__codelineno-14-66" name="__codelineno-14-66" href="#__codelineno-14-66"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">put</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">,</span><span class="w"> </span><span class="n">String</span><span class="w"> </span><span class="n">val</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-67" name="__codelineno-14-67" href="#__codelineno-14-67"></a><span class="w"> </span><span class="c1">// 当负载因子超过阈值时,执行扩容</span>
<a id="__codelineno-14-68" name="__codelineno-14-68" href="#__codelineno-14-68"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">loadFactor</span><span class="p">()</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">loadThres</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-69" name="__codelineno-14-69" href="#__codelineno-14-69"></a><span class="w"> </span><span class="n">extend</span><span class="p">();</span>
<a id="__codelineno-14-70" name="__codelineno-14-70" href="#__codelineno-14-70"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-71" name="__codelineno-14-71" href="#__codelineno-14-71"></a><span class="w"> </span><span class="c1">// 搜索 key 对应的桶索引</span>
<a id="__codelineno-14-72" name="__codelineno-14-72" href="#__codelineno-14-72"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">findBucket</span><span class="p">(</span><span class="n">key</span><span class="p">);</span>
<a id="__codelineno-14-73" name="__codelineno-14-73" href="#__codelineno-14-73"></a><span class="w"> </span><span class="c1">// 若找到键值对,则覆盖 val 并返回</span>
<a id="__codelineno-14-74" name="__codelineno-14-74" href="#__codelineno-14-74"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="o">[</span><span class="n">index</span><span class="o">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">index</span><span class="o">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-75" name="__codelineno-14-75" href="#__codelineno-14-75"></a><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">index</span><span class="o">]</span><span class="p">.</span><span class="na">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-14-76" name="__codelineno-14-76" href="#__codelineno-14-76"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-14-77" name="__codelineno-14-77" href="#__codelineno-14-77"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-78" name="__codelineno-14-78" href="#__codelineno-14-78"></a><span class="w"> </span><span class="c1">// 若键值对不存在,则添加该键值对</span>
<a id="__codelineno-14-79" name="__codelineno-14-79" href="#__codelineno-14-79"></a><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">index</span><span class="o">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">Pair</span><span class="p">(</span><span class="n">key</span><span class="p">,</span><span class="w"> </span><span class="n">val</span><span class="p">);</span>
<a id="__codelineno-14-80" name="__codelineno-14-80" href="#__codelineno-14-80"></a><span class="w"> </span><span class="n">size</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-14-81" name="__codelineno-14-81" href="#__codelineno-14-81"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-82" name="__codelineno-14-82" href="#__codelineno-14-82"></a>
<a id="__codelineno-14-83" name="__codelineno-14-83" href="#__codelineno-14-83"></a><span class="w"> </span><span class="cm">/* 删除操作 */</span>
<a id="__codelineno-14-84" name="__codelineno-14-84" href="#__codelineno-14-84"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">remove</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">key</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-85" name="__codelineno-14-85" href="#__codelineno-14-85"></a><span class="w"> </span><span class="c1">// 搜索 key 对应的桶索引</span>
<a id="__codelineno-14-86" name="__codelineno-14-86" href="#__codelineno-14-86"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">findBucket</span><span class="p">(</span><span class="n">key</span><span class="p">);</span>
<a id="__codelineno-14-87" name="__codelineno-14-87" href="#__codelineno-14-87"></a><span class="w"> </span><span class="c1">// 若找到键值对,则用删除标记覆盖它</span>
<a id="__codelineno-14-88" name="__codelineno-14-88" href="#__codelineno-14-88"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">buckets</span><span class="o">[</span><span class="n">index</span><span class="o">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">index</span><span class="o">]</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-89" name="__codelineno-14-89" href="#__codelineno-14-89"></a><span class="w"> </span><span class="n">buckets</span><span class="o">[</span><span class="n">index</span><span class="o">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">;</span>
<a id="__codelineno-14-90" name="__codelineno-14-90" href="#__codelineno-14-90"></a><span class="w"> </span><span class="n">size</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-14-91" name="__codelineno-14-91" href="#__codelineno-14-91"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-92" name="__codelineno-14-92" href="#__codelineno-14-92"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-93" name="__codelineno-14-93" href="#__codelineno-14-93"></a>
<a id="__codelineno-14-94" name="__codelineno-14-94" href="#__codelineno-14-94"></a><span class="w"> </span><span class="cm">/* 扩容哈希表 */</span>
<a id="__codelineno-14-95" name="__codelineno-14-95" href="#__codelineno-14-95"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">extend</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-96" name="__codelineno-14-96" href="#__codelineno-14-96"></a><span class="w"> </span><span class="c1">// 暂存原哈希表</span>
<a id="__codelineno-14-97" name="__codelineno-14-97" href="#__codelineno-14-97"></a><span class="w"> </span><span class="n">Pair</span><span class="o">[]</span><span class="w"> </span><span class="n">bucketsTmp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">buckets</span><span class="p">;</span>
<a id="__codelineno-14-98" name="__codelineno-14-98" href="#__codelineno-14-98"></a><span class="w"> </span><span class="c1">// 初始化扩容后的新哈希表</span>
<a id="__codelineno-14-99" name="__codelineno-14-99" href="#__codelineno-14-99"></a><span class="w"> </span><span class="n">capacity</span><span class="w"> </span><span class="o">*=</span><span class="w"> </span><span class="n">extendRatio</span><span class="p">;</span>
<a id="__codelineno-14-100" name="__codelineno-14-100" href="#__codelineno-14-100"></a><span class="w"> </span><span class="n">buckets</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">Pair</span><span class="o">[</span><span class="n">capacity</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-14-101" name="__codelineno-14-101" href="#__codelineno-14-101"></a><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-14-102" name="__codelineno-14-102" href="#__codelineno-14-102"></a><span class="w"> </span><span class="c1">// 将键值对从原哈希表搬运至新哈希表</span>
<a id="__codelineno-14-103" name="__codelineno-14-103" href="#__codelineno-14-103"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="n">Pair</span><span class="w"> </span><span class="n">pair</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">bucketsTmp</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-104" name="__codelineno-14-104" href="#__codelineno-14-104"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">pair</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">pair</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-105" name="__codelineno-14-105" href="#__codelineno-14-105"></a><span class="w"> </span><span class="n">put</span><span class="p">(</span><span class="n">pair</span><span class="p">.</span><span class="na">key</span><span class="p">,</span><span class="w"> </span><span class="n">pair</span><span class="p">.</span><span class="na">val</span><span class="p">);</span>
<a id="__codelineno-14-106" name="__codelineno-14-106" href="#__codelineno-14-106"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-107" name="__codelineno-14-107" href="#__codelineno-14-107"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-108" name="__codelineno-14-108" href="#__codelineno-14-108"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-109" name="__codelineno-14-109" href="#__codelineno-14-109"></a>
<a id="__codelineno-14-110" name="__codelineno-14-110" href="#__codelineno-14-110"></a><span class="w"> </span><span class="cm">/* 打印哈希表 */</span>
<a id="__codelineno-14-111" name="__codelineno-14-111" href="#__codelineno-14-111"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">print</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-112" name="__codelineno-14-112" href="#__codelineno-14-112"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="n">Pair</span><span class="w"> </span><span class="n">pair</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">buckets</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-113" name="__codelineno-14-113" href="#__codelineno-14-113"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">pair</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-114" name="__codelineno-14-114" href="#__codelineno-14-114"></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="s">&quot;null&quot;</span><span class="p">);</span>
<a id="__codelineno-14-115" name="__codelineno-14-115" href="#__codelineno-14-115"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-116" name="__codelineno-14-116" href="#__codelineno-14-116"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-117" name="__codelineno-14-117" href="#__codelineno-14-117"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-118" name="__codelineno-14-118" href="#__codelineno-14-118"></a><span class="p">}</span>
<a id="__codelineno-14-115" name="__codelineno-14-115" href="#__codelineno-14-115"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">pair</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">TOMBSTONE</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-116" name="__codelineno-14-116" href="#__codelineno-14-116"></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="s">&quot;TOMBSTONE&quot;</span><span class="p">);</span>
<a id="__codelineno-14-117" name="__codelineno-14-117" href="#__codelineno-14-117"></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-14-118" name="__codelineno-14-118" href="#__codelineno-14-118"></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="n">pair</span><span class="p">.</span><span class="na">key</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s">&quot; -&gt; &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">pair</span><span class="p">.</span><span class="na">val</span><span class="p">);</span>
<a id="__codelineno-14-119" name="__codelineno-14-119" href="#__codelineno-14-119"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-120" name="__codelineno-14-120" href="#__codelineno-14-120"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-121" name="__codelineno-14-121" href="#__codelineno-14-121"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-122" name="__codelineno-14-122" href="#__codelineno-14-122"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
@@ -6062,23 +6141,104 @@
</div>
</div>
</div>
<h3 id="2">2. &nbsp; 多次哈希<a class="headerlink" href="#2" title="Permanent link">&para;</a></h3>
<p>顾名思义,多次哈希方法是使用多个哈希函数 <span class="arithmatex">\(f_1(x)\)</span><span class="arithmatex">\(f_2(x)\)</span><span class="arithmatex">\(f_3(x)\)</span><span class="arithmatex">\(\dots\)</span> 进行探测</p>
<h3 id="2">2. &nbsp; 平方探测<a class="headerlink" href="#2" title="Permanent link">&para;</a></h3>
<p>平方探测与线性探测类似,都是开放寻址的常见策略之一。当发生冲突时,平方探测不是简单地跳过一个固定的步数,而是跳过“探测次数的平方”的步数,即 <span class="arithmatex">\(1, 4, 9, \dots\)</span> </p>
<p>平方探测通主要具有以下优势。</p>
<ul>
<li><strong>插入元素</strong>:若哈希函数 <span class="arithmatex">\(f_1(x)\)</span> 出现冲突,则尝试 <span class="arithmatex">\(f_2(x)\)</span> ,以此类推,直到找到空位后插入元素</li>
<li><strong>查找元素</strong>:在相同的哈希函数顺序下进行查找,直到找到目标元素时返回;或遇到空位或已尝试所有哈希函数,说明哈希表中不存在该元素,则返回 <span class="arithmatex">\(\text{None}\)</span> </li>
<li>平方探测通过跳过平方的距离,试图缓解线性探测的聚集效应</li>
<li>平方探测会跳过更大的距离来寻找空位置,有助于数据分布得更加均匀</li>
</ul>
<p>然而,平方探测也并不是完美的。</p>
<ul>
<li>仍然存在聚集现象,即某些位置比其他位置更容易被占用。</li>
<li>由于平方的增长,平方探测可能不会探测整个哈希表,这意味着即使哈希表中有空桶,平方探测也可能无法访问到它。</li>
</ul>
<h3 id="3">3. &nbsp; 多次哈希<a class="headerlink" href="#3" title="Permanent link">&para;</a></h3>
<p>多次哈希使用多个哈希函数 <span class="arithmatex">\(f_1(x)\)</span><span class="arithmatex">\(f_2(x)\)</span><span class="arithmatex">\(f_3(x)\)</span><span class="arithmatex">\(\dots\)</span> 进行探测。</p>
<ul>
<li><strong>插入元素</strong>:若哈希函数 <span class="arithmatex">\(f_1(x)\)</span> 出现冲突,则尝试 <span class="arithmatex">\(f_2(x)\)</span> ,以此类推,直到找到空桶后插入元素。</li>
<li><strong>查找元素</strong>:在相同的哈希函数顺序下进行查找,直到找到目标元素时返回;或当遇到空桶或已尝试所有哈希函数,说明哈希表中不存在该元素,则返回 <span class="arithmatex">\(\text{None}\)</span></li>
</ul>
<p>与线性探测相比,多次哈希方法不易产生聚集,但多个哈希函数会增加额外的计算量。</p>
<div class="admonition tip">
<p class="admonition-title">Tip</p>
<p>请注意,开放寻址(线性探测、平方探测和多次哈希)哈希表都存在“不能直接删除元素”的问题。</p>
</div>
<h2 id="623">6.2.3 &nbsp; 编程语言的选择<a class="headerlink" href="#623" title="Permanent link">&para;</a></h2>
<p>Java 采用链式地址。自 JDK 1.8 以来,当 HashMap 内数组长度达到 64 且链表长度达到 8 时,链表会被转换为红黑树以提升查找性能</p>
<p>Python 采用开放寻址。字典 dict 使用伪随机数进行探测。</p>
<p>Golang 采用链式地址。Go 规定每个桶最多存储 8 个键值对,超出容量则连接一个溢出桶;当溢出桶过多时,会执行一次特殊的等量扩容操作,以确保性能。</p>
<p>各个编程语言采取了不同的哈希表实现策略,以下举几个例子</p>
<ul>
<li>Java 采用链式地址。自 JDK 1.8 以来,当 HashMap 内数组长度达到 64 且链表长度达到 8 时,链表会被转换为红黑树以提升查找性能。</li>
<li>Python 采用开放寻址。字典 dict 使用伪随机数进行探测。</li>
<li>Golang 采用链式地址。Go 规定每个桶最多存储 8 个键值对,超出容量则连接一个溢出桶。当溢出桶过多时,会执行一次特殊的等量扩容操作,以确保性能。</li>
</ul>
<!-- Source file information -->
<!-- Was this page helpful? -->
<!-- Previous and next pages link -->
<nav
class="md-footer__inner md-grid"
aria-label="页脚"
<h2 id="__comments">评论</h2>
>
<!-- Link to previous page -->
<a
href="../hash_map/"
class="md-footer__link md-footer__link--prev"
aria-label="上一页: 6.1 &amp;nbsp; 哈希表"
rel="prev"
>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</div>
<div class="md-footer__title">
<span class="md-footer__direction">
上一页
</span>
<div class="md-ellipsis">
6.1 &nbsp; 哈希表
</div>
</div>
</a>
<!-- Link to next page -->
<a
href="../hash_algorithm/"
class="md-footer__link md-footer__link--next"
aria-label="下一页: 6.3 &amp;nbsp; 哈希算法"
rel="next"
>
<div class="md-footer__title">
<span class="md-footer__direction">
下一页
</span>
<div class="md-ellipsis">
6.3 &nbsp; 哈希算法
</div>
</div>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11H4Z"/></svg>
</div>
</a>
</nav>
<!-- Comment system -->
<h5 align="center" id="__comments">欢迎你提出疑问或建议</h5>
<!-- Insert generated snippet here -->
<script
src="https://giscus.app/client.js"
@@ -6144,48 +6304,31 @@
</main>
<footer class="md-footer">
<nav class="md-footer__inner md-grid" aria-label="页脚" >
<a href="../hash_map/" class="md-footer__link md-footer__link--prev" aria-label="上一页: 6.1 &amp;nbsp; 哈希表" rel="prev">
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</div>
<div class="md-footer__title">
<span class="md-footer__direction">
上一页
</span>
<div class="md-ellipsis">
6.1 &nbsp; 哈希表
</div>
</div>
</a>
<a href="../hash_algorithm/" class="md-footer__link md-footer__link--next" aria-label="下一页: 6.3 &amp;nbsp; 哈希算法" rel="next">
<div class="md-footer__title">
<span class="md-footer__direction">
下一页
</span>
<div class="md-ellipsis">
6.3 &nbsp; 哈希算法
</div>
</div>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11H4Z"/></svg>
</div>
</a>
</nav>
<!--
Copyright (c) 2016-2023 Martin Donath <martin.donath@squidfunk.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.
-->
<!-- Footer -->
<footer class="md-footer">
<!-- Further information -->
<div class="md-footer-meta md-typeset">
<div class="md-footer-meta__inner md-grid">
<div class="md-copyright">
@@ -6196,6 +6339,8 @@
</div>
<!-- Social links -->
<div class="md-social">
+131 -54
View File
@@ -3444,7 +3444,32 @@
<div class="md-content" data-md-component="content">
<article class="md-content__inner md-typeset">
<!--
Copyright (c) 2016-2023 Martin Donath <martin.donath@squidfunk.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.
-->
<!-- Tags -->
<!-- Actions -->
<a href="https://github.com/krahets/hello-algo/tree/main/docs/chapter_hashing/hash_map.md" title="编辑此页" class="md-content__button md-icon">
@@ -3455,6 +3480,13 @@
<!--
Hack: check whether the content contains a h1 headline. If it doesn't, the
page title (or respectively site name) is used as the main headline.
-->
<!-- Page content -->
<h1 id="61">6.1 &nbsp; 哈希表<a class="headerlink" href="#61" title="Permanent link">&para;</a></h1>
<p>「哈希表 hash table」,又称「散列表」,其通过建立键 <code>key</code> 与值 <code>value</code> 之间的映射,实现高效的元素查询。具体而言,我们向哈希表输入一个键 <code>key</code> ,则可以在 <span class="arithmatex">\(O(1)\)</span> 时间内获取对应的值 <code>value</code></p>
<p>如图 6-1 所示,给定 <span class="arithmatex">\(n\)</span> 个学生,每个学生都有“姓名”和“学号”两项数据。假如我们希望实现“输入一个学号,返回对应的姓名”的查询功能,则可以采用图 6-1 所示的哈希表来实现。</p>
@@ -4543,11 +4575,10 @@
<a id="__codelineno-31-77" name="__codelineno-31-77" href="#__codelineno-31-77"></a><span class="w"> </span><span class="nx">print</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-78" name="__codelineno-31-78" href="#__codelineno-31-78"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">pairSet</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">entries</span><span class="p">();</span>
<a id="__codelineno-31-79" name="__codelineno-31-79" href="#__codelineno-31-79"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">const</span><span class="w"> </span><span class="nx">pair</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="nx">pairSet</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-80" name="__codelineno-31-80" href="#__codelineno-31-80"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="o">!</span><span class="nx">pair</span><span class="p">)</span><span class="w"> </span><span class="k">continue</span><span class="p">;</span>
<a id="__codelineno-31-81" name="__codelineno-31-81" href="#__codelineno-31-81"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">info</span><span class="p">(</span><span class="sb">`</span><span class="si">${</span><span class="nx">pair</span><span class="p">.</span><span class="nx">key</span><span class="si">}</span><span class="sb"> -&gt; </span><span class="si">${</span><span class="nx">pair</span><span class="p">.</span><span class="nx">val</span><span class="si">}</span><span class="sb">`</span><span class="p">);</span>
<a id="__codelineno-31-82" name="__codelineno-31-82" href="#__codelineno-31-82"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-83" name="__codelineno-31-83" href="#__codelineno-31-83"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-84" name="__codelineno-31-84" href="#__codelineno-31-84"></a><span class="p">}</span>
<a id="__codelineno-31-80" name="__codelineno-31-80" href="#__codelineno-31-80"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">info</span><span class="p">(</span><span class="sb">`</span><span class="si">${</span><span class="nx">pair</span><span class="p">.</span><span class="nx">key</span><span class="si">}</span><span class="sb"> -&gt; </span><span class="si">${</span><span class="nx">pair</span><span class="p">.</span><span class="nx">val</span><span class="si">}</span><span class="sb">`</span><span class="p">);</span>
<a id="__codelineno-31-81" name="__codelineno-31-81" href="#__codelineno-31-81"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-82" name="__codelineno-31-82" href="#__codelineno-31-82"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-83" name="__codelineno-31-83" href="#__codelineno-31-83"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
@@ -4634,11 +4665,10 @@
<a id="__codelineno-32-81" name="__codelineno-32-81" href="#__codelineno-32-81"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="nx">print</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-82" name="__codelineno-32-82" href="#__codelineno-32-82"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">pairSet</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">entries</span><span class="p">();</span>
<a id="__codelineno-32-83" name="__codelineno-32-83" href="#__codelineno-32-83"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">const</span><span class="w"> </span><span class="nx">pair</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="nx">pairSet</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-84" name="__codelineno-32-84" href="#__codelineno-32-84"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="o">!</span><span class="nx">pair</span><span class="p">)</span><span class="w"> </span><span class="k">continue</span><span class="p">;</span>
<a id="__codelineno-32-85" name="__codelineno-32-85" href="#__codelineno-32-85"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">info</span><span class="p">(</span><span class="sb">`</span><span class="si">${</span><span class="nx">pair</span><span class="p">.</span><span class="nx">key</span><span class="si">}</span><span class="sb"> -&gt; </span><span class="si">${</span><span class="nx">pair</span><span class="p">.</span><span class="nx">val</span><span class="si">}</span><span class="sb">`</span><span class="p">);</span>
<a id="__codelineno-32-86" name="__codelineno-32-86" href="#__codelineno-32-86"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-87" name="__codelineno-32-87" href="#__codelineno-32-87"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-88" name="__codelineno-32-88" href="#__codelineno-32-88"></a><span class="p">}</span>
<a id="__codelineno-32-84" name="__codelineno-32-84" href="#__codelineno-32-84"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">info</span><span class="p">(</span><span class="sb">`</span><span class="si">${</span><span class="nx">pair</span><span class="p">.</span><span class="nx">key</span><span class="si">}</span><span class="sb"> -&gt; </span><span class="si">${</span><span class="nx">pair</span><span class="p">.</span><span class="nx">val</span><span class="si">}</span><span class="sb">`</span><span class="p">);</span>
<a id="__codelineno-32-85" name="__codelineno-32-85" href="#__codelineno-32-85"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-86" name="__codelineno-32-86" href="#__codelineno-32-86"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-87" name="__codelineno-32-87" href="#__codelineno-32-87"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
@@ -4937,11 +4967,73 @@
<p>类似于数组扩容,哈希表扩容需将所有键值对从原哈希表迁移至新哈希表,非常耗时。并且由于哈希表容量 <code>capacity</code> 改变,我们需要通过哈希函数来重新计算所有键值对的存储位置,这进一步提高了扩容过程的计算开销。为此,编程语言通常会预留足够大的哈希表容量,防止频繁扩容。</p>
<p>「负载因子 load factor」是哈希表的一个重要概念,其定义为哈希表的元素数量除以桶数量,用于衡量哈希冲突的严重程度,<strong>也常被作为哈希表扩容的触发条件</strong>。例如在 Java 中,当负载因子超过 <span class="arithmatex">\(0.75\)</span> 时,系统会将哈希表容量扩展为原先的 <span class="arithmatex">\(2\)</span> 倍。</p>
<!-- Source file information -->
<!-- Was this page helpful? -->
<h2 id="__comments">评论</h2>
<!-- Previous and next pages link -->
<nav
class="md-footer__inner md-grid"
aria-label="页脚"
>
<!-- Link to previous page -->
<a
href="../"
class="md-footer__link md-footer__link--prev"
aria-label="上一页: 第 6 章 &amp;nbsp; 哈希表"
rel="prev"
>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</div>
<div class="md-footer__title">
<span class="md-footer__direction">
上一页
</span>
<div class="md-ellipsis">
第 6 章 &nbsp; 哈希表
</div>
</div>
</a>
<!-- Link to next page -->
<a
href="../hash_collision/"
class="md-footer__link md-footer__link--next"
aria-label="下一页: 6.2 &amp;nbsp; 哈希冲突"
rel="next"
>
<div class="md-footer__title">
<span class="md-footer__direction">
下一页
</span>
<div class="md-ellipsis">
6.2 &nbsp; 哈希冲突
</div>
</div>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11H4Z"/></svg>
</div>
</a>
</nav>
<!-- Comment system -->
<h5 align="center" id="__comments">欢迎你提出疑问或建议</h5>
<!-- Insert generated snippet here -->
<script
src="https://giscus.app/client.js"
@@ -5007,48 +5099,31 @@
</main>
<footer class="md-footer">
<nav class="md-footer__inner md-grid" aria-label="页脚" >
<a href="../" class="md-footer__link md-footer__link--prev" aria-label="上一页: 第 6 章 &amp;nbsp; 哈希表" rel="prev">
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</div>
<div class="md-footer__title">
<span class="md-footer__direction">
上一页
</span>
<div class="md-ellipsis">
第 6 章 &nbsp; 哈希表
</div>
</div>
</a>
<a href="../hash_collision/" class="md-footer__link md-footer__link--next" aria-label="下一页: 6.2 &amp;nbsp; 哈希冲突" rel="next">
<div class="md-footer__title">
<span class="md-footer__direction">
下一页
</span>
<div class="md-ellipsis">
6.2 &nbsp; 哈希冲突
</div>
</div>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11H4Z"/></svg>
</div>
</a>
</nav>
<!--
Copyright (c) 2016-2023 Martin Donath <martin.donath@squidfunk.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.
-->
<!-- Footer -->
<footer class="md-footer">
<!-- Further information -->
<div class="md-footer-meta md-typeset">
<div class="md-footer-meta__inner md-grid">
<div class="md-copyright">
@@ -5059,6 +5134,8 @@
</div>
<!-- Social links -->
<div class="md-social">
+123 -44
View File
@@ -3369,7 +3369,32 @@
<div class="md-content" data-md-component="content">
<article class="md-content__inner md-typeset">
<!--
Copyright (c) 2016-2023 Martin Donath <martin.donath@squidfunk.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.
-->
<!-- Tags -->
<!-- Actions -->
<a href="https://github.com/krahets/hello-algo/tree/main/docs/chapter_hashing/index.md" title="编辑此页" class="md-content__button md-icon">
@@ -3380,6 +3405,13 @@
<!--
Hack: check whether the content contains a h1 headline. If it doesn't, the
page title (or respectively site name) is used as the main headline.
-->
<!-- Page content -->
<h1 id="6">第 6 章 &nbsp; 哈希表<a class="headerlink" href="#6" title="Permanent link">&para;</a></h1>
<div class="center-table">
<p><img alt="哈希表" src="../assets/covers/chapter_hashing.jpg" width="600" /></p>
@@ -3397,11 +3429,73 @@
<li><a href="https://www.hello-algo.com/chapter_hashing/summary/">6.4 &nbsp; 小结</a></li>
</ul>
<!-- Source file information -->
<!-- Was this page helpful? -->
<h2 id="__comments">评论</h2>
<!-- Previous and next pages link -->
<nav
class="md-footer__inner md-grid"
aria-label="页脚"
>
<!-- Link to previous page -->
<a
href="../chapter_stack_and_queue/summary/"
class="md-footer__link md-footer__link--prev"
aria-label="上一页: 5.4 &amp;nbsp; 小结"
rel="prev"
>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</div>
<div class="md-footer__title">
<span class="md-footer__direction">
上一页
</span>
<div class="md-ellipsis">
5.4 &nbsp; 小结
</div>
</div>
</a>
<!-- Link to next page -->
<a
href="hash_map/"
class="md-footer__link md-footer__link--next"
aria-label="下一页: 6.1 &amp;nbsp; 哈希表"
rel="next"
>
<div class="md-footer__title">
<span class="md-footer__direction">
下一页
</span>
<div class="md-ellipsis">
6.1 &nbsp; 哈希表
</div>
</div>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11H4Z"/></svg>
</div>
</a>
</nav>
<!-- Comment system -->
<h5 align="center" id="__comments">欢迎你提出疑问或建议</h5>
<!-- Insert generated snippet here -->
<script
src="https://giscus.app/client.js"
@@ -3467,48 +3561,31 @@
</main>
<footer class="md-footer">
<nav class="md-footer__inner md-grid" aria-label="页脚" >
<a href="../chapter_stack_and_queue/summary/" class="md-footer__link md-footer__link--prev" aria-label="上一页: 5.4 &amp;nbsp; 小结" rel="prev">
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</div>
<div class="md-footer__title">
<span class="md-footer__direction">
上一页
</span>
<div class="md-ellipsis">
5.4 &nbsp; 小结
</div>
</div>
</a>
<a href="hash_map/" class="md-footer__link md-footer__link--next" aria-label="下一页: 6.1 &amp;nbsp; 哈希表" rel="next">
<div class="md-footer__title">
<span class="md-footer__direction">
下一页
</span>
<div class="md-ellipsis">
6.1 &nbsp; 哈希表
</div>
</div>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11H4Z"/></svg>
</div>
</a>
</nav>
<!--
Copyright (c) 2016-2023 Martin Donath <martin.donath@squidfunk.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.
-->
<!-- Footer -->
<footer class="md-footer">
<!-- Further information -->
<div class="md-footer-meta md-typeset">
<div class="md-footer-meta__inner md-grid">
<div class="md-copyright">
@@ -3519,6 +3596,8 @@
</div>
<!-- Social links -->
<div class="md-social">
+123 -44
View File
@@ -3430,7 +3430,32 @@
<div class="md-content" data-md-component="content">
<article class="md-content__inner md-typeset">
<!--
Copyright (c) 2016-2023 Martin Donath <martin.donath@squidfunk.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.
-->
<!-- Tags -->
<!-- Actions -->
<a href="https://github.com/krahets/hello-algo/tree/main/docs/chapter_hashing/summary.md" title="编辑此页" class="md-content__button md-icon">
@@ -3441,6 +3466,13 @@
<!--
Hack: check whether the content contains a h1 headline. If it doesn't, the
page title (or respectively site name) is used as the main headline.
-->
<!-- Page content -->
<h1 id="64">6.4 &nbsp; 小结<a class="headerlink" href="#64" title="Permanent link">&para;</a></h1>
<h3 id="1">1. &nbsp; 重点回顾<a class="headerlink" href="#1" title="Permanent link">&para;</a></h3>
<ul>
@@ -3486,11 +3518,73 @@
<p>哈希函数的最后一步往往是对数组长度 <span class="arithmatex">\(n\)</span> 取余,让输出值落入在数组索引范围;在扩容后,数组长度 <span class="arithmatex">\(n\)</span> 发生变化,而 <code>key</code> 对应的索引也可能发生变化。原先落在同一个桶的多个 <code>key</code> ,在扩容后可能会被分配到多个桶中,从而实现哈希冲突的缓解。</p>
</div>
<!-- Source file information -->
<!-- Was this page helpful? -->
<h2 id="__comments">评论</h2>
<!-- Previous and next pages link -->
<nav
class="md-footer__inner md-grid"
aria-label="页脚"
>
<!-- Link to previous page -->
<a
href="../hash_algorithm/"
class="md-footer__link md-footer__link--prev"
aria-label="上一页: 6.3 &amp;nbsp; 哈希算法"
rel="prev"
>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</div>
<div class="md-footer__title">
<span class="md-footer__direction">
上一页
</span>
<div class="md-ellipsis">
6.3 &nbsp; 哈希算法
</div>
</div>
</a>
<!-- Link to next page -->
<a
href="../../chapter_tree/"
class="md-footer__link md-footer__link--next"
aria-label="下一页: 第 7 章 &amp;nbsp; 树"
rel="next"
>
<div class="md-footer__title">
<span class="md-footer__direction">
下一页
</span>
<div class="md-ellipsis">
第 7 章 &nbsp;
</div>
</div>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11H4Z"/></svg>
</div>
</a>
</nav>
<!-- Comment system -->
<h5 align="center" id="__comments">欢迎你提出疑问或建议</h5>
<!-- Insert generated snippet here -->
<script
src="https://giscus.app/client.js"
@@ -3556,48 +3650,31 @@
</main>
<footer class="md-footer">
<nav class="md-footer__inner md-grid" aria-label="页脚" >
<a href="../hash_algorithm/" class="md-footer__link md-footer__link--prev" aria-label="上一页: 6.3 &amp;nbsp; 哈希算法" rel="prev">
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</div>
<div class="md-footer__title">
<span class="md-footer__direction">
上一页
</span>
<div class="md-ellipsis">
6.3 &nbsp; 哈希算法
</div>
</div>
</a>
<a href="../../chapter_tree/" class="md-footer__link md-footer__link--next" aria-label="下一页: 第 7 章 &amp;nbsp; 树" rel="next">
<div class="md-footer__title">
<span class="md-footer__direction">
下一页
</span>
<div class="md-ellipsis">
第 7 章 &nbsp;
</div>
</div>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11H4Z"/></svg>
</div>
</a>
</nav>
<!--
Copyright (c) 2016-2023 Martin Donath <martin.donath@squidfunk.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.
-->
<!-- Footer -->
<footer class="md-footer">
<!-- Further information -->
<div class="md-footer-meta md-typeset">
<div class="md-footer-meta__inner md-grid">
<div class="md-copyright">
@@ -3608,6 +3685,8 @@
</div>
<!-- Social links -->
<div class="md-social">