This commit is contained in:
krahets
2024-04-11 01:11:27 +08:00
parent a4dec11e8e
commit ba0bcfa7a9
94 changed files with 2561 additions and 1998 deletions
@@ -3730,7 +3730,8 @@
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><pre><span></span><code><a id="__codelineno-12-1" name="__codelineno-12-1" href="#__codelineno-12-1"></a>
<div class="highlight"><pre><span></span><code><a id="__codelineno-12-1" name="__codelineno-12-1" href="#__codelineno-12-1"></a><span class="c1"># Ruby 的串列可以自由儲存各種基本資料型別和物件引用</span>
<a id="__codelineno-12-2" name="__codelineno-12-2" href="#__codelineno-12-2"></a><span class="n">data</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="o">[</span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="mi">0</span><span class="o">.</span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="s1">&#39;a&#39;</span><span class="p">,</span><span class="w"> </span><span class="kp">false</span><span class="p">,</span><span class="w"> </span><span class="no">ListNode</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span><span class="o">]</span>
</code></pre></div>
</div>
<div class="tabbed-block">
@@ -3741,8 +3742,8 @@
</div>
<details class="pythontutor">
<summary>視覺化執行</summary>
<p><div style="height: 477px; width: 100%;"><iframe class="pythontutor-iframe" src="https://pythontutor.com/iframe-embed.html#code=class%20ListNode%3A%0A%20%20%20%20%22%22%22%E9%93%BE%E8%A1%A8%E8%8A%82%E7%82%B9%E7%B1%BB%22%22%22%0A%20%20%20%20def%20__init__%28self,%20val%3A%20int%29%3A%0A%20%20%20%20%20%20%20%20self.val%3A%20int%20%3D%20val%20%20%23%20%E8%8A%82%E7%82%B9%E5%80%BC%0A%20%20%20%20%20%20%20%20self.next%3A%20ListNode%20%7C%20None%20%3D%20None%20%20%23%20%E5%90%8E%E7%BB%A7%E8%8A%82%E7%82%B9%E5%BC%95%E7%94%A8%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20%23%20%E4%BD%BF%E7%94%A8%E5%A4%9A%E7%A7%8D%E5%9F%BA%E6%9C%AC%E6%95%B0%E6%8D%AE%E7%B1%BB%E5%9E%8B%E6%9D%A5%E5%88%9D%E5%A7%8B%E5%8C%96%E6%95%B0%E7%BB%84%0A%20%20%20%20numbers%20%3D%20%5B0%5D%20*%205%0A%20%20%20%20decimals%20%3D%20%5B0.0%5D%20*%205%0A%20%20%20%20%23%20Python%20%E7%9A%84%E5%AD%97%E7%AC%A6%E5%AE%9E%E9%99%85%E4%B8%8A%E6%98%AF%E9%95%BF%E5%BA%A6%E4%B8%BA%201%20%E7%9A%84%E5%AD%97%E7%AC%A6%E4%B8%B2%0A%20%20%20%20characters%20%3D%20%5B'0'%5D%20*%205%0A%20%20%20%20bools%20%3D%20%5BFalse%5D%20*%205%0A%20%20%20%20%23%20Python%20%E7%9A%84%E5%88%97%E8%A1%A8%E5%8F%AF%E4%BB%A5%E8%87%AA%E7%94%B1%E5%AD%98%E5%82%A8%E5%90%84%E7%A7%8D%E5%9F%BA%E6%9C%AC%E6%95%B0%E6%8D%AE%E7%B1%BB%E5%9E%8B%E5%92%8C%E5%AF%B9%E8%B1%A1%E5%BC%95%E7%94%A8%0A%20%20%20%20data%20%3D%20%5B0,%200.0,%20'a',%20False,%20ListNode%280%29%5D&codeDivHeight=472&codeDivWidth=350&cumulative=false&curInstr=12&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false"> </iframe></div>
<div style="margin-top: 5px;"><a href="https://pythontutor.com/iframe-embed.html#code=class%20ListNode%3A%0A%20%20%20%20%22%22%22%E9%93%BE%E8%A1%A8%E8%8A%82%E7%82%B9%E7%B1%BB%22%22%22%0A%20%20%20%20def%20__init__%28self,%20val%3A%20int%29%3A%0A%20%20%20%20%20%20%20%20self.val%3A%20int%20%3D%20val%20%20%23%20%E8%8A%82%E7%82%B9%E5%80%BC%0A%20%20%20%20%20%20%20%20self.next%3A%20ListNode%20%7C%20None%20%3D%20None%20%20%23%20%E5%90%8E%E7%BB%A7%E8%8A%82%E7%82%B9%E5%BC%95%E7%94%A8%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20%23%20%E4%BD%BF%E7%94%A8%E5%A4%9A%E7%A7%8D%E5%9F%BA%E6%9C%AC%E6%95%B0%E6%8D%AE%E7%B1%BB%E5%9E%8B%E6%9D%A5%E5%88%9D%E5%A7%8B%E5%8C%96%E6%95%B0%E7%BB%84%0A%20%20%20%20numbers%20%3D%20%5B0%5D%20*%205%0A%20%20%20%20decimals%20%3D%20%5B0.0%5D%20*%205%0A%20%20%20%20%23%20Python%20%E7%9A%84%E5%AD%97%E7%AC%A6%E5%AE%9E%E9%99%85%E4%B8%8A%E6%98%AF%E9%95%BF%E5%BA%A6%E4%B8%BA%201%20%E7%9A%84%E5%AD%97%E7%AC%A6%E4%B8%B2%0A%20%20%20%20characters%20%3D%20%5B'0'%5D%20*%205%0A%20%20%20%20bools%20%3D%20%5BFalse%5D%20*%205%0A%20%20%20%20%23%20Python%20%E7%9A%84%E5%88%97%E8%A1%A8%E5%8F%AF%E4%BB%A5%E8%87%AA%E7%94%B1%E5%AD%98%E5%82%A8%E5%90%84%E7%A7%8D%E5%9F%BA%E6%9C%AC%E6%95%B0%E6%8D%AE%E7%B1%BB%E5%9E%8B%E5%92%8C%E5%AF%B9%E8%B1%A1%E5%BC%95%E7%94%A8%0A%20%20%20%20data%20%3D%20%5B0,%200.0,%20'a',%20False,%20ListNode%280%29%5D&codeDivHeight=800&codeDivWidth=600&cumulative=false&curInstr=12&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false" target="_blank" rel="noopener noreferrer">全螢幕觀看 &gt;</a></div></p>
<p><div style="height: 477px; width: 100%;"><iframe class="pythontutor-iframe" src="https://pythontutor.com/iframe-embed.html#code=class%20ListNode%3A%0A%20%20%20%20%22%22%22%E9%8F%88%E7%B5%90%E4%B8%B2%E5%88%97%E7%AF%80%E9%BB%9E%E9%A1%9E%E5%88%A5%22%22%22%0A%20%20%20%20def%20__init__%28self%2C%20val%3A%20int%29%3A%0A%20%20%20%20%20%20%20%20self.val%3A%20int%20%3D%20val%20%20%23%20%E7%AF%80%E9%BB%9E%E5%80%BC%0A%20%20%20%20%20%20%20%20self.next%3A%20ListNode%20%7C%20None%20%3D%20None%20%20%23%20%E5%BE%8C%E7%B9%BC%E7%AF%80%E9%BB%9E%E5%BC%95%E7%94%A8%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20%23%20%E4%BD%BF%E7%94%A8%E5%A4%9A%E7%A8%AE%E5%9F%BA%E6%9C%AC%E8%B3%87%E6%96%99%E5%9E%8B%E5%88%A5%E4%BE%86%E5%88%9D%E5%A7%8B%E5%8C%96%E9%99%A3%E5%88%97%0A%20%20%20%20numbers%20%3D%20%5B0%5D%20%2A%205%0A%20%20%20%20decimals%20%3D%20%5B0.0%5D%20%2A%205%0A%20%20%20%20%23%20Python%20%E7%9A%84%E5%AD%97%E5%85%83%E5%AF%A6%E9%9A%9B%E4%B8%8A%E6%98%AF%E9%95%B7%E5%BA%A6%E7%82%BA%201%20%E7%9A%84%E5%AD%97%E4%B8%B2%0A%20%20%20%20characters%20%3D%20%5B%270%27%5D%20%2A%205%0A%20%20%20%20bools%20%3D%20%5BFalse%5D%20%2A%205%0A%20%20%20%20%23%20Python%20%E7%9A%84%E4%B8%B2%E5%88%97%E5%8F%AF%E4%BB%A5%E8%87%AA%E7%94%B1%E5%84%B2%E5%AD%98%E5%90%84%E7%A8%AE%E5%9F%BA%E6%9C%AC%E8%B3%87%E6%96%99%E5%9E%8B%E5%88%A5%E5%92%8C%E7%89%A9%E4%BB%B6%E5%BC%95%E7%94%A8%0A%20%20%20%20data%20%3D%20%5B0%2C%200.0%2C%20%27a%27%2C%20False%2C%20ListNode%280%29%5D&codeDivHeight=472&codeDivWidth=350&cumulative=false&curInstr=12&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false"> </iframe></div>
<div style="margin-top: 5px;"><a href="https://pythontutor.com/iframe-embed.html#code=class%20ListNode%3A%0A%20%20%20%20%22%22%22%E9%8F%88%E7%B5%90%E4%B8%B2%E5%88%97%E7%AF%80%E9%BB%9E%E9%A1%9E%E5%88%A5%22%22%22%0A%20%20%20%20def%20__init__%28self%2C%20val%3A%20int%29%3A%0A%20%20%20%20%20%20%20%20self.val%3A%20int%20%3D%20val%20%20%23%20%E7%AF%80%E9%BB%9E%E5%80%BC%0A%20%20%20%20%20%20%20%20self.next%3A%20ListNode%20%7C%20None%20%3D%20None%20%20%23%20%E5%BE%8C%E7%B9%BC%E7%AF%80%E9%BB%9E%E5%BC%95%E7%94%A8%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20%23%20%E4%BD%BF%E7%94%A8%E5%A4%9A%E7%A8%AE%E5%9F%BA%E6%9C%AC%E8%B3%87%E6%96%99%E5%9E%8B%E5%88%A5%E4%BE%86%E5%88%9D%E5%A7%8B%E5%8C%96%E9%99%A3%E5%88%97%0A%20%20%20%20numbers%20%3D%20%5B0%5D%20%2A%205%0A%20%20%20%20decimals%20%3D%20%5B0.0%5D%20%2A%205%0A%20%20%20%20%23%20Python%20%E7%9A%84%E5%AD%97%E5%85%83%E5%AF%A6%E9%9A%9B%E4%B8%8A%E6%98%AF%E9%95%B7%E5%BA%A6%E7%82%BA%201%20%E7%9A%84%E5%AD%97%E4%B8%B2%0A%20%20%20%20characters%20%3D%20%5B%270%27%5D%20%2A%205%0A%20%20%20%20bools%20%3D%20%5BFalse%5D%20%2A%205%0A%20%20%20%20%23%20Python%20%E7%9A%84%E4%B8%B2%E5%88%97%E5%8F%AF%E4%BB%A5%E8%87%AA%E7%94%B1%E5%84%B2%E5%AD%98%E5%90%84%E7%A8%AE%E5%9F%BA%E6%9C%AC%E8%B3%87%E6%96%99%E5%9E%8B%E5%88%A5%E5%92%8C%E7%89%A9%E4%BB%B6%E5%BC%95%E7%94%A8%0A%20%20%20%20data%20%3D%20%5B0%2C%200.0%2C%20%27a%27%2C%20False%2C%20ListNode%280%29%5D&codeDivHeight=800&codeDivWidth=600&cumulative=false&curInstr=12&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false" target="_blank" rel="noopener noreferrer">全螢幕觀看 &gt;</a></div></p>
</details>
<!-- Source file information -->
@@ -3703,7 +3703,7 @@ b_{31} b_{30} b_{29} \ldots b_2 b_1 b_0
\]</div>
<p>現在我們可以回答最初的問題:<strong><code>float</code> 的表示方式包含指數位,導致其取值範圍遠大於 <code>int</code></strong> 。根據以上計算,<code>float</code> 可表示的最大正數為 <span class="arithmatex">\(2^{254 - 127} \times (2 - 2^{-23}) \approx 3.4 \times 10^{38}\)</span> ,切換符號位便可得到最小負數。</p>
<p><strong>儘管浮點數 <code>float</code> 擴展了取值範圍,但其副作用是犧牲了精度</strong>。整數型別 <code>int</code> 將全部 32 位元用於表示數字,數字是均勻分佈的;而由於指數位的存在,浮點數 <code>float</code> 的數值越大,相鄰兩個數字之間的差值就會趨向越大。</p>
<p>如表 3-2 所示,指數位 <span class="arithmatex">\(E = 0\)</span><span class="arithmatex">\(E = 255\)</span> 具有特殊含義,<strong>用於表示零、無窮大、<span class="arithmatex">\(\mathrm{NaN}\)</span></strong></p>
<p>如表 3-2 所示,指數位 <span class="arithmatex">\(\mathrm{E} = 0\)</span><span class="arithmatex">\(\mathrm{E} = 255\)</span> 具有特殊含義,<strong>用於表示零、無窮大、<span class="arithmatex">\(\mathrm{NaN}\)</span></strong></p>
<p align="center"> 表 3-2 &nbsp; 指數位含義 </p>
<div class="center-table">
@@ -3622,6 +3622,25 @@
<p>堆疊確實可以實現動態的資料操作,但資料結構仍然是“靜態”(長度不可變)的。儘管基於陣列的資料結構可以動態地新增或刪除元素,但它們的容量是固定的。如果資料量超出了預分配的大小,就需要建立一個新的更大的陣列,並將舊陣列的內容複製到新陣列中。</p>
<p><strong>Q</strong>:在構建堆疊(佇列)的時候,未指定它的大小,為什麼它們是“靜態資料結構”呢?</p>
<p>在高階程式語言中,我們無須人工指定堆疊(佇列)的初始容量,這個工作由類別內部自動完成。例如,Java 的 <code>ArrayList</code> 的初始容量通常為 10。另外,擴容操作也是自動實現的。詳見後續的“串列”章節。</p>
<p><strong>Q</strong>:原碼轉二補數的方法是“先取反後加 1”,那麼二補數轉原碼應該是逆運算“先減 1 後取反”,而二補數轉原碼也一樣可以透過“先取反後加 1”得到,這是為什麼呢?</p>
<p><strong>A</strong>:這是因為原碼和二補數的相互轉換實際上是計算“補數”的過程。我們先給出補數的定義:假設 <span class="arithmatex">\(a + b = c\)</span> ,那麼我們稱 <span class="arithmatex">\(a\)</span><span class="arithmatex">\(b\)</span><span class="arithmatex">\(c\)</span> 的補數,反之也稱 <span class="arithmatex">\(b\)</span><span class="arithmatex">\(a\)</span><span class="arithmatex">\(c\)</span> 的補數。</p>
<p>給定一個 <span class="arithmatex">\(n = 4\)</span> 位長度的二進位制數 <span class="arithmatex">\(0010\)</span> ,如果將這個數字看作原碼(不考慮符號位),那麼它的二補數需透過“先取反後加 1”得到:</p>
<div class="arithmatex">\[
0010 \rightarrow 1101 \rightarrow 1110
\]</div>
<p>我們會發現,原碼和二補數的和是 <span class="arithmatex">\(0010 + 1110 = 10000\)</span> ,也就是說,二補數 <span class="arithmatex">\(1110\)</span> 是原碼 <span class="arithmatex">\(0010\)</span><span class="arithmatex">\(10000\)</span> 的“補數”。<strong>這意味著上述“先取反後加 1”實際上是計算到 <span class="arithmatex">\(10000\)</span> 的補數的過程</strong></p>
<p>那麼,二補數 <span class="arithmatex">\(1110\)</span><span class="arithmatex">\(10000\)</span> 的“補數”是多少呢?我們依然可以用“先取反後加 1”得到它:</p>
<div class="arithmatex">\[
1110 \rightarrow 0001 \rightarrow 0010
\]</div>
<p>換句話說,原碼和二補數互為對方到 <span class="arithmatex">\(10000\)</span> 的“補數”,因此“原碼轉二補數”和“二補數轉原碼”可以用相同的操作(先取反後加 1 )實現。</p>
<p>當然,我們也可以用逆運算來求二補數 <span class="arithmatex">\(1110\)</span> 的原碼,即“先減 1 後取反”:</p>
<div class="arithmatex">\[
1110 \rightarrow 1101 \rightarrow 0010
\]</div>
<p>總結來看,“先取反後加 1”和“先減 1 後取反”這兩種運算都是在計算到 <span class="arithmatex">\(10000\)</span> 的補數,它們是等價的。</p>
<p>本質上看,“取反”操作實際上是求到 <span class="arithmatex">\(1111\)</span> 的補數(因為恆有 <code>原碼 + 一補數 = 1111</code>);而在一補數基礎上再加 1 得到的二補數,就是到 <span class="arithmatex">\(10000\)</span> 的補數。</p>
<p>上述 <span class="arithmatex">\(n = 4\)</span> 為例,其可推廣至任意位數的二進位制數。</p>
<!-- Source file information -->