<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>4.8 练习：Collatz 序列 on 编程那些事儿</title><link>https://before80.github.io/prgms/Rust/comprehensiveRust/day1-morning/control-flow-basics/exercise/</link><description>Recent content in 4.8 练习：Collatz 序列 on 编程那些事儿</description><generator>Hugo</generator><language>zh-cn</language><lastBuildDate>Tue, 11 Aug 2026 23:57:44 +0800</lastBuildDate><atom:link href="https://before80.github.io/prgms/Rust/comprehensiveRust/day1-morning/control-flow-basics/exercise/index.xml" rel="self" type="application/rss+xml"/><item><title>4.8.1 解答</title><link>https://before80.github.io/prgms/Rust/comprehensiveRust/day1-morning/control-flow-basics/exercise/01-solution/</link><pubDate>Tue, 11 Aug 2026 11:30:00 +0800</pubDate><guid>https://before80.github.io/prgms/Rust/comprehensiveRust/day1-morning/control-flow-basics/exercise/01-solution/</guid><description>&lt;blockquote&gt;
&lt;p&gt;译文 · 基于 &lt;a href="https://google.github.io/comprehensive-rust/"&gt;Comprehensive Rust&lt;/a&gt;&lt;/p&gt;
&lt;/blockquote&gt;
&lt;blockquote&gt;
&lt;p&gt;原文链接: &lt;a href="https://google.github.io/comprehensive-rust/control-flow-basics/solution.html"&gt;https://google.github.io/comprehensive-rust/control-flow-basics/solution.html&lt;/a&gt;&lt;/p&gt;
&lt;/blockquote&gt;
&lt;h1 id="481-解答"&gt;4.8.1 解答&lt;/h1&gt;
&lt;div class="highlight"&gt;&lt;div style="color:#b0c4de;background-color:#282c34;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;
&lt;table style="border-spacing:0;padding:0;margin:0;border:0;"&gt;&lt;tr&gt;&lt;td style="vertical-align:top;padding:0;margin:0;border:0;"&gt;
&lt;pre tabindex="0" style="color:#b0c4de;background-color:#282c34;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt; 1
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt; 2
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt; 3
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt; 4
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt; 5
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt; 6
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt; 7
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt; 8
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt; 9
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt;10
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt;11
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt;12
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt;13
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt;14
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt;15
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/td&gt;
&lt;td style="vertical-align:top;padding:0;margin:0;border:0;;width:100%"&gt;
&lt;pre tabindex="0" style="color:#b0c4de;background-color:#282c34;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-rust" data-lang="rust"&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#8a93a5;font-style:italic"&gt;// Copyright 2023 Google LLC
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#8a93a5;font-style:italic"&gt;// SPDX-License-Identifier: Apache-2.0
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#7e97c3"&gt;/// 计算从 `n` 开始的 Collatz 序列长度。
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#76a9f9"&gt;fn&lt;/span&gt; &lt;span style="color:#00b1f7"&gt;collatz_length&lt;/span&gt;&lt;span style="color:#abb2bf"&gt;(&lt;/span&gt;&lt;span style="color:#76a9f9"&gt;mut&lt;/span&gt; &lt;span style="color:#aa89ea"&gt;n&lt;/span&gt;: &lt;span style="color:#e5c07b"&gt;i32&lt;/span&gt;&lt;span style="color:#abb2bf"&gt;)&lt;/span&gt; -&amp;gt; &lt;span style="color:#e5c07b"&gt;u32&lt;/span&gt; &lt;span style="color:#abb2bf"&gt;{&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#76a9f9"&gt;let&lt;/span&gt; &lt;span style="color:#76a9f9"&gt;mut&lt;/span&gt; &lt;span style="color:#aa89ea"&gt;len&lt;/span&gt; &lt;span style="color:#54b1c7"&gt;=&lt;/span&gt; &lt;span style="color:#d19a66"&gt;1&lt;/span&gt;&lt;span style="color:#abb2bf"&gt;;&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#76a9f9"&gt;while&lt;/span&gt; &lt;span style="color:#aa89ea"&gt;n&lt;/span&gt; &lt;span style="color:#54b1c7"&gt;&amp;gt;&lt;/span&gt; &lt;span style="color:#d19a66"&gt;1&lt;/span&gt; &lt;span style="color:#abb2bf"&gt;{&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#aa89ea"&gt;n&lt;/span&gt; &lt;span style="color:#54b1c7"&gt;=&lt;/span&gt; &lt;span style="color:#76a9f9"&gt;if&lt;/span&gt; &lt;span style="color:#aa89ea"&gt;n&lt;/span&gt; &lt;span style="color:#54b1c7"&gt;%&lt;/span&gt; &lt;span style="color:#d19a66"&gt;2&lt;/span&gt; &lt;span style="color:#54b1c7"&gt;==&lt;/span&gt; &lt;span style="color:#d19a66"&gt;0&lt;/span&gt; &lt;span style="color:#abb2bf"&gt;{&lt;/span&gt; &lt;span style="color:#aa89ea"&gt;n&lt;/span&gt; &lt;span style="color:#54b1c7"&gt;/&lt;/span&gt; &lt;span style="color:#d19a66"&gt;2&lt;/span&gt; &lt;span style="color:#abb2bf"&gt;}&lt;/span&gt; &lt;span style="color:#76a9f9"&gt;else&lt;/span&gt; &lt;span style="color:#abb2bf"&gt;{&lt;/span&gt; &lt;span style="color:#d19a66"&gt;3&lt;/span&gt; &lt;span style="color:#54b1c7"&gt;*&lt;/span&gt; &lt;span style="color:#aa89ea"&gt;n&lt;/span&gt; &lt;span style="color:#54b1c7"&gt;+&lt;/span&gt; &lt;span style="color:#d19a66"&gt;1&lt;/span&gt; &lt;span style="color:#abb2bf"&gt;};&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#aa89ea"&gt;len&lt;/span&gt; &lt;span style="color:#54b1c7"&gt;+=&lt;/span&gt; &lt;span style="color:#d19a66"&gt;1&lt;/span&gt;&lt;span style="color:#abb2bf"&gt;;&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#abb2bf"&gt;}&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#aa89ea"&gt;len&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#abb2bf"&gt;}&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#76a9f9"&gt;fn&lt;/span&gt; &lt;span style="color:#00b1f7"&gt;main&lt;/span&gt;&lt;span style="color:#abb2bf"&gt;()&lt;/span&gt; &lt;span style="color:#abb2bf"&gt;{&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#00b1f7"&gt;println!&lt;/span&gt;&lt;span style="color:#abb2bf"&gt;(&lt;/span&gt;&lt;span style="color:#98c379"&gt;&amp;#34;Length: &lt;/span&gt;&lt;span style="color:#98c379"&gt;{}&lt;/span&gt;&lt;span style="color:#98c379"&gt;&amp;#34;&lt;/span&gt;&lt;span style="color:#abb2bf"&gt;,&lt;/span&gt; &lt;span style="color:#aa89ea"&gt;collatz_length&lt;/span&gt;&lt;span style="color:#abb2bf"&gt;(&lt;/span&gt;&lt;span style="color:#d19a66"&gt;11&lt;/span&gt;&lt;span style="color:#abb2bf"&gt;));&lt;/span&gt; &lt;span style="color:#8a93a5;font-style:italic"&gt;// 应为 15
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#abb2bf"&gt;}&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;
&lt;/div&gt;
&lt;/div&gt;&lt;p&gt;该解答展示了几个关键的 Rust 特性：&lt;/p&gt;</description></item></channel></rss>