1
0
mirror of https://gitee.com/coder-xiaomo/leetcode-problemset synced 2025-01-11 19:18:14 +08:00
Code Issues Projects Releases Wiki Activity GitHub Gitee
leetcode-problemset/leetcode-cn/problem (Chinese)/单词接龙 II [word-ladder-ii].html

48 lines
2.4 KiB
HTML
Raw Normal View History

2022-03-27 20:56:26 +08:00
<p>按字典&nbsp;<code>wordList</code> 完成从单词 <code>beginWord</code> 到单词 <code>endWord</code> 转化,一个表示此过程的 <strong>转换序列</strong> 是形式上像 <code>beginWord -&gt; s<sub>1</sub> -&gt; s<sub>2</sub> -&gt; ... -&gt; s<sub>k</sub></code> 这样的单词序列,并满足:</p>
<div class="original__bRMd">
<div>
<ul>
<li>每对相邻的单词之间仅有单个字母不同。</li>
<li>转换过程中的每个单词 <code>s<sub>i</sub></code><code>1 &lt;= i &lt;= k</code>)必须是字典&nbsp;<code>wordList</code> 中的单词。注意,<code>beginWord</code> 不必是字典 <code>wordList</code> 中的单词。</li>
<li><code>s<sub>k</sub> == endWord</code></li>
</ul>
<p>给你两个单词 <code>beginWord</code><code>endWord</code> ,以及一个字典 <code>wordList</code> 。请你找出并返回所有从 <code>beginWord</code><code>endWord</code><strong>最短转换序列</strong> ,如果不存在这样的转换序列,返回一个空列表。每个序列都应该以单词列表<em> </em><code>[beginWord, s<sub>1</sub>, s<sub>2</sub>, ..., s<sub>k</sub>]</code> 的形式返回。</p>
<p>&nbsp;</p>
<p><strong>示例 1</strong></p>
<pre>
<strong>输入:</strong>beginWord = "hit", endWord = "cog", wordList = ["hot","dot","dog","lot","log","cog"]
<strong>输出:</strong>[["hit","hot","dot","dog","cog"],["hit","hot","lot","log","cog"]]
<strong>解释:</strong>存在 2 种最短的转换序列:
"hit" -&gt; "hot" -&gt; "dot" -&gt; "dog" -&gt; "cog"
"hit" -&gt; "hot" -&gt; "lot" -&gt; "log" -&gt; "cog"
</pre>
<p><strong>示例 2</strong></p>
<pre>
<strong>输入:</strong>beginWord = "hit", endWord = "cog", wordList = ["hot","dot","dog","lot","log"]
<strong>输出:</strong>[]
<strong>解释:</strong>endWord "cog" 不在字典 wordList 中,所以不存在符合要求的转换序列。
</pre>
<p>&nbsp;</p>
<p><strong>提示:</strong></p>
<ul>
<li><code>1 &lt;= beginWord.length &lt;= 5</code></li>
<li><code>endWord.length == beginWord.length</code></li>
<li><code>1 &lt;= wordList.length &lt;= 5000</code></li>
<li><code>wordList[i].length == beginWord.length</code></li>
<li><code>beginWord</code><code>endWord</code><code>wordList[i]</code> 由小写英文字母组成</li>
<li><code>beginWord != endWord</code></li>
<li><code>wordList</code> 中的所有单词 <strong>互不相同</strong></li>
</ul>
</div>
</div>