Package g0101_0200.s0127_word_ladder

Class Solution

java.lang.Object

g0101_0200.s0127_word_ladder.Solution

public class Solution
extends Object

127 - Word Ladder\. Hard A **transformation sequence** from word `beginWord` to word `endWord` using a dictionary `wordList` is a sequence of words beginWord -> s1 -> s2 -> ... -> sk such that: * Every adjacent pair of words differs by a single letter. * Every si for `1 <= i <= k` is in `wordList`. Note that `beginWord` does not need to be in `wordList`. * sk == endWord Given two words, `beginWord` and `endWord`, and a dictionary `wordList`, return _the **number of words** in the **shortest transformation sequence** from_ `beginWord` _to_ `endWord`_, or_ `0` _if no such sequence exists._ **Example 1:** **Input:** beginWord = "hit", endWord = "cog", wordList = ["hot","dot","dog","lot","log","cog"] **Output:** 5 **Explanation:** One shortest transformation sequence is "hit" -> "hot" -> "dot" -> "dog" -> cog", which is 5 words long. **Example 2:** **Input:** beginWord = "hit", endWord = "cog", wordList = ["hot","dot","dog","lot","log"] **Output:** 0 **Explanation:** The endWord "cog" is not in wordList, therefore there is no valid transformation sequence. **Constraints:** * `1 <= beginWord.length <= 10` * `endWord.length == beginWord.length` * `1 <= wordList.length <= 5000` * `wordList[i].length == beginWord.length` * `beginWord`, `endWord`, and `wordList[i]` consist of lowercase English letters. * `beginWord != endWord` * All the words in `wordList` are **unique**.

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
int	ladderLength(String beginWord, String endWord, List<String> wordDict)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Solution

public Solution()

Method Details

ladderLength

public int ladderLength(String beginWord,
 String endWord,
 List<String> wordDict)