(Java) Leetcode 127. Word ladder--Word Solitaire

Given words (beginword and Endword), and a dictionary ' s word list, find the length of shortest trans Formation sequence from Beginword to Endword, such that:

1. Only one letter can is changed at a time.
2. Each transformed word must exist in the word list. Note that Beginword was not a transformed word.

Note:

• Return 0 If there is no such transformation sequence.
• All words has the same length.
• All words contain only lowercase alphabetic characters.
• Assume no duplicates in the word list.
• Assume Beginword and Endword are non-empty and is not the same.

Example 1:

Input:beginword = "hit", Endword = "Cog", wordList = [' hot ', ' dot ', ' dog ', ' lot ', ' log ', ' cog ']output:5explanation:as one Shortest transformation is ' hit ', "Hot", "dot", "dog" and "cog", return its length 5.

Example 2:

Input:beginword = "hit" Endword = "cog" wordList = [' hot ', ' dot ', ' dog ', ' lot ', ' log ']output:0explanation:the Endword ' cog ' I s not in wordList, therefore no possible transformation.

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(Java) Leetcode 127. Word ladder--Word Solitaire