题目: Given two words (start and end), and a dictionary, find all shortest transformation sequence(s) from start to end, such that: Only one letter can be changed at a time Each intermediate word must exist in the dictionary For example, Given: start =…

Given two words (beginWord and endWord), and a dictionary's word list, find the length of shortest transformation sequence from beginWord to endWord, such that: Only one letter can be changed at a time. Each transformed word must exist in the word li…

(不会,经典广度优先搜索) 给定两个单词(beginWord 和 endWord)和一个字典,找到从 beginWord 到 endWord 的最短转换序列的长度.转换需遵循如下规则: 每次转换只能改变一个字母. 转换过程中的中间单词必须是字典中的单词. 说明: 如果不存在这样的转换序列,返回 0. 所有单词具有相同的长度. 所有单词只由小写字母组成. 字典中不存在重复的单词. 你可以假设 beginWord 和 endWord 是非空的,且二者不相同. 示例 1: 输入: beginWord…

class Solution { public int ladderLength(String beginWord, String endWord, List<String> wordList) { HashSet<String> wordSet = new HashSet<>(wordList); //替换掉题目中List结构,加速查找 if (!wordSet.contains(endWord)) return 0; //如果目标顶点不在图中,直接返回0 HashM…