Word Ladder II

Given two words (start and end), and a dictionary, find all shortest transformation sequence(s) from start to end, such that: 1) Only one letter can be changed at a time, 2) Each intermediate word must exist in the dictionary. For example, given: start = “hit”, end = “cog”, and dict = [“hot”,”dot”,”dog”,”lot”,”log”], return: [ [“hit”,”hot”,”dot”,”dog”,”cog”], … Read more