Solution: Word Ladder II
Explore how to solve the Word Ladder II problem by combining breadth-first search to identify shortest transformation sequences and depth-first search backtracking to reconstruct all valid paths. Learn the algorithm's two-phase approach, including efficient neighbor generation, parent tracking, and path enumeration, to handle complex transformations with optimal time and space complexity.
We'll cover the following...
Statement
You are given two words, beginWord and endWord, and a dictionary of words called wordList. Your task is to find all the shortest transformation sequences from beginWord to endWord, such that:
Only one letter can be changed at a time.
Each transformed word must exist in the given
wordList.The transformation sequence must begin with
beginWordand end withendWord.
Return all the shortest transformation sequences as a list of lists. If no valid transformation exists, return an empty list.
Constraints:
...