Solution: Word Ladder II
Explore how to solve the Word Ladder II problem by using a two-phase approach combining breadth-first search to discover shortest transformation paths and depth-first search for backtracking all possible sequences. Learn to manage complex dictionary lookups efficiently and reconstruct all valid sequences while optimizing 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:
...