Word Ladder
Shortest transformation from beginWord to endWord using wordList Change one letter at a time; each intermediate word must be in wordList Return length of the shortest transformation, or 0 if impossible
Transform one word into another, changing one letter at a time, using only valid dictionary words. It's a shortest-path problem hiding behind a word puzzle—BFS finds the minimum steps. The insight is modeling words as graph nodes where edges connect words that differ by exactly one letter.
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