Word Ladder
Question
Given a set of valid words, determine the minimum number of single-character transformations it would take to transform from a starting word to an ending word.
If there is not a possible way to transform frome one word to another, then return 0.
Input: start = "cat", end = "dog", words = set(["cat", "cot", "hot", "dog", "dot"])
Output: 3
It would take a minimum of 3 single-character transformations to transform from "cat" to "dog": "cat" => "cot" => "dot" => "dog".
Input: start = "hot", end = "cog", words = set(["cog", "dot", "fog", "lot", "hot", "job"])
Output: 0
There is no way to transform from "hot" to "cog" one letter at a time based on the words available in word_set.
Input: start = "hot", end = "cog", words = set(["cod", "cog", "cot", "fog", "rod", "rot", "hot", "job"])
Output: 2
Though there are multiple ways to transform from "hot" to "cog", the most minimum steps required is 2 tranformations: "hot" => "cot" => "cog".
Clarify the problem
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Understand the problem
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