I was doing the problem : **http://oj.leetcode.com/problems/word-ladder/**, in which I applied BFS type approach on an undirected graph.. For the given test case (attached below) I think we can achieve the transformation in a single step, by going from **"a" - > "c"** , wherein both the said words exist in the dictionary , and the resulting transformation requires minimum steps. Why is the answer then **2**?

Input: "a", "c", ["a","b","c"]

Output: 1

Expected: 2