Word Ladder I

Given two words A and B, and a dictionary C, find the length of shortest transformation sequence from A to B, such that:

• You must change exactly one character in every transformation.
• Each intermediate word must exist in the dictionary.

NOTE:

• Return 0 if there is no such transformation sequence.
• All words have the same length.
• All words contain only lowercase alphabetic characters.

The first argument of input contains a string, A.

The second argument of input contains a string, B.

The third argument of input contains an array of strings, C.

Return an integer representing the minimum number of steps required to change string A to string B.

Input 1:

 A = "hit"
 B = "cog"
 C = ["hot", "dot", "dog", "lot", "log"]

Input 2:

 A = "cat"
 B = "bat"
 C = ["rat"]

Input 3:

 A = "bait"
 B = "pant"
 C = ["a","b"]

Output 1:

 5

Output 2:

 2

Output 3:

 0

Explanation 1:

 "hit" -> "hot" -> "dot" -> "dog" -> "cog"

Explanation 2:

 "cat" -> "bat"

Explanation 3:

 No intermediate words are present in the given dictionary so transformation is not possible. We will return 0 for this case.