Introduction - If you have any usage issues, please Google them yourself
3.4 Description of the problem string game ★ contain only lowercase letters to the two non-empty string A, B, you can use the following three operations on strings for editing: 1. Remove any letter in any position 2. Insert a 3. Replace the alphabet one letter to another letter, we define the function d (A, B) for the string A string is converted into the number B of the minimum operation.