Given a string, an edit script is a set of instructions to turn it into another string. There are four kinds of instructions in an edit script: Add (‘a’): Output one character. This instruction does not consume any characters from the source string. Delete (‘d’): Delete one character. That is, consume one character from the source string and output nothing. Modify (‘m’): Modify one character. That is, consume one character from the source string and output a character. Copy (‘c’): Copy one character. That is, consume one character from the source string and output the same character. Now, We define that A shortest edit script is an edit script that minimizes the total number of adds and deletes. Given two strings, generate a shortest edit script that changes the first into the second.
输入解释
The input consists of two strings on separate lines. The strings contain only alphanumeric characters. Each string has length between 1 and 10000, inclusive.
输出解释
The output is a shortest edit script. Each line is one instruction, given by the one-letter code of the instruction (a, d, m, or c), followed by a space, followed by the character written (or deleted if the instruction is a deletion).
In case of a tie, you must generate shortest edit script, and must sort in order of a , d, m, c. Therefore, there is only one answer.