设A和B是两个字符串,要用最少的字符操作将A转换成B.允许的操作包括:1)删除一个字符 2)插入一个字符 3)将一个字符替换为另一个字符.将A转换成B所用的最少的字符操作数称为编辑距离。

设计算法，对任给的字符串A,B,计算他们的编辑距离。

输入：第一行字符串A；第二行字符串B

输出：第一行编辑距离-For A and B are two strings of characters to use at least A conversion operation will be allowed to operate as B., including: 1) delete a character　2) insert a character　3) the replacement of one character to another character. A into B will be used in operation for at least a few of the characters known as the edit distance. Design algorithm, for any string to the A, B, computing their edit distance. Input: the first line of string A　the second line of the output string B: the first line of edit distance