设A和B是2个字符串。要用最少的字符操作将字符串A转换为字符串B。这里所说的字符操作包括：

1.　　删除一个字符

2.　　插入一个字符

3.　　将一个字符改为另一个字符

将字符串A变换为字符串B所用的最少操作数称为A到B的编辑距离，极为d(A,B)。设计一个算法，计算任意两个字符串的编辑距离。

-Set A and B are two strings. Operation will use the least character string A is converted to a string B. Operation of characters are talking about here include: 1. Delete a character 2. Insert a character 3. Will be replaced by one character to another character will be transformed into a string A string of at least B operand used by A to B is called the edit distance is extremely d (A, B). Design an algorithm to calculate any two of the string edit distance.