实现字符串间相同字符串的替换功能。若s中的字符在s1中出现，则用s2中的字符替换。-To achieve the same function between string replacement string. S If the characters appear in s1, then replace it with the character in s2.

关于两个字符串s1,s2的差别，可以通过计算他们的最小编辑距离来决定。用C++设计动态规划算法解决此类问题(The difference between the two strings s1, s2, can be determined by calculating their minimum edit distance.Using c + + design dynamic programming algorithm to solve these problems)