Strings Homomorphism

Given two strings s and t, determine if they are isomorphic.

Two strings are isomorphic if the characters in s can be replaced to get t.

All occurrences of a character must be replaced with another character while preserving the order of characters. No two characters may map to the same character but a character may map to itself.

 注意事项

You may assume both s and t have the same length.

您在真实的面试中是否遇到过这个题？ 

Yes

样例

Given s = "egg", t = "add", return true.

Given s = "foo", t = "bar", return false.

Given s = "paper", t = "title", return true.

解题思路：用两个map进行记录，若每个map的值对应全部相等则返回true，否则false。

解题代码：

class Solution {public:    /**     * @param s a string     * @param t a string     * @return true if the characters in s     * can be replaced to get t or false     */    bool isIsomorphic(string& s, string& t) {        // Write your code here        if(s.size()!=t.size())return false;    map<char,int>test,comp;    for(int i=0;i<=s.size();i++)test[s[i]]++,comp[t[i]]++;    int flag=0;    for(int i=0;i<=s.size();i++){            if(flag)break;            if(test[s[i]]!=comp[t[i]])flag=1;    }    if(flag)return false;    return true;    }};