leetcode-205-isomorphic strings

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.

For example,
Given “egg”, “add”, return true.

Given “foo”, “bar”, return false.

Given “paper”, “title”, return true.

给定两个字符串，判断它们是否是相似的。

用两个哈希表判断两个字符之间是否是一一对应的即可。

class Solution {
public:
    bool isIsomorphic(string s, string t) {
        std::map<char,char> m;
        std::map<char,char> mr;
        std::map<char,char>::iterator it;
        std::map<char,char>::iterator itr;
        for(int i = 0; i < s.length(); i++)
        {  
           it  = m.find(s[i]);
           itr = mr.find(t[i]);
           if(it!=m.end()||itr!=mr.end())
           {
               if(m[s[i]]!=t[i]||mr[t[i]]!=s[i]) return false;
           }else{
               m[s[i]]=t[i];
               mr[t[i]]=s[i];
           }
        }
        return true;
    }
};