242. 有效的字母异位词

class Solution {
public:
    map<char,int>mp1;
    map<char,int>mp2;
    bool isAnagram(string s, string t) {
        if(s.size()!=t.size())return false;
        for(auto k:s){
            mp1[k]++;
        }
        for(auto k:t){
            mp2[k]++;
        }
        for(auto k:s){
            if(mp1[k]!=mp2[k])return false;
        }
        return true;
    }
};