class Solution {
public:
    static bool cmp(const pair<string,int> &x , const pair<string,int> &y)
    {
        return (x.second == y.second) ? x.first < y.first : x.second > y.second;
    }

    vector<string> topKFrequent(vector<string>& words, int k) {
        vector<string> res;
        map<string,int> Mymap;
        for(auto word : words) Mymap[word]++;
        vector<pair<string,int>> v(Mymap.begin(), Mymap.end());
        sort(v.begin(), v.end(), cmp);
        int cnt = 0;
        for(auto iter = v.begin(); iter != v.end(); ++iter)
        {
            res.push_back(iter->first);
            cnt++;
            if(cnt==k) break;
        }
        return res;   
    }
};