class Solution {
public:
    vector<string> topKFrequent(vector<string>& words, int k) {
        map<string,int> countmap;
        for(auto& str : words)
        countmap[str]++;

        multimap<int,string,greater<int>> sortmap;
        for(auto& kv : countmap)
        sortmap.insert(make_pair(kv.second,kv.first));

        vector<string> ans;
        auto it = sortmap.begin();
        for(int i=0;i<k;i++)
        {
            ans.push_back(it->second);
            it++;
        } 
        return ans;
    }
};