class Solution {
public:
    string frequencySort(string s) 
    {
        vector< pair<int,char> > v;
        string t;
        map<char,int> mp;
        int i,q;
        for(i=0;i<s.length();i++)
        {
            mp[s[i]]++;
        }
        for(auto it:mp)
        {
            v.push_back({it.second,it.first});
        }
        sort(v.begin(),v.end(),greater< pair<int,char> >());
        for(i=0;i<v.size();i++)
        {
            q=v[i].first;
            while(q--)
            {
            t=t+(v[i].second);
            }
        }
        return t;
    }
};