1209

class Solution {
public:
    string removeDuplicates(string s, int k) {
        vector< pair<char, int> > v = {{0,'#'}};
        for(char c: s){
            if(v.back().first != c){
                v.push_back({c, 1});
            }
            else if(++v.back().second == k){
                v.pop_back();
            }
        }
        string ans = "";
        for(int i=1; i<v.size(); i++){
            ans.append(v[i].second, v[i].first);
        }
        return ans;
    }
};