//User function Template for C++

class Solution

{   

    public:

    vector<int> repeatedRows(vector<vector<int>> &matrix, int M, int N) 

    { 

        // Your code here

        map<vector<int>,int> mp;

        for(int i=0;i<M;i++) mp[matrix[i]]++;

        vector<int> ans;

        map<vector<int>,int> mp2;

        for(auto it : mp) {

            if(it.second>=2) mp2[it.first] = it.second;

        }

        for(auto it : mp2){

            deque<int> dq;

            for(int i=0;i<M;i++) {

                if(it.first==matrix[i]) dq.push_back(i);

            }

            dq.pop_front();

            ans.insert(ans.end(), dq.begin(), dq.end());

        }

        sort(ans.begin(),ans.end());

        return ans;

    } 

};