2661. First Completely Painted Row or Column

class Solution {
public:
    int firstCompleteIndex(vector<int>& arr, vector<vector<int>>& mat) {
        int n=mat.size(),m=mat[0].size();
        unordered_map<int,pair<int,int>>mp;

        vector<int>rowCount(n),colCount(m);

        for(int row=0;row<n;row++){
            for(int col=0;col<m;col++){
                int val=mat[row][col];

                mp[val]={row,col};
            }
        }

        for(int i=0;i<arr.size();i++){
            int num=arr[i];

            pair<int,int>curr=mp[num];

            int row=curr.first;
            int col=curr.second;

            rowCount[row]++;
            colCount[col]++;


            if(rowCount[row]==m || colCount[col]==n)return i;
        }
        return -1;
    }
};