SolvedProblems/MatrixBlockSum.cc at main · mucahitrtn/SolvedProblems · GitHub

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/* REAL INTERVIEW QUESTION*/
// LeetCode
// 1314. Matrix Block Sum

class Solution {
public:

    void sum(vector<vector<int>>& mat, int cmin, int cmax, int rmin, int rmax , int i, int j, vector<vector<int>>& ans){
        int temp=0;
        for(int r=rmin; r<=rmax; r++){
            for(int c=cmin; c<=cmax; c++){
                temp+= mat[r][c];
            }
        }

        ans[i][j] += temp;

    }

    vector<vector<int>> matrixBlockSum(vector<vector<int>>& mat, int K) {
        int m = mat.size();
		int n = mat[0].size();
        vector<vector<int>> ans(m , vector<int>(n, 0));

        for(int i=0; i<m; i++){

            for(int j=0; j<mat[i].size(); j++){

                int rmin = ((i - K) < 0 ? 0 : (i - K));
				int rmax = (i + K) >= mat.size() ? (mat.size() - 1) : (i + K);
				int cmin = ((j - K) < 0 ? 0 : (j - K));
				int cmax = (j + K) >= mat[i].size() ? (mat[i].size() - 1) : (j + K);

                sum(mat, cmin, cmax, rmin, rmax, i, j, ans);

            }
        }


        return ans;
    }
};