Method setZeroes

73. Set Matrix Zeroes/Solution.cpp:55–79

constant space

    // constant space
    void setZeroes(vector<vector<int>>& matrix) {
        bool frow = false;
        for (int i=0; i<matrix.size(); i++) {
            for (int j=0; j<matrix[0].size(); j++) {
                if ( matrix[i][j] == 0 ) {
                    if (i == 0) frow = true;
                    else matrix[i][0] = 0;
                    matrix[0][j] = 0;
                }
            }
        }
        for (int i=1; i<matrix.size(); i++) {
            for (int j=1; j<matrix[0].size(); j++) {
                if (matrix[i][0] == 0 or matrix[0][j] == 0)
                    matrix[i][j] = 0;
            }
        }
        if (matrix[0][0] == 0)
            for (int i=0; i<matrix.size(); i++)
                matrix[i][0] = 0;
        if (frow)
            for (int j=0; j<matrix[0].size(); j++)
                matrix[0][j] = 0;
        
    }
};

int main() {