1.7 Write an algorithm such that if an element in an MxN matrix is 0, its entire row and column are set to 0.

1.7.cpp

#include<iostream>

using namespace std;

const int M = 3;
const int N = 4;

void setZeros(int matrix[][N])
{
    int row[M/sizeof(int)+1]{};
    int col[N/sizeof(int)+1]{};
    
    for (int i = 0; i < M; i++) {
        for (int j = 0; j < N; j++) {
            if (matrix[i][j] == 0) {
                row[i/sizeof(int)] |= 1 << i%sizeof(int);
                col[j/sizeof(int)] |= 1 << j%sizeof(int);
            }
        }
    }
    
    for (int i = 0; i < M; i++) {
        for (int j = 0; j < N; j++) {
            if ((row[i/sizeof(int)] & (1 << i%sizeof(int))) ||
                (col[j/sizeof(int)] & (1 << j%sizeof(int))))
                matrix[i][j] = 0;
        }
    }
}

void print(int matrix[][N])
{
    for (int nRow = 0; nRow < M; nRow++)
    {
        for (int nCol = 0; nCol < N; nCol++)
            cout << matrix[nRow][nCol] << "\t";
        
        cout << endl;
    }
}

int main(int argc, char *argv[])
{
    int m[][N]{{1,2,3,4},{5,6,0,8},{9,10,11,12}};
    print(m);
    cout << endl;
    setZeros(m);
    print(m);
    return 0;
}