9.Write a program to compute the multiplication of two n × m matrices.

// Write a program to compute the multiplication of two n × m matrices.
#include<stdio.h>
int main()
{
    int a1[3][3] = {{1,2,3}, {4,5,6}, {7,8,9}};
    int a2[3][3] = {{1,4,7}, {2,5,8}, {3,6,9}};
    int mat[3][3] = {0};
    int sum = 0;
    // Computing
    for (int i = 0; i < 3; ++i)
    {
        for (int j = 0; j < 3; ++j)
        {
            for (int k = 0; k < 3; ++k)
            {
                sum += a1[i][k] * a2[k][j];
            }
            mat[i][j] = sum;
            sum = 0;
        }
    }
    // Print multiplication of two n × m matrices
    for (int i = 0; i < 3; ++i)
    {
        for (int j = 0; j < 3; ++j)
            printf("%d ", mat[i][j]);
        printf("\n");
    }
    return 0;
}