C Program to Multiply to Matrix Using Multi-dimensional Arrays

This program asks user to enter two matrices and this program multiplies these two matrix and displays it. If you don't know matrix multiplication, visit this page to learn, how two matrix can be multiplied.

Source code to multiply to matrix in C programming

#include <stdio.h>

int main()

{

    int a[10][10], b[10][10], mult[10][10], r1, c1, r2, c2, i, j, k;

    printf("Enter rows and column for first matrix: ");

    scanf("%d%d", &r1, &c1);

    printf("Enter rows and column for second matrix: ");

    scanf("%d%d",&r2, &c2);

/* If colum of first matrix in not equal to row of second matrix, asking user to enter the size of matrix again. */

    while (c1!=r2)

    {

        printf("Error! column of first matrix not equal to row of second.\n");

        printf("Enter rows and column for first matrix: ");

        scanf("%d%d", &r1, &c1);

        printf("Enter rows and column for second matrix: ");

        scanf("%d%d",&r2, &c2);

    }

/* Storing elements of first matrix. */

    printf("\nEnter elements of matrix 1:\n");

    for(i=0; i<r1; ++i)

    for(j=0; j<c1; ++j)

    {

        printf("Enter elements a%d%d: ",i+1,j+1);

        scanf("%d",&a[i][j]);

    }

/* Storing elements of second matrix. */

    printf("\nEnter elements of matrix 2:\n");

    for(i=0; i<r2; ++i)

    for(j=0; j<c2; ++j)

    {

        printf("Enter elements b%d%d: ",i+1,j+1);

        scanf("%d",&b[i][j]);

    }

/* Initializing elements of matrix mult to 0.*/

    for(i=0; i<r1; ++i)

    for(j=0; j<c2; ++j)

    {

       mult[i][j]=0;

    }

/* Multiplying matrix a and b and storing in array mult. */

    for(i=0; i<r1; ++i)

    for(j=0; j<c2; ++j)

    for(k=0; k<c1; ++k)

    {

        mult[i][j]+=a[i][k]*b[k][j];

    }

/* Displaying the multiplication of two matrix. */

    printf("\nOutput Matrix:\n");

    for(i=0; i<r1; ++i)

    for(j=0; j<c2; ++j)

    {

        printf("%d  ",mult[i][j]);

        if(j==c2-1)

            printf("\n\n");

    }

    return 0;

}