Archive:Matrix multiplication using C

/* Program to implement matrix multiplication. */
/* Performed by Milan. */

#include <stdio.h>
#include <conio.h>

void main()
{
	int a[10][10], b[10][10], c[10][10];
	int i, j, m, n, x, y, k;
	clrscr();

	/* Entering values for matrix a...*/
	printf ("\n Enter the rows and columns of a: ");
	scanf ("%d%d", &m, &n);

	for (i = 0; i < m; i++)
	{
		for (j = 0; j < n; j++)
		{
			printf (" a[%d][%d] = ", (i+1), (j+1));
			scanf ("%d", &a[i][j]);
		}
		printf ("\n");
	}

	/* Entering values for matrix b... */
	printf ("\n Enter the rows and columns of b: ");
	scanf ("%d%d", &x, &y);

	for (i = 0; i < x; i++)
	{
		for (j = 0; j < y; j++)
		{
			printf (" b[%d][%d] = ", (i+1), (j+1));
			scanf ("%d", &b[i][j]);
		}
		printf ("\n");
	}

	/* Calculations */
	if ( n != x)
	{
		printf ("\n Error!! Rows of a don't match with columns of b.");
		printf ("\n Multiplication Impossible.");
		getch();
		exit(0);
	}
	else
	{
		for (i = 0; i < m; i++)
		{
			for (j = 0; j < y; j++)
			{
				c[i][j] = 0;
				for (k = 0; k < n; k++)
				{
					c[i][j]+=a[i][k]*b[k][j];
				}
			}
		}
	}

	/* Output */
	printf ("\n The resultant c is:\n");
	for (i = 0; i < m; i++)
	{
		for (j = 0; j < y; j++)
		{
			printf (" c[%d][%d] = %d", (i+1), (j+1), c[i][j]);
		}
		printf ("\n");
	}

	getch();
}
/* Output:

 Enter the rows and columns of a: 2 2
 a[1][1] = 1
 a[1][2] = 2

 a[2][1] = 3
 a[2][2] = 4


 Enter the rows and columns of b: 2 2
 b[1][1] = 2
 b[1][2] = 1

 b[2][1] = 2
 b[2][2] = 2


 The resultant c is:
 c[1][1] = 6 c[1][2] = 5
 c[2][1] = 14 c[2][2] = 11
*/