Thread: matrix

Got a program to multiply 2 matrices. Below is my source code:

Code:

#include "stdio.h"
#include "conio.h"

void main()
{
   static int a[10] [10];
   static int b[10] [10];
   static int c[10] [10];

   int i,j,k,l,m,n,p,q;

   clrscr();

   printf ("Put the dimension for array A ,i.e. row x column \n");
   scanf ("%d %d",&m,&n);

   printf ("Put the dimension for array B ,i.e. row x column \n");
   scanf ("%d %d",&p,&q);

   if (n!=p)
   {
      printf("Multiplication of matrices is not possible \n");

      printf ("Dimension of matrices is not valid");

   }

   else
   {

     
      printf ("Input the element in the array A \n");


      for (i=0; i<m; i++)
      {

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

	 }

      }

      printf("\nThe array  A is as follows \n");


      for(i=0; i<m; i++)
      {

	 for(j=0;j<n;j++)
	 {

	
	    printf("%d ", a[i][j]);

	 }
	 printf("\n");

     }

      
      
      printf ("\nInput the elements in the array B \n");


      for (k=0; k<p; k++)
      {

	 
	 for (l=0; l<q; l++)
	 {

	    scanf ("%d",&b[k] [l]);
	 }
      }

      printf("\nThe array b is as follows: \n");

      for(k=0;k<p;k++)
      {

	 for(l=0;l<q;l++)
	 {
	    printf("%d ", b[k][l]);

	 }
                 printf("\n");
       }

      for (i=0; i<m; i++)
      {
	 for (l=0; l<q; l++)
	 {
	    for (j=0; j<n; j++)
	    {
	       c[i] [l] = c[i] [l] + a[i] [j] * b[j] [l];
	    }

	
	 }

      }
      printf("\n");
      printf("The result is as follows: \n");

      for (i=0; i<m; i++)
      {
	   l=0;
	   while (l<q)
	   {
	      printf (" %d ",c[i] [l]);
	      l++;

	   }
                   printf ("\n");
      
      }
   
   }

   getch();
}

Do u think I can make it simpler?

Code:

for (i=0; i<m; i++)
{
	 for (l=0; l<q; l++)
	 {
	    for (j=0; j<n; j++)
	    {
	       c[i] [l] = c[i] [l] + a[i] [j] * b[j] [l];
                    }

	
	 }
}

The inner j loop can be unrolled. In this for/next structure the inner j loop will take longer than the m and l loops. You could also use a one dimensional array instead of a 2 to represent a matrix.

0 3 6
1 4 7
2 5 8

or

01 11 21
02 12 22
03 13 23