// matmul.c  for compare with  omp_matmul.c

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>

#define DIM 1000
static  double a[DIM][DIM];
static  double b[DIM][DIM];
static  double c[DIM][DIM];

int main(int argc, char *argv[])
{
  int i, j, k;
  double sum;
  double twall, tcpu;

  printf("matmu.c running, DIM = %d \n", DIM);

  for(i=0; i<DIM; i++)
  {
    for(j=0; j<DIM; j++)
    {
      a[i][j] = (double)(i+j);
      b[i][j] = (double)(i+j+1);
    }
  }

  twall = (double)time(NULL);
  tcpu = (double)clock()/(double)CLOCKS_PER_SEC;

  for(i=0; i<DIM; i++)
  {
    for(j=0; j<DIM; j++)
    {
      sum=0.0;
      for(k=0; k<DIM; k++)
      {
        sum += a[i][k]*b[k][j];
      } // end k
      c[i][j]=sum;
    } // end j
  } // end i

  printf("c[1][1]=%f, c[2][2]=%f \n", c[1][1], c[2][2]);
  printf("took %f wall sec, %f cpu sec \n",
	 (double)time(NULL)-twall,
	 (double)clock()/(double)CLOCKS_PER_SEC-tcpu);
 
  return(0);
} // end matmul.c