/*  Evgenii B. Rudnyi, http://Evgenii.Rudnyi.Ru */

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

#define dim1 1000
#define dim2 1000
#define dim3 1000

int main()
{
	double A[dim1*dim2], B[dim2*dim3], C[dim1*dim3];
	int i, j, k;
	double start, finish;
	double maxr;
	srand(86456);
	maxr = (double)RAND_MAX;
	for (i = 0; i < dim1; i++)
		for (j = 0; j < dim2; j++)
			A[i + j*dim1] = rand()/maxr;
	for (i = 0; i < dim2; i++)
		for (j = 0; j < dim3; j++)
			B[i + j*dim2] = rand()/maxr;
	start = clock();
	for (j = 0; j < dim3; j++)
	{
		for (i = 0; i < dim3; i++)
			C[i + j*dim1] = 0.;
		for (k = 0; k < dim2; k++)
			for (i = 0; i < dim1; i++)
				C[i + j*dim1] += A[i + k*dim1]*B[k + j*dim2];
	}
	finish = clock();
	printf("time for C(%d,%d) = A(%d,%d) B(%d,%d) is %f s\n", dim1, dim3, dim1, dim2, dim2, dim3, (finish - start)/CLK_TCK);	
	return 0;
}