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

void mm(double* a, double* b, double* c, int width){
	for (int i = 0; i < width; i++) {
		for (int j = 0; j < width; j++) {
			double sum = 0;for (int k = 0; k < width; k++) {
				double x = a[i * width + k];
				double y = b[k * width + j];
				sum += x * y;
			}
			c[i * width + j] = sum;
		}
	}
}

int main(){
	int width = 2000;
	double *a = (double*) malloc (width * width * sizeof(double));
	double *b = (double*) malloc (width * width * sizeof(double));
	double *c = (double*) malloc (width * width * sizeof(double));
	for(int i = 0; i < width; i++) {
		for(int j = 0; j < width; j++) {
			a[i*width+j] = i;
			b[i*width+j] = j;
			c[i*width+j] = 0;
		}
	}

	mm(a,b,c,width);
	//  for(int i = 0; i < width; i++) {
	//  for(int j = 0; j < width; j++) {
	//    printf("\n c[%d][%d] = %f",i,j,c[i*width+j]);
	//  }
	// }}