#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
#include <string.h>
#include <math.h>
#include <omp.h>
#include "aux.h"

void sequential_product(block **a, block **b, block **c, int n, int nb);
void parallel_product(block **a, block **b, block **c, int n, int nb);

int main(int argc, char **argv)
{
  int n, nb;
  long t_start, t_end;
  block **a, **b, **c, **d;

  // Command line argument: array length
  if (argc == 2)
  {
    n = atoi(argv[1]); /* for a matrix of size nxn blocks */
  }
  else
  {
    printf("Usage:\n\n ./main n\n\nwhere n is the number of blocks in rows and columns of the matrices.\n");
    return 1;
  }

  /* Statically fixed to 100, no need to change this unless for debugging */
  nb = 100;

  init_data(&a, &b, &c, &d, n, nb);

  /* Sequential version */
  t_start = usecs();
  sequential_product(a, b, c, n, nb);
  t_end = usecs();
  printf("Sequential   time    : %8.2f msec.\n", ((double)t_end - t_start) / 1000.0);

  /* Parallel with tasks */
  t_start = usecs();
  parallel_product(a, b, d, n, nb);
  t_end = usecs();
  printf("Parallel     time    : %8.2f msec.\n", ((double)t_end - t_start) / 1000.0);

  /* Comprare the two resulting matrices */
  compare_matrices(c, d, n, nb);
  return 0;
}

void sequential_product(block **a, block **b, block **c, int n, int nb)
{
  int i, j, k;

  for (i = 0; i < n; i++)
    for (j = 0; j < n; j++)
      for (k = 0; k < n; k++)
      {
        block_mult(a[i][k], b[k][j], c[i][j], nb);
      }
}

void parallel_product(block **a, block **b, block **c, int n, int nb)
{
  int i, j, k;

#pragma omp parallel private(i, j, k)
#pragma omp single

  for (i = 0; i < n; i++)
    for (j = 0; j < n; j++)
#pragma omp task firstprivate(i, j)
      for (k = 0; k < n; k++)
      {
        block_mult(a[i][k], b[k][j], c[i][j], nb);
      }
}