#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <omp.h>
int main()
{
const int DIM = 1000;
int i,j,k;
double debut, fin, temps;
double **a, **b, **cresu, **ctest;
a= (double**) malloc(DIM*sizeof(double*)); b= (double**) malloc(DIM*sizeof(double*)); cresu= (double**) malloc(DIM*sizeof(double*)); ctest= (double**) malloc(DIM*sizeof(double*));
// initialisations etc...
for (**0; i<DIM; i++)
    {
a[i]=(double*) malloc(DIM*sizeof(double)); b[i]=(double*) malloc(DIM*sizeof(double)); cresu[i]=(double*) malloc(DIM*sizeof(double)); ctest[i]=(double*) malloc(DIM*sizeof(double)); for (j = 0; j < DIM; j++)
{
a[i][j] = (double)(i-j); b[i][j] = (double)(i+j); cresu[i][j] = 0.0; ctest[i][j] = 0.0;
}
}
// Multiplication C = A x B (séquentiel)
printf("Multiplication sequentielle:\n");
debut= omp_get_wtime();
for (i = 0; i < DIM; i++)
for (j = 0; j < DIM; j++)
for (k = 0; k < DIM; k++)
ctest[i][j] += a[i][k] * b[k][j];
fin= omp_get_wtime();
temps=fin-debut;
printf ("Calcul sequentiel %f secondes\n", temps);
// Multiplication C = A x B (parallèle)
 printf("Multiplication parallele:\n");
 debut= omp_get_wtime();

#pragma omp parallel for num_threads(8) private(j,k)

for (i = 0; i < DIM; i++)
for (j = 0; j < DIM; j++)
for (k = 0; k < DIM; k++)
ctest[i][j] += a[i][k] * b[k][j];
fin= omp_get_wtime();
temps=fin-debut;
printf ("Calcul parallele %f secondes\n", temps);

}