#include <stdio.h>
#include <omp.h>
int main()
{
  int i_am, k, v[5]; v[0]=v[1]=v[2]=v[3]=v[4]=-1;

  /* Max number of procs and threads. */
  printf("num_procs   = %d\n", omp_get_num_procs());
  printf("max_threads = %d\n", omp_get_max_threads());

  /* I have given the following unix-command: 
       setenv OMP_NUM_THREADS 10  (4 is enough). */

  /* Set no. of threads dynamically. */
  omp_set_num_threads(4);

  /* A parallel section. Note { }. */
  #pragma omp parallel private(i_am) shared(v)
  {
    #pragma omp single
    printf("num_threads = %d\n", omp_get_num_threads());

    i_am    = omp_get_thread_num();
    v[i_am] = i_am;
  }
  printf("v = %d  %d  %d  %d  %d\n",
          v[0], v[1], v[2], v[3], v[4]);

  /* A parallel for-loop. */
  #pragma omp parallel for private(k) shared(v)
  for(k = 0; k < 5; k++)
    v[k] = k * k;

  printf("v = %d  %d  %d  %d  %d\n",
          v[0], v[1], v[2], v[3], v[4]);

  return 0;
}