#include <stdio.h>

#include <gsl/gsl_rng.h>

#include <gsl/gsl_randist.h>

#include <gsl/gsl_permutation.h>

int

main (void) 

{

  const size_t N = 10;

  const gsl_rng_type * T;

  gsl_rng * r;

  gsl_permutation * p = gsl_permutation_alloc (N);

  gsl_permutation * q = gsl_permutation_alloc (N);

  gsl_rng_env_setup();

  T = gsl_rng_default;

  r = gsl_rng_alloc (T);

  printf ("initial permutation:");  

  gsl_permutation_init (p);

  gsl_permutation_fprintf (stdout, p, " %u");

  printf ("\n");

  printf (" random permutation:");  

  gsl_ran_shuffle (r, p->data, N, sizeof(size_t));

  gsl_permutation_fprintf (stdout, p, " %u");

  printf ("\n");

  printf ("inverse permutation:");  

  gsl_permutation_inverse (q, p);

  gsl_permutation_fprintf (stdout, q, " %u");

  printf ("\n");

  gsl_permutation_free (p);

  gsl_permutation_free (q);

  gsl_rng_free (r);

  return 0;

}