/* Fills the |n| elements of |array[]| with a random permutation of the
   integers between |0| and |n - 1|. */
static void
permuted_integers (int array[], size_t n)
{
  size_t i;

  for (i = 0; i < n; i++)
    array[i] = i;

  for (i = 0; i < n; i++)
    {
      size_t j = i + (unsigned) rand () / (RAND_MAX / (n - i) + 1);
      int t = array[j];
      array[j] = array[i];
      array[i] = t;
    }
}