/* sort/test_heapsort.c

 * 

 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Thomas Walter, Brian Gough

 * 

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 3 of the License, or (at

 * your option) any later version.

 * 

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 */

int cmp_dbl (const void *a, const void *b);

void test_heapsort (size_t N);

void initialize (double *data, size_t N);

void cpy (double *dest, double *src, size_t N);

void randomize (double *data, size_t n);

void reverse (double *data, size_t N);

int check (double *data, double *orig, size_t N);

int pcheck (size_t * p, double *data, double *orig, size_t N);

void

test_heapsort (size_t N)

{

  int status;

  double *orig = (double *) malloc (N * sizeof (double));

  double *data = (double *) malloc (N * sizeof (double));

  size_t  *p = (size_t *) malloc (N * sizeof(size_t));

  initialize (orig, N);

  /* Already sorted */

  cpy (data, orig, N);

  status = gsl_heapsort_index (p, data, N, sizeof (double), (gsl_comparison_fn_t) & cmp_dbl);

  status |= pcheck (p, data, orig, N);

  gsl_test (status, "indexing array, n = %u, ordered", N);

  gsl_heapsort (data, N, sizeof (double), (gsl_comparison_fn_t) & cmp_dbl);

  status = check (data, orig, N);

  gsl_test (status, "sorting, array, n = %u, ordered", N);

  /* Reverse the data */

  cpy (data, orig, N);

  reverse (data, N);

  status = gsl_heapsort_index (p, data, N, sizeof (double), (gsl_comparison_fn_t) & cmp_dbl);

  status |= pcheck (p, data, orig, N);

  gsl_test (status, "indexing array, n = %u, reversed", N);

  gsl_heapsort (data, N, sizeof (double), (gsl_comparison_fn_t) & cmp_dbl);

  status = check (data, orig, N);

  gsl_test (status, "sorting, array, n = %u, reversed", N);

  /* Perform some shuffling */

  cpy (data, orig, N);

  randomize (data, N);

  status = gsl_heapsort_index (p, data, N, sizeof (double), (gsl_comparison_fn_t) & cmp_dbl);

  status |= pcheck (p, data, orig, N);

  gsl_test (status, "indexing array, n = %u, randomized", N);

  gsl_heapsort (data, N, sizeof (double), (gsl_comparison_fn_t) & cmp_dbl);

  status = check (data, orig, N);

  gsl_test (status, "sorting, array, n = %u, randomized", N);

  free (orig);

  free (data);

  free (p);

}

void

initialize (double *data, size_t N)

{

  size_t i;

  for (i = 0; i < N; i++)

    {

      data[i] = i;

    }

}

void

cpy (double *dest, double *src, size_t N)

{

  size_t i;

  for (i = 0; i < N; i++)

    {

      dest[i] = src[i];

    }

}

void

randomize (double *data, size_t N)

{

  size_t i;

  for (i = 0; i < N; i++)

    {

      size_t j = urand (N);

      double tmp = data[i];

      data[i] = data[j];

      data[j] = tmp;

    }

}

void

reverse (double *data, size_t N)

{

  size_t i;

  for (i = 0; i < N / 2; i++)

    {

      size_t j = N - i - 1;

      {

        double tmp = data[i];

        data[i] = data[j];

        data[j] = tmp;

      }

    }

}

int

check (double *data, double *orig, size_t N)

{

  size_t i;

  for (i = 0; i < N; i++)

    {

      if (data[i] != orig[i])

        {

          return GSL_FAILURE;

        }

    }

  return GSL_SUCCESS;

}

int

pcheck (size_t * p, double *data, double *orig, size_t N)

{

  size_t i;

  for (i = 0; i < N; i++)

    {

      if (data[p[i]] != orig[i])

        {

          return GSL_FAILURE;

        }

    }

  return GSL_SUCCESS;

}

int

cmp_dbl (const void *a, const void *b)

{

  const double x = *(const double *) a;

  const double y = *(const double *) b;

  if (x > y)

    return 1;

  if (x == y)

    return 0;

  else

    return -1;

}