/* multiset/init.c

 * based on combination/init.c by Szymon Jaroszewicz

 * based on permutation/init.c by Brian Gough

 *

 * Copyright (C) 2001 Szymon Jaroszewicz

 * Copyright (C) 2009 Brian Gough

 * Copyright (C) 2009 Rhys Ulerich

 *

 * 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.

 */

#include <config.h>

#include <stdlib.h>

#include <gsl/gsl_errno.h>

#include <gsl/gsl_multiset.h>

gsl_multiset *

gsl_multiset_alloc (const size_t n, const size_t k)

{

  gsl_multiset * c;

  if (n == 0)

    {

      GSL_ERROR_VAL ("multiset parameter n must be positive integer",

                        GSL_EDOM, 0);

    }

  c = (gsl_multiset *) malloc (sizeof (gsl_multiset));

  if (c == 0)

    {

      GSL_ERROR_VAL ("failed to allocate space for multiset struct",

                        GSL_ENOMEM, 0);

    }

  if (k > 0)

    {

      c->data = (size_t *) malloc (k * sizeof (size_t));

      if (c->data == 0)

        {

          free (c);             /* exception in constructor, avoid memory leak */

          GSL_ERROR_VAL ("failed to allocate space for multiset data",

                         GSL_ENOMEM, 0);

        }

    }

  else

    {

      c->data = 0;

    }

  c->n = n;

  c->k = k;

  return c;

}

gsl_multiset *

gsl_multiset_calloc (const size_t n, const size_t k)

{

  size_t i;

  gsl_multiset * c =  gsl_multiset_alloc (n, k);

  if (c == 0)

    return 0;

  /* initialize multiset to repeated first element */

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

    {

      c->data[i] = 0;

    }

  return c;

}

void

gsl_multiset_init_first (gsl_multiset * c)

{

  const size_t k = c->k ;

  size_t i;

  /* initialize multiset to repeated first element */

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

    {

      c->data[i] = 0;

    }

}

void

gsl_multiset_init_last (gsl_multiset * c)

{

  const size_t k = c->k ;

  size_t i;

  size_t n = c->n;

  /* initialize multiset to repeated last element */

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

    {

      c->data[i] = n - 1;

    }

}

void

gsl_multiset_free (gsl_multiset * c)

{

  RETURN_IF_NULL (c);

  if (c->k > 0) free (c->data);

  free (c);

}