eg_elist.ex.c

This is a working (althought useless) example on EGeList.

/* EGlib "Efficient General Library" provides some basic structures and
 * algorithms commons in many optimization algorithms.
 *
 * Copyright (C) 2005 Daniel Espinoza and Marcos Goycoolea.
 * 
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by the
 * Free Software Foundation; either version 2.1 of the License, or (at your
 * option) any later version.
 *
 * This library 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 Lesser General Public 
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA 
 * */
/** @file
 * @ingroup EGeList
 * */
/** @addtogroup EGeList */
/** @{ */
#include "eg_elist.h"
/* ========================================================================= */
/**@brief example of integer number lists structure based on embeded lists. */
typedef struct
{
  int n;        /**< actual information contained in the list */
  EGeList_t cn; /**< structure to put this together in a list */
}
integer_list_t;

/* ========================================================================= */
/** @brief A simple example of using embeded lists
 * @return zero on success, non-zero otherwise.
 * @par Description:
 * Show how to use embeded lists in a dynamic way and in a static fashion. */
int main (void)
{
  int rval = 0;
  integer_list_t number[20],
   *n_ptr;
  EGeList_t head,
    back_up,
   *it,
   *itn;
  int i;

  /* initialize the list */
  EGeListInit (&head);
  EGeListInit (&back_up);
  /* check that the list is non empty */
  if (EGeListIsEmpty (&head))
    fprintf (stderr, "List is empty at beginning\n");
  /* add all elements to the list and set some value */
  for (i = 0; i < 20; i++)
  {
    number[i].n = random () % 500;
    EGeListAddBefore (&(number[i].cn), &head);
  }
  /* display all elements in the list */
  fprintf (stderr, "Numbers in the list:\n");
  for (it = head.next, i = 0; it != &head; it = it->next, i++)
  {
    n_ptr = EGcontainerOf (it, integer_list_t, cn);
    fprintf (stderr, "(%d,%d) ", n_ptr->n, number[i].n);
  }
  fprintf (stderr, "\n");
  /* now we eliminate all even elements in the list, and display the
   * deleted element */
  fprintf (stderr, "Eliminating values:\n");
  for (i = 0; i < 10; i++)
  {
    it = EGeListDel (&(number[i << 1].cn));
    n_ptr = EGcontainerOf (it, integer_list_t, cn);
    fprintf (stderr, "%d ", n_ptr->n);
  }
  fprintf (stderr, "\n");
  /* and display the remaining list */
  fprintf (stderr, "Numbers in the list:\n");
  for (it = head.next, i = 0; it != &head; it = it->next, i++)
  {
    n_ptr = EGcontainerOf (it, integer_list_t, cn);
    fprintf (stderr, "(%d,%d) ", n_ptr->n, number[(i << 1) + 1].n);
  }
  fprintf (stderr, "\n");
  /* now we move halve of the members in the list to back_up list, note
   * however that as it is we can't move tyhe current element and then ask for
   * the next one, because after we move the entry, the next in the for loop
   * is the head of the back_up list */
  for (it = head.next, i = 0; it != &head; i++)
  {
    itn = it->next;
    if (i % 2 == 0)
      EGeListMoveBefore (it, &back_up);
    it = itn;
  }
  /* now we display both lists */
  fprintf (stderr, "head: ");
  for (it = head.next; it != &head; it = it->next)
  {
    n_ptr = EGcontainerOf (it, integer_list_t, cn);
    fprintf (stderr, "%d ", n_ptr->n);
  }
  fprintf (stderr, "\nback_up: ");
  for (it = back_up.next; it != &back_up; it = it->next)
  {
    n_ptr = EGcontainerOf (it, integer_list_t, cn);
    fprintf (stderr, "%d ", n_ptr->n);
  }
  fprintf (stderr, "\n");
  /* now we splice both lists into back_up list, and reset the head list */
  EGeListSplice (&head, &back_up);
  EGeListInit (&head);
  /* now we display both lists */
  fprintf (stderr, "head: ");
  for (it = head.next; it != &head; it = it->next)
  {
    n_ptr = EGcontainerOf (it, integer_list_t, cn);
    fprintf (stderr, "%d ", n_ptr->n);
  }
  fprintf (stderr, "\nback_up: ");
  for (it = back_up.next; it != &back_up; it = it->next)
  {
    n_ptr = EGcontainerOf (it, integer_list_t, cn);
    fprintf (stderr, "%d ", n_ptr->n);
  }
  fprintf (stderr, "\n");
  /* now we replace one member in back_up list with one of the deleted ones
   * from the complete original list and print the resulting list */
  EGeListReplace (back_up.next, &(number[0].cn));
  fprintf (stderr, "back_up: ");
  for (it = back_up.next; it != &back_up; it = it->next)
  {
    n_ptr = EGcontainerOf (it, integer_list_t, cn);
    fprintf (stderr, "%d ", n_ptr->n);
  }
  fprintf (stderr, "\n");
  return rval;
}

/* ========================================================================= */
/** @} */

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