/* $Id: heap.h,v 1.1 2005/12/18 00:11:32 dj Exp $ */

/*
 *                            COPYRIGHT
 *
 *  PCB, interactive printed circuit board design
 *  Copyright (C) 1994,1995,1996 Thomas Nau
 *  Copyright (C) 1998,1999,2000,2001 harry eaton
 *
 *  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 2 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *  Contact addresses for paper mail and Email:
 *  harry eaton, 6697 Buttonhole Ct, Columbia, MD 21044 USA
 *  haceaton@aplcomm.jhuapl.edu
 *
 */

/* this file, heap.h, was written and is
 * Copyright (c) 2001 C. Scott Ananian.
 */

/* prototypes for heap routines.
 */

#ifndef __HEAP_INCLUDED__
#define __HEAP_INCLUDED__

#include "global.h"

/* type of heap costs.  *must be integer!* */ 
typedef float cost_t;
/* what a heap looks like */
typedef struct heap_struct heap_t;

/* create an empty heap */
heap_t * heap_create();
/* destroy a heap */
void heap_destroy(heap_t **heap);

/* -- mutation -- */
void heap_insert(heap_t *heap, cost_t cost, void *data);
void *heap_remove_smallest(heap_t *heap);
/* replace the smallest item with a new item and return the smallest item.
 * (if the new item is the smallest, than return it, instead.) */
void *heap_replace(heap_t *heap, cost_t cost, void *data);

/* -- interrogation -- */
int heap_is_empty(heap_t *heap);

#endif /* __HEAP_INCLUDED__ */