/* Copyright (c) 2008, Geoffrey Foster
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the <organization> nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Geoffrey Foster ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL Geoffrey Foster BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef __PAIRING_HEAP_H
#define __PAIRING_HEAP_H

#include <stdlib.h>
#include <stdbool.h>

typedef int (*pairing_heap_cmp)(const void*, const void*);

typedef struct tag_pairing_heap_node {
	struct tag_pairing_heap_node *left;
	struct tag_pairing_heap_node *sibling;
	struct tag_pairing_heap_node *prev;
	const void *data;
	void *priority;
} pairing_heap_node;

typedef struct {
	pairing_heap_node *root;
	pairing_heap_cmp cmp;
	size_t size;
	struct {
		pairing_heap_node **array;
		size_t n;
	} tree_array;
} pairing_heap;

typedef pairing_heap_node *pairing_heap_item;

bool pairing_heap_create(pairing_heap*, pairing_heap_cmp);
bool pairing_heap_cleanup(pairing_heap*);
bool pairing_heap_insert(pairing_heap*, void*, const void*, pairing_heap_item*);
bool pairing_heap_find_min(pairing_heap*, pairing_heap_item*);
const void *pairing_heap_delete_min(pairing_heap*);
size_t pairing_heap_size(pairing_heap*);
const void *pairing_heap_get_data(pairing_heap_item);

#endif /* __PAIRING_HEAP_H */