/**@fileFunctions and structures for implementing a minimizing priority queue.Copyright (C) 2006  Rob Hess <hess@eecs.oregonstate.edu>@version 1.1.1-20070330*/#ifndef MINPQ_H#define MINPQ_H#include <stdlib.h>/******************************* Defs and macros *****************************//* initial # of priority queue elements for which to allocate space */#define MINPQ_INIT_NALLOCD 512/********************************** Structures *******************************//** an element in a minimizing priority queue */struct pq_node{	void* data;	int key;};/** a minimizing priority queue */struct min_pq{	struct pq_node* pq_array;    /* array containing priority queue */	int nallocd;                 /* number of elements allocated */	int n;                       /**< number of elements in pq */};/*************************** Function Prototypes *****************************//**Creates a new minimizing priority queue.*/extern struct min_pq* minpq_init();/**Inserts an element into a minimizing priority queue.@param min_pq a minimizing priority queue@param data the data to be inserted@param key the key to be associated with \a data@return Returns 0 on success or 1 on failure.*/extern int minpq_insert( struct min_pq* min_pq, void* data, int key );/**Returns the element of a minimizing priority queue with the smallest keywithout removing it from the queue.@param min_pq a minimizing priority queue@return Returns the element of \a min_pq with the smallest key or NULL	if \a min_pq is empty*/extern void* minpq_get_min( struct min_pq* min_pq );/**Removes and returns the element of a minimizing priority queue with thesmallest key.@param min_pq a minimizing priority queue@return Returns the element of \a min_pq with the smallest key of NULL	if \a min_pq is empty*/extern void* minpq_extract_min( struct min_pq* min_pq );/**De-allocates the memory held by a minimizing priorioty queue@param min_pq pointer to a minimizing priority queue*/extern void minpq_release( struct min_pq** min_pq );#endif