Functions for heap-based priority queues. More...

#include "ntr.h"

Include dependency graph for ntrHeap.c:

Data Structures
struct	NtrHeapSlot
	Entry of NtrHeap. More...

struct	NtrHeap
	Heap-based priority queue. More...

Macros
#define	PARENT(i) (((i)-1)>>1)

#define	RIGHT(i) (((i)+1)<<1)

#define	LEFT(i) (((i)<<1)\|1)

#define	ITEM(p, i) ((p)[i].item)

#define	KEY(p, i) ((p)[i].key)

Functions
NtrHeap *	Ntr_InitHeap (int size)
	Initializes a priority queue. More...

void	Ntr_FreeHeap (NtrHeap *heap)
	Frees a priority queue. More...

int	Ntr_HeapInsert (NtrHeap heap, void item, int key)
	Inserts an item in a priority queue. More...

int	Ntr_HeapExtractMin (NtrHeap heap, void item, int *key)
	Extracts the element with the minimum key from a priority queue. More...

int	Ntr_HeapCount (NtrHeap *heap)
	Returns the number of items in a priority queue. More...

NtrHeap *	Ntr_HeapClone (NtrHeap *source)
	Clones a priority queue. More...

void	Ntr_HeapForeach (NtrHeap heap, void(f)(void e, void arg), void *arg)
	Calls a function on all items in a heap.

int	Ntr_TestHeap (NtrHeap *heap, int i)
	Tests the heap property of a priority queue. More...

static void	ntrHeapify (NtrHeap *heap, int i)
	Maintains the heap property of a priority queue. More...

static int	ntrHeapResize (NtrHeap *heap)
	Resizes a priority queue. More...

Detailed Description

Functions for heap-based priority queues.

The functions in this file manage a priority queue implemented as a heap. The first element of the heap is the one with the smallest key. The queue stores generic pointers, but the key must be an int. Refer to Chapter 7 of Cormen, Leiserson, and Rivest for the theory.

Author: Fabio Somenzi

Copyright

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 University of Colorado 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 THE COPYRIGHT OWNER OR CONTRIBUTORS 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.

Function Documentation

◆ Ntr_FreeHeap()

void Ntr_FreeHeap ( NtrHeap * heap )

Frees a priority queue.

Side effects None

See also: Ntr_InitHeap

◆ Ntr_HeapClone()

NtrHeap* Ntr_HeapClone ( NtrHeap * source )

Clones a priority queue.

Side effects None

See also: Ntr_InitHeap

◆ Ntr_HeapCount()

int Ntr_HeapCount ( NtrHeap * heap )

Returns the number of items in a priority queue.

Side effects None

◆ Ntr_HeapExtractMin()

int Ntr_HeapExtractMin	(	NtrHeap *	heap,
		void *	item,
		int *	key
	)

Extracts the element with the minimum key from a priority queue.

Returns: 1 if successful; 0 otherwise.

Side effects The minimum key and the associated item are returned as: side effects.

See also: Ntr_HeapInsert

◆ Ntr_HeapInsert()

int Ntr_HeapInsert	(	NtrHeap *	heap,
		void *	item,
		int	key
	)

Inserts an item in a priority queue.

Returns: 1 if successful; 0 otherwise.

Side effects None

See also: Ntr_HeapExtractMin

◆ Ntr_InitHeap()

NtrHeap* Ntr_InitHeap ( int size )

Initializes a priority queue.

Returns: a pointer to the heap if successful; NULL otherwise.

Side effects None

See also: Ntr_FreeHeap

◆ Ntr_TestHeap()

int Ntr_TestHeap	(	NtrHeap *	heap,
		int	i
	)

Tests the heap property of a priority queue.

Returns: 1 if Successful; 0 otherwise.

Side effects None

◆ ntrHeapify()

static void ntrHeapify	(	NtrHeap *	heap,
		int	i
	)

static

Maintains the heap property of a priority queue.

Side effects None

See also: Ntr_HeapExtractMin

◆ ntrHeapResize()

static int ntrHeapResize ( NtrHeap * heap )