堆的介绍与调整

本文主要是实现动态的创建一个堆，并且动态地向堆中插入元素，以及删除堆顶元素。

堆的创建与删除操作分为大根堆与小根堆两种实现。

头文件

#include

#include

#include

#include

#include

数据结构

typedef struct

{

uint32_t cursize;

uint32_t maxsize;

uint32_t *element;

}heap_t;

typedef enum

{

false,

true

}bool;

公共方法

/*申请堆，入参为堆中元素的个数*/

heap_t *heap_malloc(uint32_t size)

{

heap_t * heap = NULL;

uint32_t *data = NULL;

heap = (heap_t*)malloc(sizeof(heap_t));

if(NULL == heap)

{

return NULL;

}

memset(heap, 0x0, sizeof(heap_t));

data = (uint32_t*)malloc(sizeof(uint32_t)*size);

memset(data, 0x0, sizeof(uint32_t)*size);

if(NULL == data)

{

free(heap);

heap = NULL;

return NULL;

}

heap->cursize = 0;

heap->maxsize = size;

heap->element = data;

return heap;

}

/*释放堆所占用的资源*/

void heap_free(heap_t *heap)

{

free(heap->element);

heap->element = NULL;

free(heap);

heap = NULL;

}

/*判断堆是否已满*/

bool heap_full(heap_t *heap)

{

if(heap->cursize >= heap->maxsize)

return true;

else

return false;

}

/*判断堆是否为空*/

bool heap_empty(heap_t *heap)

{

if(heap->cursize == 0)

return true;

else

return false;

}

/*按顺序输出堆元素*/

void heap_out(heap_t *heap)

{

int i = 0;

for(i=0; i < heap->cursize; i++)

{

printf("%d\t",heap->element[i]);

}

printf("\n");

}

小根堆

/*向堆中插入一个元素*/

void heap_insert(heap_t *heap, uint32_t elem)

{

int i = 0;

if(heap_full(heap))

{

printf("heap is full, insert failed.\n");

return;

}

for(i = heap->cursize; heap->element[i/2] > elem; i /=2)

{

heap->element[i] = heap->element[i/2];

}

heap->element[i] = elem;

heap->cursize++;

return;

}

/*删除根节点*/

void heap_delete(heap_t *heap)

{

int i = 0, child = 0;

uint32_t minelem = 0, lastelem = 0;

if(heap_empty(heap))

{

printf("heap is empty, delete failed.\n");

return;

}

minelem = heap->element[0];

lastelem = heap->element[heap->cursize-1];

for(i = 0; i*2 < heap->cursize; i = child)

{

child = i*2 + 1;

if(child != heap->cursize && heap->element[child+1] < heap->element[child])

child++;

if(lastelem > heap->element[child])

heap->element[i] = heap->element[child];

else

break;

}

heap->element[i] = lastelem;

heap->cursize--;

return;

}

测试程序

int main(int argc, char *argv[])

{

int i = 0;

heap_t *heap = heap_malloc(20);

if(heap == NULL)

return 0;

for(i = 0; i < 10; i++)

{

heap_insert(heap, i);

}

heap_insert(heap, 5);

heap_out(heap);

heap_free(heap);

return 0;

}

测试结果

[[email protected] heap]# ./test

0 1 2 3 4 5 6 7 8 9 5

大根堆

原文：http://blog.csdn.net/pngynghay/article/details/22101359