堆的动态创建与根节点删除

堆的介绍与调整

关于堆的介绍以及对于给定的完全二叉树，调整为大根堆或者小根堆，可以参考博文http://blog.csdn.net/pngynghay/article/details/22052737，在此不再赘述。

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 <stdio.h>#include <stdlib.h>#include <stdint.h>#include <assert.h>#include <string.h>

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;elsereturn false;    }/*判断堆是否为空*/bool heap_empty(heap_t *heap){if(heap->cursize == 0)return true;elsereturn 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 minheap_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; i > 0 && 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 minheap_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 + 1 < heap->cursize && heap->element[child+1] < heap->element[child])child++;if(child < heap->cursize && lastelem > heap->element[child])heap->element[i] = heap->element[child];elsebreak;}heap->element[i] = lastelem;heap->cursize--;return;}

大根堆

/*向堆中插入一个元素*/void maxheap_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; i > 0 && 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 maxheap_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 + 1 < heap->cursize  && heap->element[child+1] > heap->element[child])child++;if(child < heap->cursize && lastelem < heap->element[child])heap->element[i] = heap->element[child];elsebreak;}heap->element[i] = lastelem;heap->cursize--;return;}

测试程序

void minheaptest(){int i = 0;heap_t *heap = heap_malloc(20);if(heap == NULL)return;for(i = 0; i < 10; i++){minheap_insert(heap, i);}minheap_insert(heap, 5);minheap_delete(heap);heap_out(heap);heap_free(heap);}void maxheaptest(){int i = 0;heap_t *heap = heap_malloc(20);if(heap == NULL)return;for(i = 0; i < 10; i++){maxheap_insert(heap, i);}maxheap_insert(heap, 5);maxheap_delete(heap);heap_out(heap);heap_free(heap);}int main(int argc, char *argv[]){printf("\nmin heap test:\n");minheaptest();printf("\nmax heap test:\n");maxheaptest();return 0;}

测试结果