堆的实现

来源：互联网发布：在到处之间找我知乎编辑：程序博客网时间：2024/06/03 23:39

1.堆是一棵完全二叉树，堆有两个性质，即结构性和堆序性，堆序性指的是，对于每个结点X，它的父亲中的关键字小于或等于X的关键字。

2.完全二叉树很有规律，它可以用一个数组表示而不需要指针，对于数组中任意一个位置i上的元素，其左儿子在位置2i上，右儿子在2i+1上，它的父亲则在i/2位置上。

具体的代码实现如下：

////  Heap.h//  Heap////  Created by Mac on 15/12/6.//  Copyright © 2015年 Mac. All rights reserved.//#ifndef Heap_h#define Heap_h#include <stdio.h>#include <stdlib.h>#include <stdbool.h>typedef struct _tagHeap{    int capacity;    int size;    int * data;}Heap;//createHeap* HeapCreate(int size);//insertint HeapInsert(Heap* h ,int data);//del minint HeapDelMin(Heap* h);//destroyvoid HeapDestroy(Heap* h);#endif /* Heap_h */

////  Heap.c//  Heap////  Created by Mac on 15/12/6.//  Copyright © 2015年 Mac. All rights reserved.//#include "Heap.h"#define MIN_DATA  -9999999999//creat 二叉堆//类似于完全二叉树Heap* HeapCreate(int size){    Heap* h = (Heap*)malloc(sizeof(Heap));    if (h == NULL) {        return NULL;    }    memset(h,0,sizeof(Heap));        h->capacity = size;    h->data = (int*)malloc((size+1)*sizeof(int));    if (h->data == NULL) {        return NULL;    }    memset(h->data,0,(size+1)*sizeof(int));   //0 is pre    h->data[0] = MIN_DATA;    return h;}static bool HeapIsFull(Heap* h){    if (h == NULL) {        return true;    }        return h->size == h->capacity;}static bool HeapIsEmpty(Heap* h){    if (h == NULL) {        return true;    }        return h->size == 0;}//insert  root i   left 2*i  right 2*i+1//要保持堆序性int HeapInsert(Heap* h ,int data){    if (HeapIsFull(h)) {        return -1;    }    int i = 0;    for (i = ++h->size; h->data[i/2] > data; i /=2) {  //上滤        h->data[i] = h->data[i/2];    }    h->data[i] = data;        return 0;}//del minint HeapDelMin(Heap* h){    if (HeapIsEmpty(h)) {        return h->data[0];    }        int child = 0;    int minData = h->data[1];    int lastData = h->data[h->size--];        int i = 0;        for (i = 1; 2*i <= h->size; i = child) {        child = (i << 1); // i*2;                //find smaller child in left and right        if (child != h->size && h->data[child+1] < h->data[child]) {            child++;        }                if (h->data[child] < lastData) {            h->data[i] = h->data[child];   //下滤        }        else{            break;        }    }    h->data[i] = lastData;        return minData;}//destroyvoid HeapDestroy(Heap* h){    if (h == NULL) {        return;    }        free(h->data);    h->data = NULL;        free(h);    h = NULL;}

////  main.c//  Heap////  Created by Mac on 15/12/6.//  Copyright © 2015年 Mac. All rights reserved.//#include <stdio.h>#include "Heap.h"int main(int argc, const char * argv[]) {    // insert code here...        Heap* h = HeapCreate(100);        HeapInsert(h, 1);    HeapInsert(h, 2);    HeapInsert(h, 3);    HeapInsert(h, -1);        printf("%d\n",HeapDelMin(h));    printf("%d\n",HeapDelMin(h));        printf("%d\n",h->data[1]);    printf("%d\n",h->data[2]);    printf("%d\n",h->data[3]);    //    printf("%d\n",h->size);//    printf("%d\n",h->data[h->size--]);//    printf("%d\n",h->data[4]);        HeapDestroy(h);        return 0;}

0 0