算法之堆的实现

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头文件 Heap.c

#ifndef _HEAP_H_#define _HEAP_H_#include <stdio.h>#include "time.h"#include "stdlib.h"#include "ASSERT.h"#include "arithmetic.h"typedef struct{    int *data;    int heapMaxIndex;    int count;}Heap;    void swap(int *first,int *last);    Heap maxHeap(Heap heap,int capacity);    void maxHeapifyArr(Heap *heap,int arr[],int capacity);    Heap heapInsert(Heap heap,int item);    int heapSize(Heap heap);    int heapExtractMax(Heap *heap);#endif

c代码 Heap.c

#include "Heap.h"/**********************************************函数名：堆的实现*********************************************///根据对的容量生成一个最大堆Heap maxHeap(Heap heap,int capacity){    heap.heapMaxIndex = capacity;    heap.count = 0;    heap.data = (int *)malloc(sizeof(int)*(capacity+1));//根据heap的容量为指针分配内存空间    return heap;}//返回堆的大小int heapSize(Heap heap){    return heap.count;}//判断堆是否为空int heapIsEmpty(Heap heap){    return heap.count == 0;}Heap heapShiftUp(Heap heap,int k){    //将插入的元素与父元素比较大小，如果小则交换位置    while( k > 1 && *(heap.data+k/2) < *(heap.data+k) ){        swap((heap.data+k/2),(heap.data+k));        k /= 2;    }    return heap;}//向堆中插入元素Heap heapInsert(Heap heap,int item){    if(heap.count + 1 <= heap.heapMaxIndex){       *(heap.data+heap.count +1) = item;        heap.count ++;        return(heapShiftUp(heap,heap.count));    }    else{        return heap;    }}void heapShiftDown(Heap *heap,int k){    while(2*k <= heap->count){      //判断下左枝是否存在        int j = 2*k;                //在此循环中，data[k]和data[j]交换        if(j+1 <= heap->count){     //判断下右枝是否存在            if(*(heap->data+j+1) > *(heap->data+j)){                j += 1;            }        }        if(*(heap->data+k) >= *(heap->data+j))            break;        swap(heap->data+k,heap->data+j);        k = j;    }}//取出堆中最大的元素int heapExtractMax(Heap *heap){    assert(heap->count > 0);    int max = *(heap->data + 1);;    swap((heap->data+1),(heap->data+heap->count));    heap->count --;    heapShiftDown(heap,1);    return max;}//释放为堆中为指针分配的空间void heapFree(Heap heap){    free(heap.data);}//Heapify算法将数组插入到堆中void maxHeapifyArr(Heap *heap,int arr[],int capacity){    heap->heapMaxIndex = capacity;    heap->data = (int *)malloc(sizeof(int)*(capacity+1));    int i;    for(i=0;i<capacity;i++){        *(heap->data+i+1) = arr[i];    }    heap->count = capacity;    for(i=heap->count/2;i>=1;i--){        heapShiftDown(heap,i);    }}/**********************************************函数名：原地堆排序，不占用空间*********************************************/void __shiftDown(int arr[],int n,int k){    while(2*k+1 < n){        int j = 2*k+1;        if(j+1 < n && arr[j+1] > arr[j]){            j += 1;        }        if(arr[k] >= arr[k])            break;        swap(&arr[k],&arr[j]);        k=j;    }}void heapSort(int arr[],int n){    int i;    //heapfiy，将数组使用heapfiy进行排序    for(i=(n-1)/2;i>=0;i--){        __shiftDown(arr,n,i);    }    for(i=n-1;i>0;i--){        //将第一个元素放到末尾，把其他的元素进行最大堆排序        swap(&arr[0],&arr[i]);        __shiftDown(arr,i,0);    }}

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