堆排序

思想：假设数组放入完全二叉树中，

1、初始化堆：调节父结点与子结点的大小。让所有的子结点都小于父结点。

2、将完全二叉树中的叶子结点和根结点进行互换后，继续调整堆。直至结束

#include<iostream>
#include<stdio.h>
#include<stdlib.h>
#include<random>
#include<time.h>
#include<sys/timeb.h>
using namespace std;
#define MAX 9long getSystemTime()
{struct timeb tb;ftime(&tb);return tb.time * 1000 + tb.millitm;  //毫秒
}void printArr(int arr[], int length)
{for (int i = 0; i < length; i++){printf("%d ", arr[i]);}printf("\n");
}
void swapElementme(int* a, int* b)
{int temp =*a;*a = *b;*b = temp;
}//堆排序
void heapSortme(int arr[], int length)
{int mid = length / 2 - 1;int lchild = mid * 2 + 1;int rchild = mid * 2 + 2;int max = mid;//初始化堆for (int i = mid; i < length; i--)  {if (arr[i] < arr[lchild]){max = lchild;}if (arr[mid] > arr[rchild]){max = rchild;}if (max != mid){swapElementme(&arr[mid], &arr[max]);}}for (int i = 0; i < length; i++){swapElementme(&arr[0], &arr[length - 1]);heapSortme(arr, length);}
}void swapElement(int arr[], int a, int b)
{int temp = arr[a];arr[a] = arr[b];arr[b] = temp;
}
/*@param arr 待调整的数组@param index 待调整的结点的下标@param length 数组长度
*/
void heapAdjust(int arr[],int index, int length)
{//保存当前结点的下标int max = index;//保存右孩子的数组下标int lchild = index * 2 + 1;//保存左孩子的数组下标int rchild = index * 2 + 2;if (lchild<length && arr[lchild]>arr[max]){max = lchild;}if (rchild<length && arr[rchild]>arr[max]){max = rchild;}if (max != index){//交换两个结点swapElement(arr, max, index);heapAdjust(arr, max, length);}}
void heapSort(int arr[], int length)
{//初始化堆for (int i = length/2-1; i >=0; i--){heapAdjust(arr, i, length);}//交换堆顶元素和最后一个元素for (int i = length-1; i >= 0; i--){swapElement(arr, 0,i);heapAdjust(arr, 0, i);}
}int main()
{int arr[] = { 4,2,8,0,5,7,1,3,9};long t_start = getSystemTime();printArr(arr,MAX);heapSort(arr,MAX);printArr(arr, MAX);long t_end = getSystemTime();printf("堆排序%d个元素，所需时间：%1d\n", MAX, t_end - t_start);system("pause");return 0;
}

运行结果：