排序（5）——堆排序

“test.cpp”

<strong><span style="font-size:18px;">#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
using namespace std;
#include<assert.h>

void HeapAdjust(int* arr,int parent,size_t size)
{
assert(arr);
int child = 2*parent+1;

while(child && child < size)
{
if((child+1 < size) && (arr[child+1] > arr[child]))
{
++child;
}
if(arr[parent] < arr[child])
{
swap(arr[parent],arr[child]);
}
parent = child;
child = 2*parent+1;
}
}
void test()
{
int arr[] = {5,3,9,2,7,1,8,0,4,6};
size_t size = sizeof(arr)/sizeof(arr[0]);

//先建立一个大顶堆
for(int i = (size-2)/2;i >= 0;i--)
{
HeapAdjust(arr,i,size);
}

for(int i = 0;i < size;i++)
{
cout<<arr[i]<<" ";
}
cout<<endl;

//把根节点的值和最后一个节点的值进行交换，在从根节点开始向下调整
for(int i = size-1;i >= 0;i--)
{
swap(arr[0],arr[i]);
HeapAdjust(arr,0,i);
}
for(int i = 0;i < size;i++)
{
cout<<arr[i]<<" ";
}
cout<<endl;
}
int main()
{
test();
system("pause");
return 0;
}</span></strong>