堆排序__算法导论实现

这个排序是算法导论上堆排序的实现，

#include<iostream>
#include<time.h>
using namespace std;

void max_heap(int data[],int i,int len)//对于左右子树已是最大堆的树，将整个树生成最大堆
{
int left=2*i+1;
 int right=left+1;
int large=i;

if(left<=len&&data[i]<data[left])
large=left;
else
large=i;

if(right<=len&&data[large]<data[right])
large=right;
if(large!=i)
{
int temp=data[i];
data[i]=data[large];
data[large]=temp;

max_heap(data,large,len);
}
}
void buildheap(int data[],int len)//将一个不是最大堆的树，建成最大堆
{
int i=0;

for(i=len/2;i>=0;i--)
max_heap(data,i,len);
}
void heapsort(int data[],int len)//堆排序
{
int temp,i;

buildheap(data,len);//建最大堆

for(i=len;i>=0;i--)
{
temp=data[0];//将最大值（顶点）与最后一个叶子结点交换
data[0]=data[i];
data[i]=temp;

max_heap(data,0,i-1);//重新生成最大堆
}
}

int main()
{
int data[100];
int i;
int len=10;
srand((unsigned int)(time(NULL)));

for(i=0;i<len;i++)
data[i]=rand();

cout<<"the data rand() are :"<<endl;
for(i=0;i<len;i++)
cout<<data[i]<<" ";
cout<<endl;

heapsort(data,len-1);
cout<<"after sort are :"<<endl;
for(i=0;i<len;i++)
cout<<data[i]<<" ";
cout<<endl;

return 0;
}