算法导论笔记之----堆排序

#include<iostream>
using namespace std;
void Buildhead(int *arr,int parent,int longth)
{
int lagest;
if(parent*2+1<=longth)
{
for(;parent>=0;--parent)
{
lagest=parent*2+1;
if(lagest+1<=longth&&arr[lagest]<arr[lagest+1])
lagest++;
if(arr[parent]<arr[lagest])
{
swap(arr[parent],arr[lagest]);
Buildhead(arr,lagest,longth);
}
}
}
}
void B_sort(int *arr,int longth)
{
Buildhead(arr,(longth-1)/2,longth);//建立一个最大堆
for(int i=longth;i>0;)
{
swap(arr[i],arr[0]);
i--;
Buildhead(arr,(i-1)/2,i);
}
}
int main()
{
int T=0;
int *arr;
while(cin>>T,T)
{
arr=new int[T];
cout<<"please input "<<T<<"numbers: ";
for(int i=0;i<T;++i)
cin>>arr[i];
B_sort(arr,T-1);
for(int i=0;i<T;++i)
cout<<arr[i]<<" ";
cout<<endl;
delete arr;
}
return 0;
}