堆排序

#include <stdio.h>
#define maxn 100000
int heap[maxn];
void shiftdown(int i, int n)
{
	int k, t;
	t=heap[i]; k=i<<1;
	while(k<=n)
	{
		if(k<n&&heap[k]>heap[k+1])k++;
		if(t>heap[k]){heap[i]=heap[k];i=k;k=i<<1;}
		else break;
	}
	heap[i]=t;
}
int main()
{
	int n;
	scanf("%d", &n);
	for(int i=1; i<=n; i++)	scanf("%d", &heap[i]);
	for(int i=n>>1; i; i--)	shiftdown(i, n);
	while(n)
	{
		printf("%d ", heap[1]);
		heap[1]=heap[n--];
		shiftdown(1, n);
	}
}