HDOJ1425 sort-快排水题

#include <cstdio>
#include <iostream>
#include <cstring>
#define MAXN 1000005
using namespace std;
int input[MAXN];
/*
 * 快速排序 
 */
void QuickSort(int a[],int left,int right){			//数组和上下界 
	if(!(left < right))					//递归结束条件 
		return;
	int key = a[left];					//轴值 
	int l,r;
	l = left;
	r = right;
	//一轮快排 
	while(l < r){
		while(l < r && a[r] >= key)
			r--;
		a[l] = a[r];
		while(l < r && a[l] <= key)
			l++;
		a[r] = a[l];
	}
	a[l] = key;
	//递归	
	QuickSort(a,left,l-1);
	QuickSort(a,l+1,right);
	
}
int main(){
	int n,m;			//接受输入
	while(scanf("%d%d",&n,&m) != EOF) {
		for(int i = 1;i <= n; i++)
			scanf("%d",&input[i]);
		QuickSort(input,1,n);
		for(int i = n;i > n - m;i--)
			if(i != n-m+1)
		 		printf("%d ",input[i]);
		 	else	
		 		printf("%d\n",input[i]);
	}
	 
	return 0;
}