代码

#include<stdio.h>
#include<algorithm>
#define MAXN 100001

unsigned a[MAXN];
int n;

int main() {
	fread(a, 1, MAXN * 4, stdin);
	n = a[0];int j;
	
	// Rearrange the ducks a[1] .. a[n] here
	for (int i=n;i>1;i=j)j=(i+1)>>1,std::nth_element(a, a+j, a+i);
	fwrite(a + 1, 1, n * 4, stdout);
	return 0;
}

评测结果