代码

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

unsigned a[MAXN];

int Min(int x,int y){
return x<y? x: y;
}

int main() {
	fread(a, 1, MAXN * 4, stdin);
	int n = a[0];
	
	// Rearrange the ducks a[1] .. a[n] here
for (int i=17;i>=0;--i){
int m=(1<<i)-1;
if (m>=n) continue;
std::nth_element(a+1,a+m,a+Min(n+1,1<<i+1));
}

	fwrite(a + 1, 1, n * 4, stdout);
	return 0;
}

评测结果