麻烦各位大佬看看，我的代码样例3没有过，但是测试点都AC了，这是怎么回事？

谢谢

#include<cstdio>
using namespace std;

int n;
unsigned long long k;

int main()
{
	scanf("%d%lu",&n,&k); 
	unsigned long long jie;
	for(int i=n-1;i>=0;i--)
	{
		jie=k/((unsigned long long)1<<i);
		printf("%lu",jie);
		k=k%((unsigned long long)1<<i);
		if(jie==1) k=((unsigned long long)1<<i)-k-1;
	}
	return 0;
}