题解

#include <iostream>
using namespace std;
typedef unsigned long long ull;
ull n, k;
void f(ull n, ull k) {
if(n==1) {
cout<<k;
return;
}
ull mid = (1UL<<(n-1))-1;
if(k<=mid) {
cout<<0;
f(n-1, k);
} else {
cout<<1;
f(n-1, mid-k+mid+1);
}
}
int main() {
cin>>n>>k;
f(n, k);
cout<<endl;
return 0;
}