Bittilista

#include<iostream>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<queue>
#include<algorithm>
#include<cmath>
#include<utility>

using namespace std;

int main(void) {
  int64_t n, k;
  cin >> n >> k;
  k--;

  if(n == 1) {
    if(k == 0) cout << 0;
    else cout << 1;
    return 0;
  }

  if(k < ((int64_t)1 << (n-2))) {
    cout << 0;
    vector<int64_t> bits;
    for(int64_t i=0;i<n-2;i++) {
      bits.push_back(k%2);
      k/=2;
    }
    for(int64_t i=0;i<n-2;i++) {
      cout << bits[bits.size()-1-i];
    }
    cout << 0 << endl;
  } else {
    cout << 1;
    vector<int64_t> bits;
    for(int64_t i=0;i<n-2;i++) {
      bits.push_back(k%2);
      k/=2;
    }
    for(int64_t i=0;i<n-2;i++) {
      cout << bits[bits.size()-1-i];
    }
    cout << 1 << endl;
  }
  return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED