Submission #841574

#	Time	Username	Problem	Language	Result	Execution time	Memory
841574		WLZ	Rack (eJOI19_rack)	C++17	100 / 100	8 ms	8028 KiB

rack

#include <bits/stdc++.h>
using namespace std;

const long long MOD = (long long) 1e9 + 7;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  long long k;
  cin >> n >> k;
  k--;
  vector<long long> pw(n);
  pw[0] = 1;
  for (int i = 1; i < n; i++) {
    pw[i] = (pw[i - 1] * 2) % MOD;
  }
  long long ans = 0;
  for (int i = n - 1; i >= 0; i--) {
    if (k % 2 == 1) {
      ans = (ans + pw[i]) % MOD;
    }
    k /= 2;
  }
  cout << ans + 1 << '\n';
  return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 60 / 60