Submission #675738

#	Time	Username	Problem	Language	Result	Execution time	Memory
675738		Alma	Rack (eJOI19_rack)	C++17	100 / 100	11 ms	7872 KiB

rack

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

using ll = long long;
ll MOD = 1e9+7;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);

    ll n, k;
    cin >> n >> k;
    ll pos = 1, add = n;

    vector<ll> powMOD(n+1);
    powMOD[0] = 1;
    for (int i = 1; i <= n; i++) {
        powMOD[i] = (powMOD[i-1] * 2) % MOD;
    }

    k--;
    for (int i = 0; i < n; i++) {
        add--;
        if (k % 2 == 1) {
            pos += powMOD[add];
            pos %= MOD;
        }
        k /= 2;
    }

    cout << pos << '\n';

    return 0;
}

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