Submission #1097238

#	Time	Username	Problem	Language	Result	Execution time	Memory
1097238		vjudge1	Rack (eJOI19_rack)	C++11	100 / 100	4 ms	584 KiB

rack

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll MOD = 1e9 + 7;
bitset<(size_t)1e6> bin;
ll solve(const int &n, ll k) {
    if (n == 1) {
        return k;
    }
    bin.reset();
    --k;
    for (int i = n - 1; i >= 0 && k; --i) {
        if (k&1) {
            bin.set(i);
        }
        k /= 2;
    }
    ll ans = 1, base = 1;
    for (int i = 0; i < n; ++i) {
        ans = (ans + bin[i] * base)%MOD;
        base = (base * 2)%MOD;
    }
    return ans;
}
int main() {
    cin.sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    ll k;
    cin >> n >> k;
    cout << solve(n, k) << "\n";
    cout.flush();
    return EXIT_SUCCESS;
}

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