Submission #448790

#	Time	Username	Problem	Language	Result	Execution time	Memory
448790		UltraFalcon	Rack (eJOI19_rack)	C++17	100 / 100	117 ms	316 KiB

rack

#include <bits/stdc++.h>
#define int long long

using namespace std;

int pow_mod(int b, int p, int m) {
    int r = 1;
    for (int i=0; i<p; i++) {
        r = (r*b) % m;
    }
    return r;
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    const int limit = (1e9) + 7;

    int n, k;
    cin >> n >> k;

    k--;
    int i = n-1;
    int r = 1;

    while (i >= 0) {
        if (k % 2 == 1) {
            //assert(i < 62);
            r = (r + pow_mod(2, i, limit)) % limit;
        }
        k /= 2;
        i--;
    }
    cout << r % limit << "\n";
}

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