Submission #742092

#	Time	Username	Problem	Language	Result	Execution time	Memory
742092		bogdanvladmihai	Rack (eJOI19_rack)	C++14	100 / 100	6 ms	4008 KiB

rack

#include <iostream>
#include <vector>

const int M = 1e9 + 7;

int main() {
    int N;
    int64_t K;
    std::cin >> N >> K;
    K--;
    std::vector<int> pow(N + 1, 1);
    for (size_t i = 1; i < pow.size(); i++) {
        pow[i] = pow[i - 1] + pow[i - 1];
        if (pow[i] >= M) {
            pow[i] -= M;
        }
    }
    int answer = 1;
    for (int i = 0; i < 63; i++) {
        if ((K & (1LL << (int64_t)i)) > 0) {
            answer += pow[N - i - 1];
            if (answer >= M) {
                answer -= M;
            }
        }
    }
    std::cout << answer << "\n";
    return 0;
}

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