제출 #1198588

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1198588		SzymonKrzywda	Rack (eJOI19_rack)	C++20	100 / 100	0 ms	328 KiB

rack

#include <iostream>

using ll  =long long;

using namespace std;

const ll MOD = 1e9 + 7;


ll fastP(ll a, ll p){
    if (p == 0) return 1;

    if (p % 2 == 0){
        ll w = fastP(a, p / 2);
        return (w * w) % MOD;
    }
    else{
        return (fastP(a, p - 1) * a) % MOD;
    }
}



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


    ll n, k;

    cin >> n >> k;
    k--;


    ll wynik = 0;

    for (ll i = 63; i >= 0; i--){
        if (k & (1LL << i)){
            //cout << k << ' ' << i  <<  ' ' << (1LL << i)  << ' ' << (n - i - 1) << ' ' <<  fastP(2, (n - i - 1)) << '\n';
            wynik += fastP(2, (n - i - 1));
            wynik %= MOD;
        }

    }

    //1 0 0 1 0


    cout << (wynik + 1) % MOD << '\n';


    return 0;
}

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