제출 #731760

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
731760		AtabayRajabli	Rack (eJOI19_rack)	C++11	100 / 100	1 ms	320 KiB

rack

#include <bits/stdc++.h>
#define pb push_back
#define pii pair<int, int>
#define pll pair<ll, ll>
#define MAX 5e4 + 1
#define all(v) v.begin(), v.end()
#define sz(v) v.size()
#define INF 0x3F3F3F3F3F3F3F3FLL
#define OPT ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define sec second
#define fi first

typedef long long ll;
typedef unsigned long long ull;
using namespace std;

ll binpow(ll a, ll b, ll c)
{
    ll res = 1;
    a%=c;

    while(b > 0)
    {
        if(b & 1)
        {
            res = res * a % c;
        }
        a = a * a % c;
        b >>= 1;
    }

    return res;
}

void $()
{
    ll n, k, mod = 1e9 + 7;
    cin >> n >> k;
    k--;

    ll res = 1;

    while(k)
    {
        n--;
        if(k & 1)
        {
            res = (res + binpow(2, n, mod))%mod;
        }

        k >>= 1;
    }

    cout << res << endl;
}

int main()
{
    OPT

    int t = 1;

    while(t--)
        $();
}

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