Submission #232196

#	Time	Username	Problem	Language	Result	Execution time	Memory
232196		PanTkd	Rack (eJOI19_rack)	C++14	100 / 100	14 ms	8192 KiB

rack

//
//  main.cpp
//  Hanging Rack
//
//  Created by Panagiotis Hadjicostas on 16/05/2020.
//  Copyright © 2020 Panagiotis Hadjicostas. All rights reserved.
//

#include <bits/stdc++.h>
using namespace std;
typedef unsigned long long ll;
#define MOD ll(1e9+7)
ll din[1000001];
ll reverse1(ll num,ll n)
{
    ll b=0;
    for (ll i = n - 1; i >= 0&&num; i--) {
        if (num % 2 == 1) {
            b=(b+din[i])%MOD;
            //cout<<b<<endl;
        }
        num/=2;
    }
    return b;
}
int main() {
    
    ll n,k;cin>>n>>k;
    din[0]=1;
    for(ll i=1;i<1000001;i++){
        din[i]=(din[i-1]*2)%MOD;
    }
    //cout<<'h';
    //k--;
    cout<<(reverse1(k-1, n)+1)%MOD<<endl;
    return 0;
}

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