Submission #232179

#	Time	Username	Problem	Language	Result	Execution time	Memory
232179		PanTkd	Rack (eJOI19_rack)	C++14	40 / 100	15 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[1000006];
ll reverse(ll num,ll n)
{
    ll b=0;
    for (ll i = 0; i <= n-1; i++){
        if((din[i]&num)==din[i]){
            b+=(din[n-i-1]);
            if(b>MOD){
                b-=MOD;
            }
            //b%=MOD;
        }
    }
    return b;
}
int main() {
    
    ll n,k;cin>>n>>k;
    din[0]=1;
    for(ll i=1;i<1000006;i++){
        din[i]=(din[i-1]*2)%MOD;
    }
    cout<<(reverse(k-1, n)+1)%MOD<<endl;
    return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 0 / 60