Submission #432385

#	Time	Username	Problem	Language	Result	Execution time	Memory
432385		Dakto	Rack (eJOI19_rack)	C++17	100 / 100	45 ms	30748 KiB

rack

#include <bits/stdc++.h>

using namespace std;

const long long mod=1e9+7;

long long solve(long long n, long long k){
    if(n==0) return 0;
    if(log2(k)<=n-1) return (2*solve(n-1,k))%mod;
    else return (2*solve(n-1, k-(1ll<<(n-1)))+1)%mod;
}

int main(){
    long long n,k;
    cin>>n>>k;
    cout<<(solve(n,k)+1)%mod<<endl;
}

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