Submission #969124

#	Time	Username	Problem	Language	Result	Execution time	Memory
969124		12345678	Rack (eJOI19_rack)	C++17	100 / 100	7 ms	8284 KiB

rack

#include <bits/stdc++.h>

using namespace std;

#define ll long long

const int nx=1e6+5, mod=1e9+7;

ll n, k, res, p[nx];

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    p[0]=1;
    for (int i=1; i<nx; i++) p[i]=(p[i-1]*2)%mod;
    cin>>n>>k;
    for (int i=n-1; i>=0; i--)
    {
        if (k%2==0) res=(res+p[i])%mod;
        k=(k+1)/2;
    }
    cout<<(res+k)%mod;
}

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