Submission #999795

#	Time	Username	Problem	Language	Result	Execution time	Memory
999795		vjudge1	Rack (eJOI19_rack)	C++17	100 / 100	0 ms	348 KiB

rack

#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define ll long long
const ll sz=2e5+5, mod=1e9+7;
ll power(ll a, ll b)
{
    if(b==0) return 1;
    ll temp=power(a, b/2);
    if(b%2==0){
        return temp%mod*temp%mod;
    }
    return (temp%mod*temp%mod*a)%mod;
}
int main()
{
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    ll n, k;
    cin>>n>>k;
    ll j=n-1, ans=0;
    //cout<<power(2, 3)<<' ';
    if(k==1){
        cout<<1;
        return 0;
    }
    while(k>1){
        if(k%2==0){
            ans+=power(2, j);
            ans%=mod;
        }
        k=(k+1)/2;
        j--;
    }
    cout<<ans+1;
}

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