Submission #696499

#	Time	Username	Problem	Language	Result	Execution time	Memory
696499		Hanksburger	Rack (eJOI19_rack)	C++17	100 / 100	7 ms	7892 KiB

rack

#include <bits/stdc++.h>
using namespace std;
const long long mod=1e9+7;
long long a[1000005];
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    long long n, k, ans=0;
    cin >> n >> k;
    a[0]=1;
    for (long long i=1; i<=n; i++)
        a[i]=a[i-1]*2%mod;
    for (long long i=0; i<=59; i++)
        if ((k-1)&(1LL<<i))
            ans=(ans+a[n-i-1])%mod;
    cout << (ans+1)%mod;
}

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