Submission #1179295

#	Time	Username	Problem	Language	Result	Execution time	Memory
1179295		vladkonoval	Rack (eJOI19_rack)	C++20	40 / 100	1 ms	1936 KiB

rack

#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
using ll = long long;
ll n,k,a[1000007],res,i;
int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    cin>>n>>k;
    if (k==1){cout<<1;return 0;}
    a[1] = 1;
    res = (1<<(n-1))%1000000007;
    for (i=2;i<=(1<<n);i++) {
        if (i%2==0) a[i] = a[i-1]+res;
        else {
            a[i%1000000007] = (a[(i-1)/2+1]+1)/2;
        }
        a[i%1000000007]%=1000000007;
        if (a[i%1000000007]==k) {cout<<i;return 0;}
    }

    return 0;
}

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