Submission #289262

#	Time	Username	Problem	Language	Result	Execution time	Memory
289262		FulopMate	Rack (eJOI19_rack)	C++14	100 / 100	135 ms	256 KiB

rack

#include <bits/stdc++.h>

using namespace std;

#define ll long long
ll mod = 1e9+7;

ll pow2(int x){
    ll r = 1;
    for(int i = 0; i < x; i++){
        r *= 2;
        r %= mod;
    }
    return r;
}

int main(){
    ll n, k; cin>>n>>k;
    ll r = 0;
    while(n > 1){
        if(k%2 == 0){
            r += pow2(n-1);
            r %= mod;
        }
        k = (k+1)/2;
        n--;
    }
    if(k == 2)r++;
    cout<<r+1;
    return 0;
}

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