Submission #993515

#	Time	Username	Problem	Language	Result	Execution time	Memory
993515		lazar3141	Rack (eJOI19_rack)	C++14	100 / 100	6 ms	8300 KiB

rack

#include<bits/stdc++.h>

using namespace std;

#define int long long

int md = 1e9+7;

void solve(){
    int n, k;cin>>n>>k;
    vector<int> v(1e6+10);
    v[0] = 1;
    for(int i = 1;i<1e6+10;i++) v[i] = (v[i-1]*2)%md;
    int ans = 0;
    while(k>1){
        if(k%2==0) ans+=v[n-1];
        ans%=md;
        k = (k+1)/2;
        n--;
    }
    ans++;
    ans%=md;
    cout<<ans<<endl;
}

int32_t main(){
    cin.tie(0);
    cout.tie(0);
    ios_base::sync_with_stdio(false);
    int t = 1;
    //cin>>t;
    while(t--){
        solve();
    }
    return 0;
}

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