Submission #369909

#	Time	Username	Problem	Language	Result	Execution time	Memory
369909		AdamGS	Rack (eJOI19_rack)	C++14	100 / 100	10 ms	8172 KiB

rack

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(a, b) for(ll a = 0; a < (b); ++a)
const ll MOD=1e9+7, LIM=1e6+7;
ll pot[LIM];
int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    pot[0]=1;
    rep(i, LIM-1) pot[i+1]=(pot[i]*2)%MOD;
    ll n, k, ans=0;
    cin >> n >> k; --k;
    for(ll i=n-1; i>=0; --i) {
        if(k&1) ans=(ans+pot[i])%MOD;
        k>>=1;
    }
    cout << ans+1 << '\n';
}

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