Submission #607272

#	Time	Username	Problem	Language	Result	Execution time	Memory
607272		xtk	Rack (eJOI19_rack)	C++17	40 / 100	1 ms	308 KiB

rack

#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast")
// #define int long long
#define fi first
#define se second
#define pb push_back
#define mp make_pair
const long long MOD=1e9+7;
int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	long long n, k;
	cin>>n>>k;
	k--;
	long long ans=1;
	for (int i=1; i<=n; ++i) {
		if(k%2==1) {
			ans = (long long)(ans*2+1LL);
			ans = ans % MOD;
		}
		else {
			ans = (long long)(ans*2);
			ans = ans % MOD;
		}
		k/=2;
	}
	long long pow=1;
	for (int i=1; i<=n; ++i) {
		pow = (long long)(pow*2)%MOD;
	}
	pow--;
	cout<<(long long)(ans-pow)<<'\n';
}

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