제출 #607268

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
607268		xtk	Rack (eJOI19_rack)	C++17	40 / 100	2 ms	312 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 int MAXN=1e6+7;
const int MOD=1e9+7;
long long szybkie_potowanie(long long a, long long n) {
	long long w = 1;
	while (n>0) {
		if (n%2==1) {
			w=(w*a)%MOD;
		}
		a = (a*a)%MOD;
		n/=2;
	}
	return w;
}
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 = szybkie_potowanie(2, n)-1LL; 
	cout<<(long long)ans-pow<<'\n';
}

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