Submission #256364

#	Time	Username	Problem	Language	Result	Execution time	Memory
256364		tomsyd	Rack (eJOI19_rack)	C++17	100 / 100	10 ms	7936 KiB

rack

#include <bits/stdc++.h>
#define int long long
using namespace std;

const int mod = 1e9+7;

int32_t main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	int n,k;
	cin >> n >> k;
	vector<int> pow2(n);
	pow2[0] = 1;
	for (int i=1; i<n; ++i){
		pow2[i] = (pow2[i-1]*2)%mod;
	}
	int ans = 0;
	for (int i=n-1; i>=0; --i){
		if (k%2 == 0) ans = (ans+pow2[i])%mod;
		k = (k+1)>>1;
	}
	cout << ans+1;
	return 0;
}

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