Submission #775549

#	Time	Username	Problem	Language	Result	Execution time	Memory
775549		vjudge1	Rack (eJOI19_rack)	C++17	100 / 100	8 ms	7924 KiB

rack

#include<bits/stdc++.h>
using namespace std;
#define lalala ios_base::sync_with_stdio(false);cin.tie(NULL);
#define endl "\n"
#define ll long long
#define pb push_back
#define mod 1000000007
 
int main(){
	lalala;
	ll int n,k;cin>>n>>k;
	ll int arr[n+1];
	arr[0]=1;
	for(int i=1;i<=n;i++){
		arr[i]=(arr[i-1]*(ll int)2)%mod;
	}
	ll int ans=0;
	for(int i=n-1;i>-1;i--){
		if(k%2==0){
			ans+=arr[i];
			ans%=mod;k/=2;
		}
		else k=k/2+1;
	}
	cout<<(ans+1)%mod<<endl;

}

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