Submission #446697

#	Time	Username	Problem	Language	Result	Execution time	Memory
446697		Khizri	Rack (eJOI19_rack)	C++17	100 / 100	28 ms	23160 KiB

rack

#include <bits/stdc++.h>
using namespace std;
//------------------------------DEFINE------------------------------
//******************************************************************
#define IOS ios_base::sync_with_stdio(false); cin.tie(0),cout.tie(0)
#define ll long long
#define pb push_back		 
#define F first																 
#define S second 															 
#define INF 1e18
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define pii pair<int,int>
#define pll pair<ll,ll>
#define OK cout<<"Ok"<<endl;
#define MOD (ll)(1e9+7)
#define endl "\n"
//******************************************************************
//----------------------------FUNCTION------------------------------
//******************************************************************
ll gcd(ll a,ll b){
	if(a>b) swap(a,b);
	if(a==0) return a+b;
	return gcd(b%a,a);
}
ll lcm(ll a,ll b){
	return a/gcd(a,b)*b;
}
bool is_prime(ll n){
	ll k=sqrt(n);
	if(n==2) return true;
	if(n<2||n%2==0||k*k==n) return false;
	for(int i=3;i<=k;i+=2){
		if(n%i==0){
			return false;
		}
	}
	return true;
}
//*****************************************************************
//--------------------------MAIN-CODE------------------------------
const int mxn=1e6+5;
ll t=1,n,k,p[mxn];
ll funk(ll n,ll k){
	if(n==0){
		if(k%2==0){
			return 2;
		}
		else{
			return 1;
		}
	}
	if(k%2==0){
		return (p[n]+funk(n-1,k/2))%MOD;
	}
	else{
		return funk(n-1,(k+1)/2)%MOD;
	}
}
void solve(){
	cin>>n>>k;
	p[0]=1;
	for(int i=1;i<=n;i++){
		p[i]=(p[i-1]*2)%MOD;
	}
	cout<<funk(n-1,k)<<endl;
}
int main(){
	IOS;
	//cin>>t;
	while(t--){
		solve();
	}
	return 0;
}

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