Submission #1097534

#	Time	Username	Problem	Language	Result	Execution time	Memory
1097534		vjudge1	Rack (eJOI19_rack)	C++17	100 / 100	9 ms	8028 KiB

rack

#include<bits/stdc++.h>
using namespace std;
#define forsn(i,s,n) for(int i=int(s);i<int(n);i++)
#define forn(i,n) forsn(i,0,n)
#define dforsn(i,s,n) for(int i=int(n)-1;i>=int(s);i--)
#define dforn(i,n) dforsn(i,0,n)
#define sz(x) int(x.size())
#define all(x) begin(x),end(x)
#define pb push_back

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef pair<int,int> ii;

const int MOD=1e9+7;

int n;
vll pw;

ll solve(int lvl, ll cnt){
    if(lvl==n) return 1LL;
    if(cnt%2==1){
        return solve(lvl+1,(cnt+1)/2);
    }else{
        return (pw[n-1-lvl]+solve(lvl+1,cnt/2))%MOD;
    }
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
	
    ll k;
    cin>>n>>k;
    pw.resize(n+1);
    pw[0]=1;
    forn(i,n) pw[i+1]=pw[i]*2LL%MOD;
    cout<<solve(0,k)<<'\n';
    
    return 0;
}

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