Submission #760791

#	Time	Username	Problem	Language	Result	Execution time	Memory
760791		bachhoangxuan	Rack (eJOI19_rack)	C++17	100 / 100	2 ms	320 KiB

rack

#include <bits/stdc++.h>
using namespace std;
#define int long long 
const int mod=1e9+7;
int power(int a,int n){
    int res=1;
    while(n){
        if(n&1) res=res*a%mod;
        a=a*a%mod;n>>=1;
    }
    return res;
}
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n,x,ans=0;cin >> n >> x;
    for(int i=n-1;i>=0;i--){
        if(x%2==0){ans=(ans+power(2,i))%mod;x>>=1;}
        else x=x/2+1;
    }
    cout << ans+1 << '\n';
}

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