Submission #1268233

#	Time	Username	Problem	Language	Result	Execution time	Memory
1268233		axleofapulley	Rack (eJOI19_rack)	C++20	40 / 100	0 ms	328 KiB

rack

#include<bits/stdc++.h>
using namespace std;
int binexp(long long a){
    if(a==0) return 1;
    if(a==1) return 2;
    if(a&1) return (2*binexp(a/2)*binexp(a/2))%1000000007;
    return (binexp(a/2)*binexp(a/2))%1000000007;
}
int main(){
    long long n, k; cin >> n >> k; int sol[n]; for(int i = 0; i < n; i++) sol[i]=0; int ans = 1; 
    for(int i = 0; i < min(n,18ll); i++){
        if((k-1)%binexp(i+1)>=binexp(i)) sol[i]=1;
    }
    for(int i = 0; i < min(n,18ll); i++){
        ans=(ans+sol[i]*binexp(n-i-1))%1000000007;
    }
    cout << ans;
}

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 0 / 60