Hello,I know this question might be silly to most of you but I desparetly seeking the answer.Here is my question-

#include <bits/stdc++.h>

using namespace std;

long long BaseConversion(long long n,long long p)
{
    if(n<p)return n;
    return n%p + 10*BaseConversion(n/p,p);
}

int main() {
    long long n;
    while(cin>>n)
    {
    	cout<<BaseConversion(n,9)<<endl;
    }
    return 0;
}

How do I calculate complexity from this problem?As long as I know about complexity depends on loop. But in recursion how can I calculate this? The above code works in 0<=N<=10^18 range .How this code gives log(n) complexity?

Thanks.