TOPC pH C++進制轉換解

#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
using ll=long long;
template<typename T> using V=vector<T>;
constexpr ll base=6ll*6*6*6*6*6*6*6*6*6*6*6;
constexpr ll N=1000000000;
static inline void solve(){
    string str;cin>>str;
    if(str=="0"){
        cout<<1<<endl;
        return;
    }
    V<ll> num;
    while(str.size()>=9){
        num.emplace_back(atoll(str.substr(str.size()-9).data()));
        str.resize(str.size()-9);
    }
    if(str.size())
        num.emplace_back(atoll(str.data()));
    reverse(num.begin(),num.end());
    V<ll> res{0};
    for(auto& x:num){
        ll cur=x;
        for(auto& i:res)
            cur+=i*N,i=cur%base,cur/=base;
        if(cur)
            res.emplace_back(cur);
    }
    int ans=12*(res.size()-1);
    while(res.back()>0)
        ans++,res.back()/=6;
    cout<<ans<<endl;
}
signed main(){
    int T=1;
    //cin>>T;
    while(T--)
        solve();
    return 0;
}