Hello everyone!

I was trying to solve this problem using hash struct, the complexity of my solution is O(N) which should pass the testings, but the judgment was giving me TLE, and after hours of trying to fix the problem, I decided to remove struct hash and instead of it, build the hash in the main, and Surprisingly it passed the testings!

this is my hash struct:

struct Hash
{
    int n,Base,Mod,Inv;
    vector <int> Po,iPo,Pre;
    Hash(string &s,int base,int mod)
    {
        Mod=mod;
        Base=base;
        Po.pb(1);
        iPo.pb(1);
        Pre.pb(0);
        Inv=inv(base,Mod);
        for(int i=1; i<=(int)s.size(); i++)
            Add(s[i-1]);
    }
    void Add(char c)
    {
        Po.pb(mul(Base,Po.back(),Mod));
        iPo.pb(mul(Inv,iPo.back(),Mod));
        Pre.pb(sum(Pre.back(),mul(c,Po.back(),Mod),Mod));
    }
    int G(int L,int R)
    {
        R++;
        int g=sub(Pre[R],Pre[L],Mod);
        return mul(iPo[L+1],g,Mod);
    }
};

and this is the first submission which was giving TLE and this the accepted submission

you can compare between them and notice that is exactly no difference except replacing the struct with normal code. so the question is, is using struct time consuming ?