Light OJ 1258 / Hashing

/***
 created: 2022-01-02-01.09.39
***/

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define test int tt; cin>>tt; for(int cs=1;cs<=tt;cs++)
#define get_lost_idiot return 0
#define nl '\n'

ll mod[2]= {1000007707,1000007909};
ll base[2]= {149,307};
ll hash1[2][1000007];
ll hash2[2][1000007];
ll p1[1000007];
ll p2[1000007];


void pwr()
{
     p1[0]=p2[0]=1;

     for(ll i=1;i<=1000005;i++)
     {
          p1[i]=(p1[i-1]*base[0])%mod[0];
          p2[i]=(p2[i-1]*base[1])%mod[1];
     }
}

void hashing(string a,string b)
{

     ///for string a

     hash1[0][0]=hash1[1][0]=0;

     for(ll i=1;i<=a.size();i++)
     {
          hash1[0][i]=(hash1[0][i-1]*base[0] + a[i-1])%mod[0];
          hash1[1][i]=(hash1[1][i-1]*base[1] + a[i-1])%mod[1];
     }

     ///for string b

     hash2[0][0]=hash2[1][0]=0;

     for(ll i=1;i<=b.size();i++)
     {
          hash2[0][i]=(hash2[0][i-1]*base[0] + b[i-1])%mod[0];
          hash2[1][i]=(hash2[1][i-1]*base[1] + b[i-1])%mod[1];
     }

}

pair<ll,ll> rangehash1(ll l,ll r)
{
     if(l==1) return {hash1[0][r],hash1[1][r]};

     ll x=(hash1[0][r] - hash1[0][l-1]*p1[r-l+1])%mod[0];

     ll y=(hash1[1][r] - hash1[1][l-1]*p2[r-l+1])%mod[1];

     if(x<0) x+=mod[0];

     if(y<0) y+=mod[1];

     return {x,y};
}

pair<ll,ll> rangehash2(ll l,ll r)
{
     if(l==1) return {hash2[0][r],hash2[1][r]};

     ll x=(hash2[0][r] - hash2[0][l-1]*p1[r-l+1])%mod[0];

     ll y=(hash2[1][r] - hash2[1][l-1]*p2[r-l+1])%mod[1];

     if(x<0) x+=mod[0];

     if(y<0) y+=mod[1];

     return {x,y};
}


int main()
{
   ios_base::sync_with_stdio(0);
   cin.tie(0);cout.tie(0);


   pwr();

   string a,b;

   ll n,m,i,j,k,l;

   test
   {
        cin>>a;

        b=a;

        reverse(b.begin(),b.end());

        hashing(a,b);

        l=k=a.size();

        m=l;

        for(i=1,j=1; k>=1; k--,j++)
        {
             pair<ll,ll>xx,yy;

             xx = rangehash1(k,l);
             yy = rangehash2(i,j);

             if(xx.first==yy.first && xx.second==yy.second)
             {
                  m=k;
             }
        }

        cout<<"Case "<<cs<<": "<<l+(m-1)<<nl;
   }

   get_lost_idiot;
}