I was learning string hashing on spoj and they have suggested to solve this problem using naive approach and i tried but i am getting wrong ans and i am not able to figure out where i am making mistake ? Question link : https://www.spoj.com/problems/SUB_PROB/

My solution :

#include<bits/stdc++.h>
using namespace std;
const int p = 67;
const long long m = 1e9+9;
	
long long  count_hash(string s)
{
	long long  hash_value = 0,pow_p = 1;

	for(int i =0;i<s.size();i++)
	{
		if (s[i] >= 'a' && s[i] <= 'z')
			hash_value = (hash_value + (s[i] - 'a' +1 )*pow_p)%m;
		else if (s[i] >= 'A' && s[i] <= 'Z')
			hash_value = (hash_value + (s[i] - 'A' +1 )*pow_p)%m;
		else
			hash_value = (hash_value + (s[i] - '1' +1 )*pow_p)%m;
			
		pow_p = (pow_p*p)%m;
	}

	return hash_value;
}
void check_substring(string main_string,int n)
{
	int X= main_string.size();
	
	vector<long long> pow_p(X);
	pow_p[0] = 1;
	for(int i =1;i<X;i++)
		pow_p[i] = (pow_p[i-1]*p)%m;
	
	vector<long long> hash_main_string(X+1,0);

	for(int i =0;i<X;i++)
	{
		if (main_string[i] >= 'a' && main_string[i] <= 'z')
			hash_main_string[i+1] = (hash_main_string[i] + (main_string[i] - 'a' + 1) * pow_p[i])%m;
		else if (main_string[i] >= 'A' && main_string[i] <= 'Z')
			hash_main_string[i+1] = (hash_main_string[i] + (main_string[i] - 'A' + 1) * pow_p[i])%m;
		else
			hash_main_string[i+1] = (hash_main_string[i] + (main_string[i] - '1' + 1) * pow_p[i])%m;
		
	}
		
	/*for(int i =0;i<=X;i++)
	{
		cout<<hash_main_string[i]<<"\n";
	}*/
	while(n--)
	{
		string s;
		cin>>s;

		int hs = count_hash(s);
		//cout<<"hs = "<<hs<<"\n";
		int flag = 0;
		for(int l = 1;l<=X-s.size()+1;l++)
		{
			long long cur_h = ((hash_main_string[l-1+s.size()]+m-hash_main_string[l-1])%m);
		//	cout<<cur_h<<"\n";
		//	cout<<"updated hs = "<<(hs*pow_p[l-1])%m<<"\n";
			if (cur_h == ((hs*pow_p[l-1])%m))
			{
				flag = 1;
				break;
			} 
		
		}

		if (flag == 1)
			cout<<"Y\n";
		else
		{
			cout<<"N\n";
		}
		
	}
}
int main()
{
	string s;
	while(cin>>s)
	{
		int n;
		cin>>n;
		check_substring(s,n); 
	}
	return 0;
}