Account class design using OOP paradigm - c++

Question

I want to design an account management system.I have an account class for storing the details of each account, a withdrawal class for storing the information regarding the money withdrawn from a particular account and an account list class with an array of accounts and member function add_acc,search_acc that searches for a particular account and show_acc that displays information of all the accounts. But before adding an account, I want to check if the account no. to be added, already exists or not. If it exists then an error message is displayed else the new account is added.But the show_acc function is not functioning, everytime it is called, it prints some garbage value.
#include <iostream>
#include <stdlib.h>
using namespace std;
#define MAX 100
void Withdrawal(class Account_list &a);
class Account
{
long long int acc_no;
long double balance;
public :
void get_data(long long int acc,long double b=0)
{
acc=acc_no;
b=balance;
}
void show_data()
{
cout<<"Account no. : "<<acc_no<<endl;
cout<<"Balance : "<<balance<<endl;
}
long long int get_acc_no()
{
return acc_no;
}
long double get_balance()
{
return balance;
}
void update(long double b)
{
balance=balance-b;
}
friend class Account_list;
};
class Account_list
{
static int count;
Account A[MAX];
public:
void add_acc();
void show_acc();
void search_acc(long long int);
friend void Withdrawal(Account_list &a);
};
int Account_list::count=0;
void Account_list::add_acc()
{
long long int acc;
long double b;
cout<<"Enter account number : ";
cin>>acc;
cout<<"Enter balance : ";
cin>>b;
for (int i = 0; i <= count; i++)
{
if (A[i].get_acc_no() == acc)
{
cout << "\nAccount already exists enter a unique account number\n";
return;
}
}
A[count].get_data(acc, b);
count++;
}
void Account_list::search_acc(long long int ac)
{
for(int i=0;i<count;i++)
{
if(A[i].get_acc_no()==ac)
{
A[i].show_data();
return;
}
}
cout<<"Account no. not found please enter a valid account no.";
}
void Account_list::show_acc()
{
for(int i=0;i<count;i++)
{
A[i].show_data();
cout<<endl<<endl;
}
}
void Withdrawal(Account_list &a)
{
long long int acc;
long double amount;
cout<<"Enter the account no. : ";
cin>>acc;
cout<<"Enter the amount to be withdrawn : ";
cin>>amount;
for(int i=0;i<a.count;i++)
{
if(a.A[i].get_acc_no()==acc && a.A[i].get_balance()>amount)
{
a.A[i].update(amount);
cout<<"Amount withdrawn successfully\n";
return;
}
}
cout<<"Account no. not found or invalid withdrawal amount entered";
}
int main()
{
Account_list A;
char ch='Y';
long long int acc;
int i;
while(ch)
{
cout<<"1. Add account"<<"\n"<<"2. Find account"<<"\n"<<"3. Withdraw amount"<<"\n"<<"4. Display information"<<"\n";
cout<<"Enter your choice : ";
cin>>i;
switch(i)
{
case 1: A.add_acc();
break;
case 2: cout<<"Enter the account no. to be searched : ";
cin>>acc;
A.search_acc(acc);
break;
case 3: Withdrawal(A);
break;
case 4: A.show_acc();
break;
default:cout<<"Enter a valid choice";
}
cout<<"Do you wish to continue?"<<" : ";
cin>>ch;
if(ch=='Y' || ch=='y')
{
cout<<endl;
continue;
}
else
break;
}
}
The problem with my output -:
In the first run I entered the account no. as 123, int the second run I enter the acc. no. as 345 and when in the third run again I entered the acc. no. as 345, the error message was not displayed.