// File: account.h
// Header file for the account class
class account
{
protected:
   double balance;     // current balance
public:
   account(double bal); // the constructor
   account(void);       // default constructor
   void deposit(double amt);
   double getBalance(void);
}; // account


// File: account.cpp
// implementation file for the account class
#include "account.h"
account::account(double bal)
{
   balance = bal;
}

account::account(void)
{
   balance = 0;
}

void account::deposit(double amt)
{
   balance += amt;
}

double account::getBalance(void)
{
   return balance;
}

// file accountDemo.cpp
#include <iostream.h>
#include "account.h"

void main(void)
{
   account a(50.45), b;   // a has $50.45, b has $0.0 initially

   a.deposit(30);
   cout << " account a now has $" << a.getBalance() << endl;
   b.deposit(130);
   cout << " account a now has $" << b.getBalance() << endl;
}



// File: checkingAccount.h
// header file for the checkingAccount class
#include "account.h"
class checkingAccount : public account  // inherits from account class
{
protected:
   double limit;      // lower limit for free checking
   double charge;     // per-check charge for low balance
public:
   checkingAccount(double bal, double lim, double chg);
   double cashCheck(double amt);
};



// File: checkingAccount.cpp
// implementation file for class checkingAccount
#include "checkingAccount.h"
checkingAccount::checkingAccount( double bal, 
                                  double lim, 
                                  double chg) : account( bal )
{
   limit = lim;
   charge = chg;
}

double checkingAccount::cashCheck(double amt)
{
   if ((balance < limit) && (amt + charge <= balance))
   { 
      balance -= amt + charge;
      return amt + charge;
   }
   else if ((balance >= limit) && (amt <= balance))
   {
      balance -= amt;
      return amt;
   }
   else
      return 0.0;
}