CEng 242 Homework 4
Due: 28 ^th April 2000

Define a C++ class Wallet with the following features:
It can contain cash with 5 types of bills: 1,5,25,50 and 100. There can be at most 20 bills in a Wallet. Also a Wallet can contain at most 5 credit cards. Each credit card has a name with at most 40 characters (longer names should simply be cropped) and a positive limit which is not greater than 1000. Credit card storage should be allocated when the first card is added and deallocated when the last card is deleted. Also you should write the destructor deallocating it.

Your should implement the following methods or functions:

• Wallet()
  Constructor without any argument should create an instance with 0 cash and no credit card.
• Wallet(int,int,int,int,int)
  Constructor with number of bills corresponding to 1,5,25,50,100 respectively. All parameters should have a default of 0. All parameters should have a default of 0. It will construct an empty Wallet if total count of bills exceeds 20.
• int addBill(int,int)
  w.addBill(bill,count) will add count bills of value bill to Wallet object w.
• int addCard(const char *,int)
  w.addCard(name,credit) will add the credit card named name with credit credit to Wallet object w. If a credit card with same name exists, it is updated by adding the credit to existing credit of the card.
• int deleteBill(int,int)
  w.deleteBill(bill,count) will drop count bills of value bill to Wallet object w.
• int deleteCard(const char *)
  w.deleteCard(name) will delete the given credit card from Wallet object w.
• int cash()
  w.cash() will return the amount of the cash money in the wallet.
• int credit()
  w.credit() will return the total credit in the wallet.
• int total()
  w.total() will return the amount of all spendable money in the wallet including cash and total credit.
• int operator-=(int)
  w-=amount will pay the amount from the wallet using the following order:
  • If there are some bills in the wallet, try to pay partially or whole payment from bills.
  • If you cannot pay with the exact amount, but there are some bills left, try to give the maximum amount less than the exact amount
  • If there is no enough bill in the wallet. Pay all bills, than pay the rest from credit cards.
  • Allways pay from the credit card with largest credit. If credit is not enough, combine several credit cards. Delete the credit card with 0 credit.

  Note that bill configuration is changed. New configuration can be solved in a very easy algorithm: start from the greatest bill, pay the maximum smaller than amount, than pay the rest from smaller bills using the same algorithm.

• ostream & operator<<(ostream &,Wallet &)
  stream << w will display the wallet w on stream and return the stream. Credit cards should be sorted according to card names in the output.

      1*4+5*2+25*0+50*1+100*3=364
      "HiperBank": 175
      "HirsizBank": 950
      "UltraBank": 200
      Credit: 1325 Total: 1689

All functions are methods of Wallet except the last one that is an overloading of the operator <<. You should also overload assignment operator = to have the result of assignment work properly (instead of pointer assignment).

For errors you are given the following definitions:

#define NOERR            0
#define CREDITOVERFLOW   1
#define CARDOVERFLOW     2
#define INVALIDBILL      3
#define BILLOVERFLOW     4
#define CARDNOTFOUND     5
#define NOTENOUGHBILL    6

For all of the operations except cash(),credit() and total() you should return the following values:

• NOERR
  Operation completed successfully.
• CREDITOVERFLOW
  Result of addCard exceeds the credit per card limit 1000 or a negative credit parameter is given.
• CARDOVERFLOW
  Result of addCard exceeds the number of cards 5.
• INVALIDBILL
  Bill parameter of addBill or deleteBill is not a valid bill value.
• BILLOVERFLOW
  Result of addBill exceeds the total bill number 20 or a negative bill count parameter is given.
• CARDNOTFOUND
  Card name in deleteCard is not found.
• NOTENOUGHBILL
  There is not enough number of bills in wallet for deleteBill request.
• -amount
  There is not enough amount in the bills or credit cards to make the payment in -= request. Return value should be the remaining amount which could not be paid as a negative number.

For cases with both INVALIDBILL and BILLOVERFLOW, return INVALIDBILL. For cases with both CARDOVERFLOW and CREDITOVERFLOW generate CARDOVERFLOW. When constructor(s) are used with invalid parameters causing BILLOVERFLOW or any other errors, then silenty create an empty Wallet without any bill.

When an operation with an error is requested, object will not be modified and one of the listed return values will be returned. There should be no invalid Wallet object generated by your methods.

You should implement your homework in 3 files:
wallet.h, wallet.cpp and hw4.cpp. wallet.h will contain your class definition only. wallet.cpp will include this header file and contain the implementation of your methods and functions. hw4.cpp will include the header file and contain your main() function. You will submit a tared,gziped file of wallet.h and wallet.cpp only. For example:
tar cf - wallet.h wallet.cpp | gzip -c >hw4.tar.gz
submit242 hw4.tar.gz

Do not include the file with main program into your submission!

During your development, you can use the following makefile. Indentation in the second line comes from a tab character. Write these lines into a file called makefile and for compilation just write make:

hw4: wallet.h wallet.cpp hw4.cpp
       g++ -o hw4 wallet.cpp hw4.cpp

Details of the submission procedure and output format may be changed. Changes will be announced in the newsgroup.