CS 202 Fall 2013
Assignment 4

Assignment 4 is due at 2 p.m. Wednesday, October 9. It is worth 30 points.

Procedures

Complete each of the exercises below. Then turn in your work as follows.

1. Run Check. Demonstrate the code you have written for the exercises below to either the instructor (Glenn G. Chappell) or the T.A. (Zak Williams). Get official approval.
2. Submission. Submit your code using Blackboard, under Assignment 4 for this class. You should only submit code that has already passed the Run Check. Be sure you attach your source/header files; do not paste them into the text box. Also, send only source & headers; no project files or executables.

We may not look at your homework submission immediately. If you have questions, e-mail me.

Exercises (30 pts total)

Do each of the following exercises. Coding standards are as on Assignment 3.

Exercise A—Class with Operators

Finish class DollarCent, implemented in files dollarcent.h & dollarcent.cpp. Unfinished versions of these files are on the class webpage.

Class DollarCent keeps track of an amount of money, in dollars and cents. The dollar value must be an integer. If the amount of money is nonnegative, then the cent value must be an integer in the range \([0,99]\). If the amount of money is negative, then the cent value must be an integer in the range \([-99,0]\). For example, the value $3.29 would be represented by a dollar amount of \(3\) and a cent amount of \(29\). The value $−3.29 would be represented by a dollar amount of \(-3\) and a cent amount of \(-29\).

To finish the class, write the following operators, all of which should follow standard conventions.

+=

Takes two DollarCent objects. Adds the monetary value of the second to the first.

Binary +

Takes two DollarCent objects. Returns the sum of their monetarthy values, as a DollarCent object.

-=

Takes two DollarCent objects. Subtracts the monetary value of the second from the first.

Binary -

Takes two DollarCent objects. Returns the difference of their monetary values, as a DollarCent object.

Unary -

Takes one DollarCent object. Returns its monetary value with the sign flipped, as a DollarCent object.

Comparison operators ==, !=, <, <=, >, >=

Compare monetary values.

<<

Stream insertion, handled as usual. Examples of printed forms:

$1.20    $-8.39    $0.00    $1234.56    $0.16

Note that there are always exactly two digits after the decimal point and at least one digit before it. Other than the zeroes necessary to follow those rules, there are no leading or trailing zeroes. There are never leading or trailing blanks.

Test Program

A test program is available: dollarcent_test.cpp. If you compile and run this program (unmodified!) with your code, then it will test whether your code works properly.

Notes & Misc Requirements

• You may change the internal implementation of class DollarCent any way you like. But the result must compile with the test program and pass all tests.
• You are not being asked to write a program. Do not write “main”!
• Remember “DRY”. Good code only includes one description of how to perform any particular operation.
• Your code should not produce any output other than that required above.
• As we have done in class, I strongly suggest that you first get the class to compile with the test program. Only then should you make it work properly.

Exercise B—Collection of Similar Classes

Write classes StarPrint, LinePrint, and BackPrint and a driver program that uses them.

• Each class should be implemented in a header/source pair named as usual (“starprint.h” & “starprint.cpp”, etc.)
• An object of each class should act as if it maintains a message, stored in a string, and a count: a positive integer.
• Each class should have the following member functions:
  • Constructor from string, int. Sets the message and the count to the given values.
  • Constructor from string. Set the message to the given value and the count to 1.
  • Default constructor. Sets the message to an empty string and the count to 1.
  • Get and set functions, as usual: getMessage, setMessage, getCount, setCount.
  • Function print, which takes an optional ostream (defaults to cout) and prints the message to the stream as specified below.
• When printing:
  • A StarPrint object should print count stars, a blank, the message, and then count stars again, followed by a newline. With a message of "abcde" and a count of 3, it would print

    *** abcde ***

  • A LinePrint object should print count lines of dashes, each the same length as the message, then the message on a separate line, then count lines of dashes again, ending with a newline. With a message of "abcde" and a count of 3, it would print

    -----
    -----
    -----
    abcde
    -----
    -----
    -----

  • A BackPrint object should print count copies of the message backwards, each on a separate line. ending with a newline. With a message of "abcde" and a count of 3, it would print

    edcba
    edcba
    edcba

• Your driver program should create three vectors, one of StarPrint objects, one of LinePrint objects, and one of BackPrint objects. Each vector should contain at least two objects. The program should then go through each vector and call the print member function of each of the objects.