CS 1005, C-term 03
Homework 1
Calculating change

Due: January 21, 2003 at 11:59pm

Assignment

Write a C++ program that takes as input the total amount of a customer's purchases and the cash tendered by the customer, and outputs the change to be returned so that the number of coins is a minimum.

Outcomes

After successfully completing this assignment, you will...

Before Starting

Read Chapter 0 and Chapter 1

Details about the Program

The solution to this problem requires an understanding of converting numbers from one data type to another. Remember that variables of type float are approximations, and that when C++ converts from float to int, it truncates the decimal portion of the number. (You may find it necessary to round numbers before converting from one type to another - a quick and easy way to round off a positive number to the nearest whole number is to add 0.5, then truncate.)

Since this program deals with dollars and cents, you should output all floating point numbers with two digits to the right of the decimal point. See Floating Point Output Formats on the class webpage for a discussion of this topic.

The only statements needed for this program are declarations, input and output statements, and assignment statements.

Sample Execution 

  This program will calculate your change, given the cost of your
  purchases and the amount of money tendered.  The minimum number
  of coins will be returned in your change.

  Enter the total amount of your purchases:  $3.39
  Enter the amount of cash tendered:  $10.00

  The cash to be returned is $6.61
  The number of quarters returned is 2
  The number of dimes returned is 1
  The number of nickels returned is 0
  The number of pennies returned is 1

  Program terminating...

Include files

iostream allows you to use cin, cout, endl

iomanip allows you to use setprecision

Assumptions and restrictions

You may assume that the user of the program enters numeric values for the amount of the purchases and the amount of money tendered. You may also assume that the amount tendered is greater than or equal to the amount of the purchases.

Program style and Comments

There's a lot more to programming than writing code that works. A good program is well-documented. Each program must contain in the comments your name and section number, and the date. The purpose of the program should be stated. Declared variables need to be explained with brief comments; use meaningful identifiers. Comments should be used to clarify obscure sections of code, but be careful - over-commenting can be worse than not including comments at all. Blank lines should separate major sections of the program. Indentation should make the program easy to read, and it should be used consistently. Refer to Documentation Guidelines for specific guidelines on how to document your programs for this course.

Deliverables

All homework assignments must be turned in electronically, using the turnin program, which is accessible from any CCC connection. To submit your program for grading, follow the steps outlined below:
  1. Create a typescript file: A typescript file is a file which contains a transcript of a session at the computer. The program which allows you to create typescript files is called script. To use script simply type 
    script hw1.script
    This will cause all the text that appears on the screen after script is started to be stored in a file called hw1.script. To stop the script program type the command 
    exit
    You are required to submit with all homeworks a typescript file that contains a transcript of the homework being compiled and run. For this assignment you should create your typescript file this way: 
    >script hw1.script
Script started, file is hw1.script
>g++ -Wall hw1.cxx
>a.out

...the execution of your program...

exit
  2. Create a documentation file: Several years ago the CS department approved a documentation format to be used for the external documentation of programs developed in introductory CS courses. All assignments for CS 1005 must be documented according to this format, and the documentation file must be submitted when you use turnin. Name your documentation file README. The documentation standard is described fully on the Web page found here For this class, you must complete the following sections of the documentation format:

    All other sections should be completed by filling in ``N/A''. A sample of a C program documented using this format can be found here . A template of the documentation format can be found here . This template can be copied to your home directory, where you can edit it in preparation for submission to turnin. Please note that turnin accepts ASCII text files only, so you should use an editor (like emacs on Unix or Notepad on a PC), not a word processor, when you create your documentation file (in particular, do NOT use Microsoft Word).

  3. Use the turnin program: All homework must be submitted using the turnin program. You may not turn in your program on disk, by email, or as a printout. The turnin program copies files to a directory from which they will be graded by the TA's. To use turnin to submit a set of files type 
    /cs/bin/turnin submit cs1005 project file1 file2 ... filen
    where project will be the name of the assignment you are turning in (either hw1, hw2,... or lab1, lab2...) and where file1 through filen are the files you wish to submit. Whenever a file is submitted via turnin, it is copied to the cs1005 turnin directory and the date and time of the turnin operation are noted in the files. Any attempts to resubmit the files will overwrite the previously submitted files. If you turn in your homework prior to the due date and realize that the program you submitted had errors, you may correct the errors and use turnin again to turn in the corrected program. The old file(s) will be overwritten by the new ones and the date and time of the second turnin will be noted. The grader will see just the last submitted copy. To use turnin for this assignment type: 
    /cs/bin/turnin submit cs1005 hw1 hw1.cxx hw1.script README
    A message stating ``done submitting files'' should appear. You may verify that all your files were successfully submitted with the command 
    /cs/bin/turnin verify cs1005 hw1
    If you are not sure that your files were correctly submitted, ask a TA for help. You will be responsible for submitting all your files on time; don't wait until the last minute to use turnin. This assignment is due at 11:59 pm on Tuesday, January 21.

Grading

This assignment will be graded on 100 points. Point values will be allocated as follows: