CSE 142 Autumn 2000 Homework #1

Galleons, Sickles, and Knuts

• assigned October 2, 2000
• due:
  • web submission by 10:00 pm, Sunday, October 8, 2000
  • paper submission in lecture Monday, October 9, 2000, or in the homework drop box on the first floor of Sieg by 3:00 pm, Monday, October 9.

• introduction
• key concepts
• specifications
• programming requirements
• submission guidelines (includes link to turn-in page)
• files
• a few bits of advice
• announcements

As the new programming wizard at Hogwarts School of Wizardry, you are being given a series of tasks to make the magical world run more smoothly. Your first task is to assist Gringott's Bank in the conversion of currency from Magical Money (Galleons, Sickles, and Knuts) to Muggle Money (Euros). You have been asked to create a program which prompts the user for an amount of money in Galleons, Sickles, and Knuts, converts it to Euros, and also computes the commission that Gringotts charges. Information on conversion rates and commissions are given below.

Key Concepts

In this section, for most homeworks, we'll provide a list some of the relevant concepts. Don't forget, however, that CS is a lot like math in that you can never afford to forget concepts you learned earlier in the course; every new homework and programming concept builds on previously learned ones. In addition, later in the quarter, determining which concepts you should apply might well be part of your homework.

In this homework, keep an eye out for...

• the programming process: studying the problem, planning a solution, writing code
• input/output (I/O with printf and scanf)
• variables and assignments
• constants (using #define)
• expressions with arithmetic operators (e.g. + - * / %)

Your program should prompt the user to enter (in order) the number Galleons, Sickles, and Knuts to exchange into Euros. The program should then convert to Euros and calculate the commission to charge. The program should print the value in Euros, the commission in Euros, and the amount to be paid to the customer.

There are 17 Sickles in a Galleon, and 29 Knuts in a Sickle. You may use the conversion rate that one Galleon is worth 60.0 Euros. The commission charged by Gringott's is 5.0 %.

You should read in the Galleons, Sickles, and Knuts as ints. Use doubles to represent the amount in Euros and the commission. The sample executable uses the formatting code %.2lf to display a double to two decimal digits.

Your program should run like the sample executable we have provided on the web. The computed numbers should be very close. (Note - the computation can be done in several different ways - because of rounding, the answers may differ in the last displayed digit.) The spacing in the output doesn't have to be identical, but the order of the inputs and outputs must match exactly. (When we can, we use automated scripts to test submitted programs, which is one reason that it is important that your program accepts input and produces output in the same order as the sample program.  The other reason consistency is important is TA sanity when they grade dozens of programs.)

Your program should prompt the user for inputs and give descriptive messages of the output, but does not need to match all of the verbiage of the sample solution.

It is important that your program be well-written, as well as work correctly.  Besides general guidelines like picking good variable names, there a few specific things that are required for this assignment. 

• Use #define to give meaningful names to significant constants.  In particular, the relationships between Galleons, Sickles, and Knuts, the conversion factor, and the commission rate should be given names using #define, not written directly into expressions in your program.
• You may not use conditional statements or loops (if, while, for, etc.) in this assignment.  The program can be written using only input and output plus assignment statements.
• Be sure to use int and double (floating-point) variables appropriately in your program.

The due date for this assignment is at the top of this page. Be especially aware of the web submission deadline, as submission times are tracked precisely and we cannot accept late submissions.

• web turn-in page

• self-extracting archive, including starter C file
  • hw1_vc6.exe - for use with MSVC 6.0
  • hw1_vc5.exe - for use with MSVC 5.0
• hw1_orig.c - starter C file alone (useful for other C programming environments)
• hw1.exe - sample executable

• Start early. Despite the fact that it improves your life immensely, so many people ignore this advice. It always pays to get an early start.
• Read these instructions completely and carefully.
• Try running the sample executable with various input values.
• Before writing a single line of code, plan your solution on paper. Try thinking about what you would do to perform the computations yourself.
• Develop and test the program a bit at a time.  Don't try to write the whole program and test it all at once.  Instead, try getting a small part working (say reading in and converting Galleons to Euros).  Once you've gotten that far, it will be easier to add more pieces until the whole job is done.
• Before turning in your work, test it thoroughly, comparing results with the sample executable.
• When it comes to grading, there's nothing better than a happy TA. Make your TA a happy TA: Your code should be neat and readable, with sensible variable names.
• Start right now!

Background

If any clarifications or changes need to be made for this homework, they will be posted to the cse142-announce email list and linked here.