CMSC 106 Project #7 - Sim Car Dealer Spring 2003


Due date: Sunday, May 11, before 11:00 p.m.

1 Purpose

In this project you will write a program using structures and structures which contain other structures as members, arrays of structures, and functions with structure parameters, using both call-by-value and call-by-reference.

Your Car Configurator has been a great success with Monolithic Motors, so they have asked you to write a program to manage their car sales. Your program will keep track of the car sales at several dealers, managing the inventory of cars and the quotas for the salespeople.

The program begins by reading in a list of car dealers. Next it will read in a series of commands to stock the dealers with cars, hire salespeople and assign them quotas, and sell cars. Finally, it will print out the dealer inventories and the salespeople's sales figures.

2 Project description

2.1 Program input

The input file will be divided into two sections: the list of car dealers, and the list of commands. A description of each of these sections of the input file appears below.

2.1.1 Car dealers

The first portion of the input file contains a list of car dealers. Each dealer will be listed on a separate line. Each line will contain the name of the dealer. The end of the dealer list will be indicated by the string "####". Below is a list which could appear as the first section of an input file. The actual primary_input file will be posted in the class posting account.

Friendly_Fred    
Generous_George 
Courteous_Carl  
Honest_Hal      
Decent_Dan      
Frugal_Frieda   
Haggling_Harry  
Bargain_Bill 
Easy_Eddie   
####


Assumptions:

2.1.2 Commands

The second section of the input file will contain a list of commands to manage the car dealerships. Each command will be on a separate line. The commands will start with the name of the command and be followed by various parameters, depending on the type of command. The program will continue reading and processing commands until the end of the input.

Below is a list of commands which could appear in the second section of an input file. The actual primary_input file will be posted in the class posting account.

THIS IS FOR FORMAT REFERENCE ONLY.  ACTUAL PRIMARY DATA WILL BE POSTED.

stock Friendly_Fred      Road_Hog LX         blanched_almond 18000 20700
stock Courteous_Carl     Gas_Guzzler DX      lemon_chiffon  15000 17800
hire Friendly_Fred 1249379516 5000
stock  Generous_George   Crash_Wagon EX    light_salmon      16000 18000
stock  Honest_Hal        Heap_Mobile DX         papaya_whip   17000 19000
stock Friendly_Fred      Road_Hog DX         blanched_almond 17000 19700
hire Friendly_Fred 3474317595 6000
stock Courteous_Carl     Gas_Guzzler EX      lemon_chiffon  15000 17800
stock  Generous_George   Crash_Wagon LX    light_salmon      16000 18000
stock  Honest_Hal        Heap_Mobile EX         papaya_whip   19000 22000
hire Friendly_Foo 4565358402 3000
stock Friendly_Fred      Gas_Guzzler DX         blanched_almond 18000 20700
stock Courteous_Carl     Road_Hog EX      lemon_chiffon  25000 27800
sell Friendly_Fred Gas_Guzzler DX      lemon_chiffon 16000 
sell Friendly_Foo  Gas_Guzzler DX      lemon_chiffon 16000 
sell Friendly_Fred Crash_Wagon DX      lemon_chiffon 16000 
sell Honest_Hal    Heap_Mobile DX      lemon_chiffon 16000 
sell Friendly_Fred      Road_Hog DX         blanched_almond 19000 
sell Friendly_Fred      Road_Hog DX         blanched_almond 21700 
stock Friendly_Fred      Road_Hog DX         blanched_almond 18500 20700.95
sell Friendly_Fred      Road_Hog DX         blanched_almond 21700


Assumptions:

Please notice that there is no limit to the number of commands that may be listed in this section, so you must process them one at a time rather than trying to read them all into an array and then process them. This section does not terminate with any special symbols.

2.2 Data structures

You must follow the instructions in this section very carefully or you will lose a lot of credit for this project. You will define the following four structure types for use with this project. (You may also define others if you find them useful.)

  1. Salesperson structures have 3 members:
  2. Car structures have 4 members:
  3. Model structures have 3 members:
  4. Dealer structures have 5 members:

Important: Individual cars must be stored using a Car structure. A dealer's inventory must be stored using an array of Model structures.

2.3 Processing and output

  1. Begin by reading in the list of dealers. Store the data about each dealer in the members of a Dealer structure. Be sure to initialize the other members of the Dealer structure as well.
  2. Continue processing by reading each command and performing the operation it describes. Be sure to completely process one command before going on to the next command. You may assume that each command will be on a separate line, and there will be the proper number and format of parameters on a command line. The commands are processed as follows:

If any command contains a dealer name which doesn't exist, the program prints a message of the form:

Dealer d not found.
where d is the name of the dealer, and goes on to the next command.

The program continues reading and processing commands until the end of the input. After all of the commands have been processed, the program prints a report containing the inventory and quota information for each dealer. The dealers are listed in the order in which they were originally read in. For each dealer, the cars in the inventory are listed by model, with the models listed in the order in which they were originally stored. The cars are listed in the order in which they were originally put in stock. The salespeople are listed in the order in which they have achieved their quota, with the best performer listed first. Quota achievement is defined as the difference between the sales credit amount and the quota amount. Each salesperson ID is listed with the amount by which the sales credit is greater or less than the quota (negative value). If 2 salespeople have the same quota achievement, then the one with the smaller ID value is listed first. All of the items in the report must be aligned neatly in columns, as shown in the primary output file.

2.4 Primary Output

The primary_output file will be posted in the class posting account. As usual, it is important for you to check your output against ours using the diff command.

3 Project requirements

Your program must contain (and use) at least eight separate structure functions. A structure function either has a structure as a parameter, a structure as its return value, or has a pointer to a structure as a parameter. To get more practice using functions with structures, and to make your program easier to develop and test, it is highly recommended that you write more than eight structure functions (that you write as many as possible). At least two of your structure functions must use call-by-value for their structure parameter(s) or must have a structure as their return value. At least two of the functions must use call-by-reference for their structures, so they must have pointers to structures as parameters, and they must access the structures through the pointers.

If your program doesn't contain, and call, at least eight structure functions, of the types indicated, it will be graded as if it does not work on the primary input- even if its output is correct.

All your C programs in this course should be written in ANSI C, which means they must compile and run correctly with cc -std1 -trapuv on the OIT UNIX Class Cluster. You will lose credit if your program generates any warning messages when it is compiled. Prototypes must appear for all functions used, listed at the top of the program file.

You may use any ANSI C language features we have discussed in the course so far, plus anything we will discuss between now and the end of the semester, with the following exceptions:


Using any of these disallowed C features will result in losing credit.

Your program must have a comment near the top which contains your name, login ID, student ID, your section number, your TA's name, and an original description of the action and operation of the program. In addition, you must have a comment before each function, explaining its action and operation. Your program should be written using good programming style and formatting, as discussed in class and throughout your textbook. For this project, style is considered to consist of:


4 Developing your program

You may want to skip this section at first, read the rest of the project, and come back to study it carefully when you are about to begin writing your program.

The more you write functions to perform various manipulations on structures, the easier your code becomes to test. It is really recommended you use functions for each separate, discrete operation to be performed on any structure.

Here are some suggestions for possible functions. You do not have to use these, and you may use as many other functions as you want:


Do not use a global structure variable or array, like your book does in its example in Chapter 16! You will lose substantial credit if you use global variables in your project.

4.1 Finding compilation errors

If you get an error from the first line of your first function involving a particular structure type, which identifies a syntax error right after the name of the structure type, you probably have declared the structure type after this function which uses it. All structure type definitions must precede the first use of a variable or parameter of that structure type.

Here are several other common compilation errors having to do with structures produced by the cc compiler on our class machines and what they mean:


4.2 Program debugging


  1. Add lots of debug printf statements if your code isn't working, to find out where! You need to know this before you can find out why the problem is occurring.

  2. Draw lots of pictures of your structure types to trace exactly where things are in memory.

  3. If after you have tried these techniques, and tested each of your functions, you still can't figure out why your program doesn't work, bring a printout to our office hours, and we can help you learn how to track the problem down.

4.3 Helpful hints

Frequently save backup copies of your program under different names or in different subdirectories, so even if you inadvertently delete your file or change things which you realize you shouldn't have, it's easy to recover a recent version.

5 Academic integrity statement

Any evidence of unauthorized use of computer accounts or cooperation on projects will be submitted to the Student Honor Council, which could result in an XF for the course, suspension, or expulsion from the University. Projects are to be written INDIVIDUALLY. For academic honesty purposes, projects are to be considered comparable to a take-home exam. Any cooperation or exchange of ideas which would be prohibited on an exam is also prohibited on a project assignment, and WILL BE REPORTED to the Honor Council.


VIOLATIONS OF ACADEMIC HONESTY INCLUDE:


  1. failing to do all or any of the work on a project by yourself, other than assistance from the instructional staff.

  2. using any ideas or any part of another student's project, or copying any other individual's work in any way.

  3. giving any parts or ideas from your project, including test data, to another student.

  4. having programs on an open account or on a PC that other students can access.

  5. transferring any part of a project to or from another student or individual by any means, electronic or otherwise.


IT IS THE RESPONSIBILITY, UNDER THE UNIVERSITY HONOR POLICY, OF ANY STUDENT WHO LEARNS OF AN INCIDENT OF ACADEMIC DISHONESTY TO REPORT IT TO THEIR INSTRUCTOR.

6 Submitting your project

Your project must be electronically submitted by the date above, to avoid losing credit as described on the syllabus. No projects more than two days late will be accepted for credit without prior permission or a valid medical excuse, as described on your syllabus. Only the project which you electronically submit, according to the procedures provided, can be graded; it is your responsibility to test your program and verify that it works properly before submitting. Lost passwords or other system problems do not constitute valid justifications for late projects, so do not put off working on your program or wait to submit it at the last minute!

Turn in your assignment using the ``submit'' program as before, except using ``7'' for the project number. You are to submit only the .c file containing your source code, not the executable version of your program! If your program is in a file named ``p7.c'', submit would be run as submit 7 p7.c.

Before you submit your project, you must exactly follow the specific submission checklist in the ``Testing projects before submitting'' handout separately posted by your instructor!



Steve Scolnik 2003-05-02