Project 8, Program Design Solved

    1. (100 points) The daily sales of a grocery store are saved in the file sale.txt. Each line contains the record for a product name, price per pound in dollars, and total number of pounds sold. Write a program that reads file sale.txt, store the data in an array of product structures, and sort the products by sale volume. Output the sorted products, including sale volumes in a text file called sorted_products.txt. A product structure should have the following attributes:

o
name
string
o
unit price
double
o  total number of pounds sold
double
o
sale volume
double



You can assume the sale.txt as the following format for each product: product name (one single word), unit price, total numbers of pounds sold.

apple, 2.5, 421.4



    1. Name your program product.c.

    2. The program should be built around an array of structures, with each structure containing information of a product’s name, unit price, total numbers of pounds sold, sale volume (unit price * total numbers of pounds sold). Assume that there are no more than 1000 products in the file.

    3. Use fscanf and fprintf to read and write data.

    4. Modify the selection_sort function for sorting integers to sort an array of product struct. The boxes should be sorted by sale volume in ascending order. The function should have the following prototype:


void selection_sort(struct product products[], int n);


    5. Output the sorted products, including sale volumes, in a text file called sorted_products.txt, in the following format.



#name unit price ($) units (pound) sold

sale volume ($)
celery
2.300000
99.450000
228.735000
blueberry
3.500000
87.300000
305.550000
potato
0.600000
823.650000
494.190000

…
    2. Extra credit (20 points) Modify the program (Name your program product2.c) so it takes command line argument for the product name and the program displays unit price, total numbers of pounds sold, and sale volume of the product. The program should include the following function:

void find_product(struct product products[], int n, char *name);



The find_product function should find the product by name, print the product’s unit price, total numbers of pounds sold, and sale volume with two decimal digits.

Example run:

./a.out grape

Output:

Name: grape

Unit price: 2.25

Number of pounds sold: 393.50

Sale volume: 885.38



Before you submit:



1. Compile with –Wall. Be sure it compiles on circe with no errors and no warnings.



gcc –Wall product.c



2. Be sure your Unix source file is read & write protected. Change Unix file permission on Unix:



chmod 600 product.c



    3. Submit both product.c and sale.txt (for grading purposes).



    4. If you choose to do the extra credit problem, please submit a separate program:

product2.c

Total points: 100 + 20(extra credit)



    1. A program that does not compile will result in a zero.
    2. Runtime error and compilation warning 5%
    3. Commenting and style 15%
    4. Functionality 80% (functions were declared and implemented as required)




Programming Style Guidelines

The major purpose of programming style guidelines is to make programs easy to read and understand. Good programming style helps make it possible for a person knowledgeable in the application area to quickly read a program and understand how it works.

    1. Your program should begin with a comment that briefly summarizes what it does. This comment should also include your name.

    2. In most cases, a function should have a brief comment above its definition describing what it does. Other than that, comments should be written only needed in order for a reader to understand what is happening.

    3. Information to include in the comment for a function: name of the function, purpose of the function, meaning of each parameter, description of return value (if any), description of side effects (if any, such as modifying external variables)

    4. Variable names and function names should be sufficiently descriptive that a knowledgeable reader can easily understand what the variable means and what the function does. If this is not possible, comments should be added to make the meaning clear.

    5. Use consistent indentation to emphasize block structure.

    6. Full line comments inside function bodies should conform to the indentation of the code where they appear.

    7. Macro definitions (#define) should be used for defining symbolic names for numeric constants. For example: #define PI 3.141592

    8. Use names of moderate length for variables. Most names should be between 2 and 12 letters long.

    9. Use underscores to make compound names easier to read: tot_vol or total_volumn is clearer than totalvolumn.