IPC144 Workshop 6 Solution

Introduction
In this workshop, you will code and execute a C language program that evaluates the cheapest cat food product based on a simple analysis. Data will be entered for three similar products and then displayed back to the user in a tabular table format. The data will be analyzed and displayed with additional calculated information in the form of a formatted table revealing the analysis. The program concludes with the suggested cheapest product.
Topic(s)
• Modularity: Functions and Pointers
Learning Outcomes
Upon successful completion of this workshop, you will have demonstrated the abilities:
• to create a modularized program using functions and multiple files
• to code functions to perform a specific task
• to call a function with several arguments of different types
• to pass an address to a function in a function call
• to refer to an address stored in a function’s parameter


Submission Policy
All files you create or modify MUST contain the following 4 pieces of information; your:
1. Full name
2. Student Number
4. Section Information Code
Notes
• You are responsible for backing up your work regularly
If any Part-1, Part-2, or Reflection portions are missing, the mark will be ZERO.

Part-1 (10%)
Instructions

1. Carefully review the “Part-1 Output Example” (next section) to see how this program is expected to work
2. Do NOT MODIFY the “main1.c” file.
• This launches some pre-testing routines for two functions you need to develop:
getIntPositive and getDoublePositive (described later)
• Following the pre-testing, it will call a function “start” that is the entry-point to the logic of your program
3. The code you write will be placed in two additional files: “w6p1.h” (header file) and “w6p1.c” (source file)

File w6p1.h (header file)
4. This file will contain applicable macro’s (#define), structures, and function prototypes
5. Create a macro that represents the maximum number of products to analyze (used in sizing the array later-on) – define this to be 3
6. Create a macro that represents the number of grams (64) in a suggested serving 7. Create a structure “CatFoodInfo” with the following related members that can hold:
• a whole number for storing a product sku number (unique identifier)
• a double floating-point number for the product price
• a whole number for storing calories per suggested serving
• a double floating-point number for the product weight in pounds (lbs)
8. You will need to create seven (7) functions. In this file, you need to code the prototypes. Here are the names (case sensitive) of those functions including a short description to help you create the necessary return types and parameter information for each:
1. getIntPositive
- Returns an integer number
- Receives an address that points to a whole number data type (provide a meaningful parameter name)
- Note: This function returns the user-entered positive integer value in two ways:
o Return value
o Via the pointer argument
2. getDoublePositive
- Returns a double floating-point number
- Receives an address that points to a double floating-point data type (provide a meaningful parameter name)
- Note: This function returns the user-entered positive double floating-point value in two ways:
o Return value
o Via the pointer argument
3. openingMessage
- Does not return a value
- Receives an argument that is an unmodifiable integer value representing the number of products the user will need to enter for analyzing (provide a meaningful parameter name)
4. getCatFoodInfo
- Returns a “CatFoodInfo” type
- Receives an unmodifiable integer number representing the sequence number of the product to be entered by the user (provide a meaningful parameter name)
5. displayCatFoodHeader (this function is provided for you)
- Does not return a value nor receives any arguments
6. displayCatFoodData
- Does not return a value
- Receives multiple unmodifiable arguments representing each member of the “CatFoodInfo” type (not the structure itself)
- Match the data types according to the member types in the “CatFoodInfo” type
- Note: integer types are passed by value, but double floating-point types are passed by address
7. start
- Does not return a value nor receive any arguments
- This function acts as the main entry-point to the logic of the application (similar to what you are used to coding in “main” only this function does not return a value)

File w6p1.c (source file)
9. In this file, you will code the function definitions (the implementation of each function)
10. Include the necessary system and user-defined libraries you need for the application (system libraries use angle brackets (<>), while user-defined use double quotes ("")
11. Code each function definition implementation based on the prototypes declared in the header file. Below describes each function in a little more detail:
1. getIntPositive
- This function should accept user input for an integer value
- If the value entered is a negative or zero value, an error message should be displayed (see example output for the message to display)
- Logic should be designed to continue prompting until a positive value is entered - This function must return the entered value in two ways:
o One: by assigning the entered value to the pointer argument (only if it is NOT NULL) o Two: by “return”ing the value.
o This provides flexibility to the “caller” of the function where the value can be captured in two possible ways (or both). Refer to the main.c file to see how this function is “pre-tested”
2. getDoublePositive
- This is the same as the above described getIntPositive function, only this is for a double floating-point type.
3. openingMessage
- See the example output “Cat Food Cost Analysis…”
- Be sure to produce the number values by using the appropriate macro’s defined earlier
4. getCatFoodInfo
- Display a message to indicate the sequence number (use argument variable) o See the example output “Cat Food Product #...”
- Prompt the user to enter data for each member of a “CatFoodInfo” type
- Call appropriate helper functions to get validated user input whenever possible o Try calling the helper functions in different ways to get the return value o Suggestion-1: Try getting the function output value via the argument o Suggestion-2: Try getting the function output value via the returned value (hint:
send “NULL” as the argument)
- Return the CatFoodInfo value
5. displayCatFoodHeader (this function is provided for you)
- Use the following formatting to display the table header:
printf("SKU $Price Bag-lbs Cal/Serv "); printf("------- ---------- ---------- -------- ");
6. displayCatFoodData
- Use the following formatting do display a data row based on the arguments being received:
printf("%07d %10.2lf %10.1lf %8d "...
7. start
- This is the entry-point to the logic portion of your application (called from main)
- Create an array variable of type “CatFoodInfo” and size it using the appropriate macro defined in the header file (be sure to initialize it to a safe empty state)
- Call the necessary function that will display an opening message
- Nested inside an iteration construct that will iterate the necessary number of times, call the necessary function to get user input for each product and assign the function returned value to the appropriate element of the “CatFoodInfo” array variable (declared earlier). Hint: Send as an argument to the function, the iterator variable to represent the sequence number.
- After obtaining all the product data from the user, call the necessary function that will display the table header
- Nested inside an iteration construct, iterate the necessary number of times for each product, call the necessary function that will display each “CatFoodInfo” record (send the necessary arguments – reminder, some are pass-by-value, and others are pass-by-address).

Part-1 Output Example (Note: Use this data for submission)

============================
Pre-testing Helper Functions
============================

------------------------
Function: getIntPositive
------------------------
For each of these tests, enter the following three values (space delimited): -1 0 24

TEST-1: -1 0 24
ERROR: Enter a positive value: ERROR: Enter a positive value: <PASSED>
TEST-2: -1 0 24
ERROR: Enter a positive value: ERROR: Enter a positive value: <PASSED>
TEST-3: -1 0 24
ERROR: Enter a positive value: ERROR: Enter a positive value: <PASSED>
---------------------------
Function: getDoublePositive
---------------------------
For each of these tests, enter the following three values (space delimited): -1 0 82.5

TEST-1: -1 0 82.5
ERROR: Enter a positive value: ERROR: Enter a positive value: <PASSED>
TEST-2: -1 0 82.5
ERROR: Enter a positive value: ERROR: Enter a positive value: <PASSED>
TEST-3: -1 0 82.5
ERROR: Enter a positive value: ERROR: Enter a positive value: <PASSED>
===========================
Starting Main Program Logic
===========================

Cat Food Cost Analysis Function
openingMessage
======================

Enter the details for 3 dry food bags of product data for analysis.
NOTE: A 'serving' is 64g

Cat Food Product #1
--------------------
SKU : 0
ERROR: Enter a positive value: 12221 PRICE : $0
ERROR: Enter a positive value: 26.99
WEIGHT (LBS) : 0
ERROR: Enter a positive value: 2.5
CALORIES/SERV.: 0
ERROR: Enter a positive value: 325

Cat Food Product #2
--------------------
SKU : 23332
PRICE : $41.99
WEIGHT (LBS) : 5.5
CALORIES/SERV.: 325

Cat Food Product #3
--------------------
SKU : 34443
PRICE : $71.99
WEIGHT (LBS) : 13.0
CALORIES/SERV.: 325

SKU $Price Bag-lbs Cal/Serv
------- ---------- ---------- --------
0012221 26.99 2.5 325
0023332 41.99 5.5 325
0034443 71.99 13.0 325 Function getCatFoodInfo
Functions displayCatFoodHeader displayCatFoodData
Part-1 Submission
1. Upload (file transfer) all source and header files: “main1.c”, “w6p1.h” and “w6p1.c” to your matrix account
2. Login to matrix in an SSH terminal and change directory to where you placed your workshop source code.
3. Manually compile and run your program to make sure everything works properly:
gcc -Wall main1.c w6p1.c -o w6 <ENTER>
If there are no error/warnings are generated, execute it: w6 <ENTER>
~profName.proflastname/submit 144w6/NAA_p1 <ENTER>
5. Follow the on-screen submission instructions
Part-2 (40%)
This part will expand on Part-1 by adding the analysis component and will display the results of the analysis.
Instructions
1. Carefully copy/paste your code from w6p1.h and w6p1.c and INSERT it into the respective Part-2 source files w6p2.h and w6p2.c where the comments indicate.
2. Review the “Part-2 Output Example” (next section) to see how the program is expected to work
3. Do NOT MODIFY the “main2.c” file.
• This launches some additional pre-testing routines for three more helper functions you need to develop: convertLbsKg, convertLbsG, and calculateLbs (described later)
• It finishes with a function call to “start” that is the entry-point to the logic of your program

File w6p2.h (header file)
4. Add another macro that represents the conversion factor of the number of U.S. pounds (lbs) in a KG unit value (2.20462) – this will be used in conversions from lbs to metric units later on
5. Add another structure “ReportData” with the following related members that can hold:
• a whole number for storing a product sku number (unique identifier)
• a double floating-point number for the product price
• a whole number for storing calories per suggested serving
• a double floating-point number for the product weight in pounds (lbs)
• a double floating-point number for the product weight in kilograms (kg)
• a whole number for the product weight in grams (g)
• a double floating-point number for the total servings
• a double floating-point number for the cost per serving
• a double floating-point number for the cost of calories per serving
6. You will need to create an additional ten (10) functions. In this file, add the necessary prototypes (numbering continues from Part-1). Here are the names (case sensitive) for these new functions along with a short description to help you create the necessary return types and parameter information for each:
8. convertLbsKg
- Returns a double floating-point number
- Receives an address that points to an unmodifiable double floating-point data type representing the pounds (lbs) to be converted (provide a meaningful parameter name)
- Receives an address that points to a double floating-point data type representing the conversion result (equivalent kilograms (kg)) – provide a meaningful parameter name
- Note: This function returns the pounds (lbs) to kilograms (kg) conversion in two ways:
o Return value
o Via the pointer argument

9. convertLbsG
- Returns a whole number
- Receives an address that points to an unmodifiable double floating-point data type representing the pounds (lbs) to be converted (provide a meaningful parameter name)
- Receives an address that points to a whole number data type representing the conversion result (equivalent kilograms (kg)) – provide a meaningful parameter name
- Note: This function returns the pounds (lbs) to grams (g) conversion in two ways:
o Return value
o Via the pointer argument
10. convertLbs
- Does not return a value
- Receives an address that points to an unmodifiable double floating-point data type representing the pounds (lbs) to be converted (provide a meaningful parameter name)
- Receives an address that points to a double floating-point data type representing the conversion result (equivalent kilograms (kg)) – provide a meaningful parameter name
- Receives an address that points to a whole number data type representing the conversion result (equivalent grams (g)) – provide a meaningful parameter name
11. calculateServings
- Returns a double floating-point number
- Receives an unmodifiable whole number representing the serving size in grams
- Receives an unmodifiable whole number representing the total grams for a product
- Receives an address that points to a double floating-point data type representing the calculated result (number of servings)
- Note: This function returns the calculated result in two ways:
o Return value
o Via the pointer argument
12. calculateCostPerServing
- Returns a double floating-point number
- Receives an address to an unmodifiable double floating-point data type representing the product price
- Receives an address to an unmodifiable double floating-point data type representing the total number of servings
- Receives an address to a double floating-point data type representing the calculated result (cost per serving)
- Note: This function returns the calculated result in two ways:
o Return value
o Via the pointer argument
13. calculateCostPerCal
- Returns a double floating-point number
- Receives an address to an unmodifiable double floating-point data type representing the product price
- Receives an address to an unmodifiable double floating-point data type representing the total number of calories
- Receives an address to a double floating-point data type representing the calculated result (cost per calorie)
- Note: This function returns the calculated result in two ways:
o Return value
o Via the pointer argument
14. calculateReportData
- Returns a “ReportData” type
- Receives an unmodifiable “CatFoodInfo” data type representing and item of product data
15. displayReportHeader (this function is provided for you) - Does not return a value nor receive any arguments
16. displayReportData
- Does not return a value
- Receives an unmodifiable “ReportData” data type representing the data to be displayed for a single row in the report
- Receives an unmodifiable whole number representing if the received record is the cheapest product option
17. displayFinalAnalysis
- Does not return a value
- Receives an unmodifiable “CatFoodInfo” data type representing the data of the cheapest product

File w6p2.c (source file)
7. In this file, you will continue to code the function definitions (implementation) for the new functions prototyped in the header file.
8. Include the necessary system and user-defined libraries you need for the application (system libraries use angle brackets (<>), while user-defined use double quotes ("")
9. Use the supplied w6p2.c file comments to help you locate where to insert your code logic Note: Move function #7 (“start”) to the end of the file so it is easy to locate and see how the main logic is implemented
10. Code each function definition implementation based on the prototypes declared in the header file. Below describes each function in a little more detail (numbering continues from the function listing in Part-1 and matches the header file function listing described earlier):
8. convertLbsKg
- This function should convert the received argument representing the pounds value (lbs) to kilograms (kg) by coding the necessary mathematical statement(s)
- Use the macro previously created to help in the conversion (see previous header file section)
- This function must return the converted value in two ways:
o One: by assigning the result to the 2nd pointer argument (only if it is NOT NULL) o Two: by “return”ing the result o Refer to the main.c file to see how this function is “pre-tested”
9. convertLbsG
o One: by assigning the result to the 2nd pointer argument (only if it is NOT NULL) o Two: by “return”ing the result o Refer to the main.c file to see how this function is “pre-tested”
10. convertLbs
- This function should convert the received argument representing the pounds value (lbs) to both, kilograms (kg), and grams (g)
- Use the previously coded functions to perform these needed conversions
Note: return the converted values by assigning the results to the respective pointer argument variables
- Refer to the main.c file to see how this function is “pre-tested”
11. calculateServings
- Using the values supplied in the first two received arguments, code the necessary mathematical statement(s) to derive the total servings
- This function must return the converted value in two ways:
o One: by assigning the result to the 3rd pointer argument (only if it is NOT NULL) o Two: by “return”ing the result
12. calculateCostPerServing
- Using the values supplied in the first two received arguments, code the necessary mathematical statement(s) to derive the cost per serving
- This function must return the converted value in two ways:
o One: by assigning the result to the 3rd pointer argument (only if it is NOT NULL) o Two: by “return”ing the result
13. calculateCostPerCal
- Using the values supplied in the first two received arguments, code the necessary mathematical statement(s) to derive the cost per calorie
- This function must return the converted value in two ways:
o One: by assigning the result to the 3rd pointer argument (only if it is NOT NULL) o Two: by “return”ing the result

14. calculateReportData
- Review the function prototype description in this document to relate the arguments received by this function
- This function must return a ReportData data type, therefore, you will need to create a local variable of this type, assign the required values to it, and return the variable accordingly.
- The ReportData variable you create, will contain the required data for a single record in the analysis report.
- The remaining members of the ReportData variable are calculated values. You should apply the appropriate previously created functions to help you accomplish this.
- All the data required for the calculations is at your disposal either via the 1st argument, or the values already calculated and stored to the ReportData variable
- The last statement in your function should be the returning of the local variable of type ReportData
15. displayReportHeader
- This function definition is provided for you – however, you will need to complete one missing part that substitutes the suggested “serving” size (in grams) as noted in yellow highlighted “???” below. This value should be supplied using one of the macro’s you created (see the header file section).
printf("Analysis Report (Note: Serving = %dg ",
printf("--------------- ");
printf("SKU $Price Bag-lbs Bagprintf("------- ---------- ---------- ---------- ??? );
-g Cal/Serv Servings $/Serv $/Cal ");
--------- -------- -------- ------- ------- ");
kg Bag
16. displayReportData
- This function will display the values of a ReportData type as a formatted row in the report - Use the following formatting and fill-in the missing parts as required:
printf("%07d %10.2lf %10.1lf %10.4lf %9d %8d %8.1lf %7.2lf %7.5lf",...
- Note: If the 2nd argument received by this function is a non-zero value, you must append to the displayed row, a series of three asterisks “***” to indicate that this product has been identified as the cheapest.
17. displayFinalAnalysis
- This function should display the final analysis recommendation message
- Use the argument received by this function to access the required data details
- Also, include a closing message “Happy shopping!”
7. start
- Upgrade this function to include the data analysis component
- You need to create an array variable of type “ReportData” and size it using the appropriate macro defined in the header file – this will be the same size as what was used for the array of “CatFoodInfo” done in Part-1 (be sure to initialize it to a safe empty state)
- You will need to create other local variables to help in the determination of the cheapest product which is based on cost per serving (a calculated value)
- Locate the logic in this function that processes user input for the product data (this should be nested inside an iteration construct). Immediately following that line, add a function call to “calculateReportData” and assign the returned value to the new array you just created (of type ReportData). Hints
o Use the same iterator variable for the index as was used in the assignment of the
CatFoodInfo in the previous statement o Send as the 1st argument to “calculateReportData” the “CatFoodInfo” data just entered by the user
- You must also at some point determine which CatFoodInfo product is the cheapest based on the cost per serving.
o This can be coded in a few places within this function, so you can determine the necessary logic and variables required to accomplish this
o Hint: When you determine which CatFoodInfo product is the cheapest, you will need to store the array index of this product so you can reference the element whenever you need to afterwards/later in the function
- After displaying the CatFoodInfo list of products (the formatted table done in Part-1), display the results of the “ReportData” array in a formatted table. Use the new functions you developed to accomplish this.
- Finally, end the function with a call to the function that displays the final analysis results
(Hint: this is where the saved index from before comes in )
Part-2 Output Example (Note: Use this data for submission)
============================
Pre-testing Helper Functions
============================

------------------------
Function: getIntPositive
------------------------
For each of these tests, enter the following three values (space delimited): -1 0 24
-1 0 24
TEST-1:
ERROR: Enter a positive value: ERROR: Enter a positive value: <PASSED>
-1 0 24
TEST-2:
ERROR: Enter a positive value: ERROR: Enter a positive value: <PASSED>
-1 0 24
TEST-3:
ERROR: Enter a positive value: ERROR: Enter a positive value: <PASSED>
---------------------------
Function: getDoublePositive
---------------------------
For each of these tests, enter the following three values (space delimited): -1 0 82.5


-1 0 82.5
TEST-1:
ERROR: Enter a positive value: ERROR: Enter a positive value: <PASSED>
-1 0 82.5
TEST-2:
ERROR: Enter a positive value: ERROR: Enter a positive value: <PASSED>
-1 0 82.5
TEST-3:
ERROR: Enter a positive value: ERROR: Enter a positive value: <PASSED>
---------------------------
Function: convertLbsKg
---------------------------
Test-1: <PASSED>
Test-2: <PASSED>
Test-3: <PASSED>
--------------------------- Function: convertLbsG
---------------------------
Test-1: <PASSED>
Test-2: <PASSED>
Test-3: <PASSED>
---------------------------
Function: convertLbs
---------------------------
Test-1: <PASSED>

===========================
Starting Main Program Logic
===========================

Cat Food Cost Analysis
======================

Enter the details for 3 dry food bags of product data for analysis. NOTE: A 'serving' is 64g

Cat Food Product #1
--------------------
SKU : 0
12221
ERROR: Enter a positive value:
PRICE : $0
26.99
ERROR: Enter a positive value:
WEIGHT (LBS) : 0
2.5
ERROR: Enter a positive value:
CALORIES/SERV.: 0
325
ERROR: Enter a positive value:

Cat Food Product #2
--------------------
SKU : 34443
PRICE : $71.99
WEIGHT (LBS) : 13.0
CALORIES/SERV.: 325

Cat Food Product #3
--------------------
SKU :
PRICE :
WEIGHT (LBS) : 23332

$ 41.99

5.5
CALORIES/SERV.:


SKU $Price Bag
------- ----------
0012221
0034443
0023332

Analysis Report
---------------
SKU $Price Bag
------- ----------
0012221
0034443
0023332

Final Analysis
--------------
SKU:0034443 Price: $

Happy shopping!
325

-lbs Cal/Serv
---------- --------
26.99 2.5 325 71.99 13.0 325
41.99 5.5 325
Note: Serving = 64g)
-lbs Bag-kg Bag-g Cal/Serv Servings $/Serv $/Cal
---------- ---------- --------- -------- -------- ------- -------
26.99 2.5 1.1340 1133 325 17.7 1.52 0.00469
71.99 13.0 5.8967 5896 325 92.1 0.78 0.00240 ***
41.99 5.5 2.4948 2494 325 39.0 1.08 0.00332
Based on the comparison data, the PURRR-fect economical option is:
71.99

(




Reflection (50%)
Instructions
• Create a text file named “reflect.txt”
• Record your answer in the reflect.txt file for each of the following:

1. Structures data types can demand a lot of memory (for example the "ReportData" structure). Without digging into advanced memory management (for example padding), how many bytes of memory would the "ReportData" structure require? How could we improve the passing of this information to functions? Use the function "displayReportData" from this workshop in your explanation.

2. The CatFoodInfo structure and the ReportData structure contain common members. How could the "ReportData" structure be improved? Show the new and improved "ReportData" structure with your changes, then show how you would modify your code in the function "displayReportData". Specifically, show how you would need to modify the printf statement that displays the data.






Part-2 Submission

1. Upload (file transfer) all source and header files: “main2.c”, “w6p2.h” and “w6p2.c” to your matrix account
2. Upload your reflection file “reflect.txt” to your matrix account (to the same directory)
3. Login to matrix in an SSH terminal and change directory to where you placed your workshop source code.
4. Manually compile and run your program to make sure everything works properly:
gcc -Wall main2.c w6p2.c -o w6 <ENTER>
If there are no error/warnings are generated, execute it: w6 <ENTER>
~profName.proflastname/submit 144w6/NAA_p2 <ENTER>
6. Follow the on-screen submission instructions