Description

This assignment was locked Oct 6 at 12:33pm.
GOALS OVERVIEW SPECS HINTS REQUIREMENTS SUBMITTING

Learning GOALS
The purpose of this assignment is to continue practice writing C programs and gain more experience working in C, a low-level, non-object oriented language. After completing both parts A and B of this project, you should be comfortable with pointers, arrays, address arithmetic, structures, command-line arguments, and file I/O in C. For part B, you will also be working with structures and file I/O.
OVERVIEW
For this assignment you will be writing the program myMagicSquare.c, which generates a magic square of a specified size and writes it to an output file. A magic square is a matrix of size n x n with positive numbers from 1… n2 arranged such that the numbers in any line (horizontal, vertical, and both main diagonals) sum to the same values. You can read more about magic squares in https://en.wikipedia.org/wiki/Magic_square (https://en.wikipedia.org/wiki/Magic_square)
You’re welcome to develop the solution in two phases. First, code a solution that uses indexing. Once you have that solution working, you can copy and edit to replace the indexing syntax with pointer arithmetic before final testing and submission. You are strongly encouraged to use incremental development to code your solution rather than coding the entire solution followed by debugging that entire code. Incremental development adds code in small increments. After each increment is added, you test the new code to ensure that it works as desired before adding the next increment of code. Bugs are then easier to find since they’re more likely to be in the new code increment rather than the code you’ve already tested.
SPECIFICATIONS
You are to develop your solution using the skeleton code in the file myMagicSquare.c found on the CS Linux computers at:

The program myMagicSquare.c is run as follows:

Where <output_filename> is the name of the file where the generated magic square is to be written. The format of the output file will be as follows (also see example run below):
The first line will contain a positive integer, n, that is the size of the matrix.
Every line after that represents a row in the matrix, starting with the first row. There will be n such lines where each line has n numbers (columns) separated by commas.
Every number in the matrix will be unique.
Siamese Method
Read about the Siamese method (https://en.wikipedia.org/wiki/Siamese_method) (← read the link) to generate the square matrix of an odd size with the numbers 1… n2.
Start by placing 1 at the center column of the topmost row in the square, and then for every number till n2
Move diagonally up-right, by one row and column, and place the next number in that position.
Wrap around to the first column/last row if the move takes you out of the square.
If the next position is already filled with a number then place it one row below the current position.
Alternate Siamese Method
Alternatively, and to make the modular arithmetic easier, you can consider the reflection variant of the above Siamese algorithm by starting from the central row in the last column and then moving in a down-right diagonal fashion. Then, follow the pattern described above.
Finally, the program must write the alternate magic square to the output filename specified in the command line.
The sample runs below show the program’s expected behavior:

HINTS
Using library functions is something you will do a lot when writing programs in C. Each library function is fully specified in a manual page. The man command is very useful for learning the parameters a library function takes, its return value, detailed description, etc. For example, to view the manual page for fopen, you would issue the command “man fopen”. If you are having trouble using man, the same manual pages are also available online. You will need these library functions to write this program. You do not need to use all of these functions since a couple of them are just different ways to do the same thing. We encourage you to refer to our code in the p2A code skeleton for an example of file I/O.
fopen() to open the file. Make sure you specify the correct mode (read or write) for which you are opening the file.
malloc() to allocate memory on the heap free() to free up any dynamically allocated memory fgets() to read each input from a file. fgets can be used to read input from the console as well, in which case the file is stdin, which does not need to be opened or closed. An issue you need to consider is the size of the buffer. Choose a buffer that is reasonably large enough for the input. fscanf()/scanf(): Instead of fgets() you can also use the fscanf()/scanf() to read input from a file or stdin. Since this allows you to read formatted input you might not need to use strtok() to parse the input. fclose() to close the file when done. printf() to display results to the screen. fprintf() to write to a file.
atoi() to convert the input which is read in as a C string into an integer strtok() to tokenize a string on some delimiter. In this program the input file for a square has every row represented as values delimited by a comma. See here
(http://www.tutorialspoint.com/c_standard_library/c_function_strtok.htm) for an example on how to use strtok to tokenize a string.
REQUIREMENTS
Your program must dynamically allocate (i.e., on the heap) the matrix structure and matrix array. Your program must use address arithmetic and dereferencing to access the array representing the matrix.
Your program must use the -> operator when accessing data members of a structure via a pointer variable.
Your programs should operate exactly as the sample run above.
Your program must print error messages exactly as shown in the sample run above, and then call exit(1).
Your program must check the return values for errors of the library functions, malloc(), fopen(), and fclose(). Handle errors by displaying an appropriate error message and then calling exit(1).
Your program must properly free up all dynamically allocated memory at the end of the program.
Your program must close any opened files when it’s done using them.
Your program must follow style guidelines as given in the Style Guide.
Your program must follow commenting guidelines as given in the Commenting Guide.
We will compile your programs with gcc -Wall -m32 -std=gnu99 on the Linux lab machines. So your program must compile there, and without warnings or errors.
SUBMITTING & VERIFYING
SUBMISSION FOR p2B HAS BEEN ENABLED.
1.) Submit only the file listed below under Project p2B in Assignments on Canvas. Do not zip, compress, or submit your file in a folder.
myMagicSquare.c
2.) Verify your submission to ensure it is complete and correct. If not, resubmit all of your work rather than updating just some of the files.
Make sure you have submitted all the files listed above. Forgetting to submit or not submitting one or more of the listed files will result in you losing credit for the assignment.
Make sure the files that you have submitted have the correct contents. Submitting the wrong version of your files, empty files, skeleton files, executable files, corrupted files, or other wrong files will result in you losing credit for the assignment.
Make sure your file names exactly match those listed above. If you resubmit your work, Canvas will modify your file names as mentioned in Repeated Submission above. These Canvas modified names are accepted for grading.

Project p2B
Criteria Ratings Pts
1. Compiles without warnings or errors 6.0 pts
No warnings or errors 3.0 pts
Incorrect output format
Please refer to the project
page on Canvas 0.0 pts
One or more errors or at least 5 warnings 6.0 pts
2. Follows commenting and style guidelines 6.0 to >0.0 pts
Followed 0.0 pts
Not followed 6.0 pts
3. Implements CLA checking 3.0 pts
Meets specifications 2.0 pts
Minor problem
Error message does not match specification 1.0 pts
Major problem
Incorrect argc check, no error message displayed, or does not exit 0.0 pts
Does not check CLAs 3.0 pts
4. Checks return values of malloc() and fopen() 6.0 pts
Checks all 3.0 pts Checks some 0.0 pts Checks none 6.0 pts
5. Closes all opened
files – fclose() 3.0 pts Closed 2.0 pts Some closed 0.0 pts None closed 3.0 pts
Execution test: frees heap memory 6.0 pts
Freed 0.0 pts
Not all freed 6.0 pts
Execution test: size =
3 5.0 pts
Correct result 0.0 pts
Incorrect result 5.0 pts
Execution test: size =
7 5.0 pts
Correct result 0.0 pts
Incorrect result 5.0 pts
Execution test: size =
11 5.0 pts
Correct result 0.0 pts
Incorrect result 5.0 pts
Execution test: size =
13 5.0 pts
Correct result 0.0 pts
Incorrect result 5.0 pts

Criteria R atings Pts
Execution test: size =
17 5.0 pts
Correct result 0.0 pts
Incorrect result 5.0 pts
Execution test: size =
19 5.0 pts
Correct result 0.0 pts
Incorrect result 5.0 pts
Total Points: 60.0