CSE 333 25sp Exercise 4

out: Wednesday, April 9, 2025
due: Friday, April 11, 2025 by 10:00 am, No late exercises accepted.

Goals: Write a multi-file C program that properly uses header, implementation, and client files to partition a program.

Description: Your job is to write a multi-file C program. You should write the following three files:

• NthPrime.h: a header file, containing a single function prototype declaration for a function called NthPrime(), as well as comments above the prototype documenting how to use the function. The function should accept a single int16_t parameter, and it should return an int64_t. The function should return the nth prime number, where n is the function's parameter. The function call NthPrime(1) should return 2, NthPrime(2) should return 3, NthPrime(3) should return 5, and so on. The result of NthPrime(n) is not defined if n <= 0, and implementations do not need to check for this possibility.
  
• NthPrime.c: a file containing the implementation of NthPrime. Feel free to use the simplest possible primality testing algorithm (hint: "x is not prime if it is divisible by ..."). You may also want to define some helper functions here as well.
  
• ex4.c: a file containing a main() function that tests NthPrime by printing the input and output output of NthPrime for at least two different, non-trivial arguments (but you do not need to print an enormous number of test cases - keep it reasonable).

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Your code must:

• compile without errors or warnings on CSE Linux machines (lab workstations, attu, or current CSE home VM)
• have no crashes, memory leaks, or memory errors on CSE linux machines
• be contained in the three files described above. We will compile your code with the following commands (and you should too):

  bash$ gcc -Wall -g -std=c17 -c -o NthPrime.o NthPrime.c
  bash$ gcc -Wall -g -std=c17 -c -o ex4.o ex4.c
  bash$ gcc -Wall -g -std=c17 -o ex4 ex4.o NthPrime.o

  Do not submit a Makefile.
• be pretty: the formatting, modularization, variable and function names, and so on must make us smile rather than cry. (You should follow the Google C++ Style guide. Suggestion: cpplint --clint.) Since we haven't talked about to header guards or static functions in class yet, you should ignore any warnings about these for this exercise (only), and you do not need to include them.
• be robust: you should think about handling bogus input from the user, and you should handle hard-to-handle cases (if there are any) gracefully.
• have a comment at the top of each of your files with your name and CSE or UW email address.

You should submit your exercise using the Gradescope dropbox linked on the course resources web page.