CSE 333 25au Exercise 3

out: Wednesday, October 1, 2025
due: Friday, October 3, 2025 by 10:00 am, No late exercises accepted.

Goals: Write a program that uses structs, typedef, and dynamic memory allocation (malloc/free).

Description: Your job is to write a C program that does the following:

• uses typedef to define a new structured type called Point3d, which contains uint16_t fields for x, y, and z coordinates.
• defines a function called AllocatePoint3d that accepts three uint16_t values as arguments, mallocs space for a Point3d, assigns those three arguments to the x, y, and z fields, and returns (a pointer to) the malloc'ed Point3d.
• has a main() that "tests" AllocatePoint3d. For the purposes of this exercise, it is enough for you to write code that simply allocates a struct by calling AllocatePoint3d and verifies that the struct members contain the correct values. Your "test" should print an appropriate message if something is wrong; if all is well your program should terminate silently. Make sure your main function frees any memory that AllocatePoint3d allocates. Hint: Don't make assumptions about what AllocatePoint3d does, even though you implement it. Imagine that your main is testing an implementation of AllocatePoint3d that is implemented by another programmer.

Note: we will be using valgrind to test whether your code has a memory leak! (You probably should too...)

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Your code must:

• compile without errors or warnings on CSE Linux machines (lab workstations, attu, or CSE home VM)
• have no crashes, memory leaks, or memory errors on CSE linux machines
• be contained in a single file called ex3.c that compiles with the command gcc -Wall -g -std=c17 -o ex3 ex3.c -- do not submit a Makefile.
• be pretty: the formatting, modularization, variable and function names, and so on must make us smile rather than cry.
• be robust: you should think about handling bogus input from the user (if any), and you should handle hard-to-handle cases (if there are any) gracefully.
• have a comment at the top of your .c file 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.