Informatics3-2024/Homework4

Send an email with the solutions as attachments (.c, .cpp or if you have .h and .hpp files) to the following email address: tofihomework+2024info3en@gmail.com

You shouldn't attach the compiled programs. If you feel like you're sending a lot of files (5+) you can put them in a zip, but you don't need to.

LIFO

Implement a LIFO (last-in-first-out) data structure:

• Each "link" should store an integer.
• It should have a push function, that adds a new element at the beginning.
• And a pop function, that removes the first element and returns its stored value.
• Write a main function to test it!

Hints at the end of the page (if you have the time/perseverance, first try to solve it without the help, or just think about how you would solve it).

The data structure is basically the same as the linked list we used on the lecture. The only difference is that this time we're adding elements to the beginning of the list instead of the end. But still we can use a similar structure with a next pointer.

The push will be easier to write compared to the append for linked lists. We don't need to navigate to end of the list this time. We only need to set the start pointer to the new element and set its next pointer to the previous first element. The head of the push function could look something like this:

void push(struct lifo_e **start, int n);

The pop won't be too complex either. The start pointer stores the value to be returned so we just need to store that and its next pointer. Then we can delete it. Don't forget to set the start pointer to the next element before returning the stored value. The head of the pop function could look something like this:

int pop(struct lifo_e **start);