Space - Jessica

[seaweeddol]

Stacks and Queues

Thanks for doing some brain yoga. You are now submitting this assignment!

Comprehension Questions

Question	Answer
What is an ADT?	Abstract data type - a data structure that follows a set of rules/has a set of operations it can perform, but can be implemented with any underlying structure which can be hidden in implementation.
Describe a Stack	A stack can be any data type as long as it follows Last In First Out rules. The first item in will be the last out, and the last item in will be the first out.
What are the 5 methods in Stack and what does each do?	Push - add an item to the top of the stack. Pop - remove an item from the top of a stack. is_empty: returns true if stack is empty or false if not. Peek: returns the top item but does not remove it. Size: returns the number of items in the stack
Describe a Queue	A queue can be any data type and follows First In First Out rules. So the first item in will always be the first item to be removed, then the second, and so on.
What are the 5 methods in Queue and what does each do?	Enqueue: add an item to the back of the queue. Dequeue: remove an item from the front of a queue. is_empty: return true/false depending on if the queue is empty. Front: returns the first item in the queue
What is the difference between implementing something and using something?	Implementing means you create the methods and know how they work in the background. Using something can be done without knowing anything about how the thing works.

OPTIONAL JobSimulation

Question	Answer
Did you include a sample run of your code as a comment?

[CheezItMan]

Nice work Jessica. You hit all the learning goals here. Take a look at my comments and let me know what questions you have.

[CheezItMan]

Just a note that you can dry this up with a hash where they keys are the close braces and the values are the corresponding open braces.

return false if brace_hash[remove] != array.pop

[CheezItMan]

Suggested change

	if (@front == 0 && @rear == (@max_size - 1)) ||
	(@rear == ((@front - 1) % (@max_size - 1)))
	if (@front != -1 && @front == (@rear + 1) % @max_size

[CheezItMan]

This can be dried up with something like

Suggested change

	elsif @front == -1 # Queue is empty
	# initialize front and rear
	@front += 1
	@rear += 1
	elsif (@rear == (@max_size - 1) && @front != 0) # rear needs to wrap around
	@rear = 0
	else
	@rear += 1
	end
	else
	@rear = (@rear + 1) % @max_size
	end

[CheezItMan]

👍

[CheezItMan]

👍

[CheezItMan]

👍 , Nicely done

[CheezItMan]

👍

[CheezItMan]

👍