Angela

[AngelaOh]

Stacks and Queues

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Comprehension Questions

Question	Answer
What is an ADT?	An ADT is an abstract data class. It does not specify internal implementation.
Describe a Stack	A Stack is a data structure that operates in a last in first out order.
What are the 5 methods in Stack and what does each do?	Push adds an element to the end of a data structure. Pop removes from the end. Empty? checks if the stack has any elements inside. Peak returns a value but does not remove like pop does. To_s returns the stack in a readable format.
Describe a Queue	A Queue is a data structure that operates in a first in first out order.
What are the 5 methods in Queue and what does each do?	EnQ adds an element to the rear. DeQ removes an element from the front. Front returns the value at the front. Size returns the number of elements inside the queue. Empty checks if the queue contains any elements.
What is the difference between implementing something and using something?	Implementing implies the class knows the inner workings of the action while using something does not necessarily know whats going on under the hood.

OPTIONAL JobSimulation

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

[CheezItMan]

You don't have the postfix problem done, but overall not bad. You do have some issues with the circular buffer. Take a look at my comments and let me know if you have questions.

[CheezItMan]

👍

[CheezItMan]

What about the front wrapping around the array. Instead of @front +=1 you should have @front = (@front + 1) % QUEUE_SIZE

[CheezItMan]

This is less efficient than starting at @front and progressing through the array until you reach @rear, or keeping an instance variable for size.

[CheezItMan]

This assumes @front < @rear, that's not always going to be true.