README.md

Stack + Queue Animal Shelter

Create a class called AnimalShelter which holds only dogs and cats. The shelter operates using a first-in, first-out approach.

Implement the following methods:

enqueue_12 Arguments: animal

• animal can be either a dog or a cat object.
• It must have a species property that is either "cat" or "dog"
• It must have a name property that is a string.

dequeue_12 Arguments: pref

• pref can be either "dog" or "cat"

• Return: either a dog or a cat, based on preference.

• If pref is not "dog" or "cat" then return null.

• This will use code from Queue

Approach & Efficiency

In my code, I created Animal Shelter as a subclass of the class Queue, imported from another module. I used both the inherited methods of enqueue/dequeue from that base class, and new iterations of them as enqueue_12 & dequeue_12. Because I chose to utilize the methods of the base class, it made sense to rename the enqueue & dequeue methods of this challenge.

The dequeue_12 method utilizes Queue.dequeue() and Queue.enqueue() within it, because that covers a lot of the base logic of a generic queue. My logic in dequeue_12 was simply moving the nodes in the shelter_queue to a temp_queue, then reassigning the queues at the end so that the shelter_queue was temp_queue, and then temp_queue is reassigned back to a generic Queue() in that instance of the subclass.

Initially in my draft logic, I kind of merged the original base class and the subclass into one thing. By using the base class methods separately in the new subclass AnimalShelter, I was able to them focus on the logic required to solve the challenge. It only took moving a whole node out but then returning its data.

Time: O(1)

• because only deals with one node at a time for all of these methods, since the nodes being accessed are only at the front of the queue.

Space: O(n)

• with the caveat that the class for Animal Shelter contains two Queue base classes, so in storage it takes 2n.

Solution

Terminal command for general main module: python3 -m stack_queue_animal_shelter.stack_queue_animal_shelter

Terminal command for testing in pytest: python3 -m pytest stack_queue_animal_shelter/

Code Links

Animal Shelter Queue

Tests of Animal Shelter Queue