03-06 - Animal Shelter [Cracking the Coding Interview]

const { LinkedList } = require('../../utils')

const Animal = (() => {
	let order

	class Animal {
		constructor(name) {
			this.name = name
		}

		get order() {
			return order
		}

		setOrder(i) {
			order = i
		}

		isOlderThan(animal) {
			return order < animal.order
		}
	}
	return Animal
})()

class Dog extends Animal {
	constructor(name) {
		super(name)
	}
}

class Cat extends Animal {
	constructor(name) {
		super(name)
	}
}

const AnimalShelter = (() => {
	let dogs = new LinkedList(),
		cats = new LinkedList(),
		order = 0

	class AnimalShelter {
		get size() {
			return dogs.size + cats.size
		}

		enqueue(animal) {
			animal.setOrder(order)
			order++
			if (animal instanceof Dog) {
				dogs.appendToTail(animal)
			} else if (animal instanceof Cat) {
				cats.appendToTail(animal)
			}
		}

		dequeueAny() {
			const dog = this.peekDogs(),
				cat = this.peekCats()

			if (!cat || dog.isOlderThan(cat)) return this.dequeueDogs()
			else {
				return this.dequeueCats()
			}
		}

		dequeueCats() {
			return cats.deleteFromHead()
		}

		dequeueDogs() {
			return dogs.deleteFromHead()
		}

		peekDogs() {
			return dogs.head ? dogs.head.val : null
		}

		peekCats() {
			return cats.head ? cats.head.val : null
		}
	}
	return AnimalShelter
})()

const cat = new Cat('neko')
const cat1 = new Cat('kuro')
const dog = new Dog('hachi')
const dog1 = new Dog('kenta')

const shelter = new AnimalShelter()
shelter.enqueue(cat)
shelter.enqueue(dog)
shelter.enqueue(cat1)
shelter.enqueue(dog1)

console.log('size', shelter.size)
console.log('peekCats: ', shelter.peekCats())

console.log('dequeueAny', shelter.dequeueAny())
console.log('dequeueCats', shelter.dequeueCats())
console.log('dequeueDogs', shelter.dequeueDogs())
console.log('dequeueAny', shelter.dequeueAny())
console.log('dequeueAny', shelter.dequeueAny())
console.log('dequeueDogs', shelter.dequeueDogs())