[코딩인터뷰] 문제 3.7

문제 3.7

	#region Question 3.7
	/*
	* 먼저 들어온 동물이 먼저 나가는 동물쉼터가 있다고 하자. 쉼터는 개와 고양이만 수용할 수 있다.
	* 사람들은 쉼터의 동물들 가운데 들어온 지 가장 오래된 동물부터 입양할 수 있는데, 개와 고양이 중,
	* 어떤 동물을 데려갈지 선택할 수도 있다. 특정한 동물을 지정해 데려가는 것은 금지되어 있다.
	* (enqueue, dequeueAny, dequeueDog, dequeueCat의 연산을 제공해야 한다.)
	*/
	public class AnimalShelter
	{
	public abstract class Animal : IComparable<Animal>
	{
	public DateTime Time { get; }
	public string Name { get; }
	protected Animal(string name, DateTime time)
	{
	this.Name = name;
	this.Time = time;
	}
	public int CompareTo(Animal other)
	{
	return this.Time.CompareTo(other.Time);
	}
	#region Method Overloading
	public static bool operator >(Animal b1, Animal b2)
	{
	return (b1.CompareTo(b2) > 0);
	}
	public static bool operator <(Animal b1, Animal b2)
	{
	return (b1.CompareTo(b2) < 0);
	}
	#endregion
	}
	public class Cat : Animal
	{
	public Cat(string name, DateTime time) : base(name, time)
	{
	}
	}
	public class Dog : Animal
	{
	public Dog(string name, DateTime time) : base(name, time)
	{
	}
	}
	private Queue<Dog> dogs;
	private Queue<Cat> cats;
	public AnimalShelter()
	{
	this.dogs = new Queue<Dog>();
	this.cats = new Queue<Cat>();
	}
	public void Enqueue(Animal animal)
	{
	switch (animal)
	{
	case Dog d:
	this.dogs.Enqueue(animal as Dog);
	break;
	case Cat c:
	this.cats.Enqueue(animal as Cat);
	break;
	}
	}
	public Animal DequeueAny()
	{
	if(dogs.Count == 0)
	{
	return this.DequeueCat();
	}
	if(cats.Count == 0)
	{
	return this.DequeueDog();
	}
	if(dogs.Peek() < cats.Peek())
	{
	return this.DequeueDog();
	}
	else
	{
	return this.DequeueCat();
	}
	}
	public Animal DequeueCat()
	{
	try
	{
	return this.cats.Dequeue();
	}
	catch (InvalidOperationException)
	{
	return null;
	}
	}
	public Animal DequeueDog()
	{
	try
	{
	return this.dogs.Dequeue();
	}
	catch (InvalidOperationException)
	{
	return null;
	}
	}
	}
	#endregion

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	[TestMethod]
	public void Q3_7()
	{
	var shelter = new StackQueue.AnimalShelter();
	shelter.Enqueue(new StackQueue.AnimalShelter.Cat("A", new DateTime(100)));
	Assert.IsNull(shelter.DequeueDog());
	Assert.AreEqual("A", shelter.DequeueCat().Name);
	shelter.Enqueue(new StackQueue.AnimalShelter.Cat("B", new DateTime(200)));
	Assert.AreEqual("B", shelter.DequeueAny().Name);
	shelter.Enqueue(new StackQueue.AnimalShelter.Dog("C", new DateTime(300)));
	shelter.Enqueue(new StackQueue.AnimalShelter.Cat("D", new DateTime(400)));
	Assert.AreEqual("C", shelter.DequeueAny().Name);
	}

view raw Test_Q3_7.cs hosted with ❤ by GitHub