// Removes and returns the CageNode at the front of the Queue.
// If there are no CageNodes in the Queue, throws a NullReferenceException.
public CageNode Dequeue()
{
CageNode dqueued = null;
try
{
if (Front != null)
{
dqueued = Front;
Front = Front.Next;
dqueued.Next = null;
}
else
{
throw new NullReferenceException();
}
}
catch (NullReferenceException)
{
Console.WriteLine("There are no CageNodes in this Queue.");
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
return(dqueued);
}
// Takes in a CageNode and adds it to the end of the Queue.
// If the Queue is empty, this CageNode becomes the new Front and End point for the Queue as its sole member.
public void Enqueue(CageNode cageNode)
{
if (Front == null)
{
Front = cageNode;
End = cageNode;
}
else
{
End.Next = cageNode;
End = cageNode;
}
}
/// <summary>
/// Takes in an Animal object, and checks if it is a Cat or Dog. If it is a Cat or Dog, it places it into a new CageNode with the current
/// serial number, adds the CageNode to the Cats or Dogs Queue respectively, and iterates the NextSerial number, then returns true.
/// If the given Animal isn't a Cat or Dog, does nothing and returns false.
/// </summary>
/// <param name="animal"></param>
/// <returns> Boolean indicating whether given animal was added to the Animal Shelter </returns>
public bool Enqueue(Animal animal)
{
if (animal is Dog)
{
CageNode newCage = new CageNode(animal, NextSerial);
Dogs.Enqueue(newCage);
NextSerial++;
return(true);
}
else if (animal is Cat)
{
CageNode newCage = new CageNode(animal, NextSerial);
Cats.Enqueue(newCage);
NextSerial++;
return(true);
}
else
{
return(false);
}
}
