public class LinkedQueue<T> implements Queue<T> {
	private LinearNode<T> head = null;
	private LinearNode<T> tail = null;
	private int size = 0;
	
	public void enqueue(T element) {
		if (tail == null){	//O(1)
			head = new LinearNode<T>(element);
			tail = head;
			size++;
		}
		else if (head == tail){	//O(1)
			head.setNext(new LinearNode<T>(element));
			tail = head.getNext();
			size++;
		}
		else{		//O(1)
			tail.setNext(new LinearNode<T>(element));
			tail = tail.getNext();
			size++;
		}
	}

	public T dequeue() {
		if (head == null){   //O(1)
			return null;
		}
		else{		//O(1)
			LinearNode<T> temp = head;
			head = head.getNext();
			size--;
			return temp.getElement();
		}
	}

	@Override
	public T getFront() {	//O(1)
		if (head == null){
			return null;
		}
		else{
			return head.getElement();
		}
	}

	@Override
	public boolean isEmpty() {  //O(1)
		return (head == null);
	}

	public int size() {	//O(1)
		return size;
	}

}