// Page 238-240

public class StringLinkedList
{
	private ListNode head;
	public StringLinkedList()
	{
		head = null;	// ASCII: 0000 0000
	}

	public void showList()
	{
		ListNode position = head;
		while(position != null)
		{
			System.out.print(position.getData() + " ");
			position = position.getLink();
		}
		System.out.println();
	}
	public int length()
	{
		int count = 0;
		ListNode position = head;
		while(position != null)
		{
			count ++;
			position = position.getLink();
		}
		return count;
	}
	public void addANodeToStart(String addData)
	{
		head = new ListNode(addData, head);
	}
	public void deleteHeadNode()
	{
		if(head != null)
			head = head.getLink();
		else
		{
			System.out.println("Deleting from an empty list.");
			System.exit(0);
		}
	}
	public boolean onList(String target)
	{
		return find(target) != null;
	}
	private ListNode find(String target)
	{
		boolean found = false;
		ListNode position = head;
		while(position != null && !found)
		{
			String dataAtPosition = position.getData();
			if(dataAtPosition.equals(target))
				found = true;
			else
				position = position.getLink();
		}
		return position;
	}
}