package com.shine.test.datastruct;

/**

 * 简易链表

 *

 * @author SHINE

 *

 * @param <E>

 */

public class LinkList<E> {

	private Node head, tail;

	private int size = 0;

	protected class Node<E> {

		E data;

		Node next;

	}

	public LinkList() {

		head = new Node();

		head.next = null;

		tail = new Node<E>();

	}

	public void insert(E e, int index) {

		Node newNode = new Node<E>();

		newNode.data = e;

		Node before = head;

		Node temp = head.next;

		while (index >= 0) {

			if (index == 0) {

				before.next = newNode;

				newNode.next = temp;

				size++;

				break;

			}

			before = temp;

			temp = temp.next;

			index--;

		}

	}

	public void add(E e) {

		Node node = new Node();

		node.data = e;

		node.next = null;

		if (head.next == null) {

			head.next = node;

		}

		tail.next = node;

		tail = node;

		size++;

	}

	public E get(int index) {

		if (index > size - 1) {

			return null;

		}

		Node temp = head.next;

		while (index >= 0) {

			if (index == 0) {

				return (E) temp.data;

			}

			temp = temp.next;

			index--;

		}

		return null;

	}

	public E getFirst() {

		return get(0);

	}

	public E getLast() {

		return get(size - 1);

	}

	public void remove(E e) {

		Node before = head;

		Node temp = head.next;

		while (temp != null) {

			if (temp.data.equals(e)) {

				before.next = temp.next;

				size--;

				break;

			}

			before = temp;

			temp = temp.next;

		}

	}

	@Override

	public String toString() {

		StringBuffer sb = new StringBuffer();

		Node temp = head.next;

		while (temp != null) {

			sb.append(temp.data + "->");

			temp = temp.next;

		}

		return sb.toString();

	}

	public int getLength() {

		return size;

	}

}