手动实现LinkedList 的add方法(1)

版权声明： https://blog.csdn.net/weixin_40072979/article/details/82878104

链表的结构就相当于手拉手的游戏；

package com.jianshun;

public class Node {

	Node previous; //上一个节点
	Node next;  //下一个节点
	Object element;  //元素数据
	public Node(Node previous, Node next, Object element) {
		super();
		this.previous = previous;
		this.next = next;
		this.element = element;
	}
	public Node(Object element) {
		super();
		this.element = element;
	}
}

package com.jianshun;

/**
 * 自定义一个链表
 * @author fanfan
 *
 */
public class SxtLinkedList01 {

	private Node first;
	private Node last;
	
	private int size;
	
	//[]
	//['a','b','c']
	public void add(Object obj){
		Node node = new Node(obj);
		
		if(first == null){
			
			node.previous = null;
			node.next = null;
			
			first = node;
			last = node;
		}else{
			node.previous = last;
			node.next = null;
			
			last.next = node; 
			last = node;
		}
	}
	
	@Override
	public String toString() {
		//[a,b,c] first=a, last=c
		StringBuilder sb = new StringBuilder("[");
		Node temp = first;
		while(temp != null){
			sb.append(temp.element+",");
			temp = temp.next;
		}
		sb.setCharAt(sb.length()-1, ']');
		return sb.toString();
	}
	
	
	
	public static void main(String[] args) {
		SxtLinkedList01 list = new SxtLinkedList01();
		
		list.add("a");
		list.add("b");
		list.add("c");
		
		System.out.println(list);
	}
	
	
}