Java单链表（双端链表）简单实现

1、节点数据结构

public class LinkNode {
    public int data;
    public LinkNode next;

    public LinkNode(){

    }

    public LinkNode(int value){
        this.data = value;
        this.next = null;
    }
}

2、单链表实现

public class SingleLink {

    public LinkNode head;

    public SingleLink(){
        head = new LinkNode();
        head.next = null;
    }

    public void insertFirst(int value){
        LinkNode newLink = new LinkNode(value);
        if(head.next == null){
            head.next = newLink;
        } else {
            LinkNode temp = head.next;
            head.next = newLink;
            newLink.next = temp;
        }
    }

    public int deleteFirst(){
        if(isEmpty())
            throw new EmptyLinkException("current link is empty");
        LinkNode temp = head.next;
        head.next = head.next.next;
        return temp.data;
    }

    public LinkNode find(int value){
        if(isEmpty())
            throw new EmptyLinkException("current link is empty");
        LinkNode temp = head.next;
        while(temp != null){
            if(value == temp.data){
                break;
            }
            temp = temp.next;
        }

        return temp;
    }

    public void displayLink(){
        LinkNode temp = head.next;
        while(temp != null){
            System.out.println(temp.data);
            temp = temp.next;
        }
    }

    public boolean isEmpty(){
        return (head.next == null);
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        Random random = new Random();
        SingleLink singleLink = new SingleLink();
        for(int i=0;i<10;i++){
            singleLink.insertFirst(random.nextInt(100));
        }
        singleLink.displayLink();
        int temp = random.nextInt(100);
        System.out.println("try to find: " + temp);
        System.out.println(singleLink.find(temp) == null?"not found":singleLink.find(temp).data);
        for(int i=0;i<10;i++){
            System.out.println(singleLink.deleteFirst());
        }
    }
}

3、注意
（1）双端链表是在单链表基础上增加一个对链表最后一个节点的引用
（2）双端链表可以增加一个insertLast方法
（3）双端链表【不能】解决从链表末端删除节点的问题

双向链表可以在头部和尾部进行节点【添加】和【删除】操作