单链表的基本操作

public class Node{
    public long data;
    public Node next;
    
    public Node(long value){
        this.data = value;
    }
    
    public void display(){
        System.out.println(data+"");
    }
}
//链表操作
public class LinkList{
    private Node first;
    public LinkList(){
        first = null;
    }
    public void insertFirst(long value){
        Node node = new Node(value);
        if(first == null){
            first=node;
        }
        node.next = first.next;
        first = node;
    }
    public Node deleteFirst(){
        Node tmp = first;
        first = tmp.next;
        return tmp;
    }
    public void show(){
        Node current = first;
        while(current!= null){
            current.display();
            current = current.next;
        }
    }
    public Node find(long value){
        Node current = first;
        while(current.data!=value){
            if(current.next==null){
                return null;
            }
            current=current.next;
        }
        return current;
    }
    public Node delete(long value){
        Node current = first;
        Node previous = first;
        while(current.data!=value){
            if(current.next==null){
                return null;
            }
            previos = current;
            current = current.next;
        }
        if(current == first){
            first = first.next;
        }else{
            previous.next = current.next;
        }
        return current;
    }
}