O(1)时间删除链表中节点

class doDelete{
    static class LNode {
        int data;
        LNode next;
        public  LNode(int data){
            this.data = data;
        }
    }    
    LNode head;
    LNode current;
    public void add(int data){
        if(head==null){
            head = new LNode(data);
            current=head;
        }else{
            current.next=new LNode(data);
            current = current.next;
        }
    }
    public void print(LNode node){
        LNode temp = node;
        if(temp == null) return;
        while(temp!=null){
            System.out.println(temp.data);
            temp = temp.next;
        }
    }
    public LNode delete(LNode head,LNode node){
        if(head==null || node  == null) return null;
        if(node.next != null){
            LNode temp = node.next;
            node.data = temp.data;
            node.next = temp.next;
            return head;
        }else if (head == node){
            return null;
        }else{
            LNode temp = head;
            while(temp.next!=node){
                temp = temp.next;
            }
            temp.next = null;
            return head;
        }
         
    }
    public static void main(String[] args){
        //doDelete r = new doDelete();
        //for(int i =1;i<10;i++){
        //    r.add(i);
        //}
        //r.print(r.head);
        //删除头结点为空
        LNode head = null;
        doDelete r = new doDelete();
//        LNode result = r.delete(head,head);
//        r.print(result);
        
        //删除尾节点不为空
        //for(int i=1;i<10;i++){
        //    r.add(i);
        //}        
        //r.print(r.head);
        //System.out.println();
        //LNode result = r.delete(r.head,r.head.next);
        //r.print(r.head);
        
        //删除尾节点为空，只有一个节点
        // head = new LNode(3);
        //r.print(head);
        //System.out.println("--------------");
        //LNode result = r.delete(head,head);
        //r.print(result);
        
        //删除尾节点，>一个节点
        for(int i=1;i<10;i++){
            r.add(i);
        }
        LNode temp = new LNode(10);
        r.current.next = temp;
        r.print(r.head);
        System.out.println("---------------");
        r.delete(r.head,temp);
        r.print(r.head);
        
        
    }
    

}