ต้องการให้ output  node ออกมาเป็นลักษณะนี้

1 , 2 , 3 , 4 , 5
1 , 2 , 3 , ploy , 4 , 5                            
1 , 2 , 3 , ploy , pit , praw , 4 , 5        


***  แทรก node   ploy ตรงกลาง
แทรก nod    pit,praw หลัง ploy






[Spoil] คลิกเพื่อดูข้อความที่ซ่อนไว้public class TestLinkedList {
    
    public MyNode insertAtBeginning(MyNode head, T data){
        MyNode newNode = new MyNode(data);
        if(head == null){
            return newNode;
        }
        newNode.next = head;
        head = newNode;
        return head; //this head will be new head,
    }
    
    public void insertAfter(MyNode previous, T data){
        if(previous == null){
            System.out.print("The given previous node cannot be null.");
            return;
        }
        MyNode newNode = new MyNode(data);
        newNode.next = previous.next;
        previous.next = newNode;
    }
    
    public void PrintOutNode(MyNode one) {
       // int count= 0;
        if(one == null) {
            return;
        }
        MyNode current = one;
        while(current != null){
            System.out.print(current.data + " ");
            current = current.next;
            //count++;
        }
        System.out.println(current);
    }

    public static class MyNode<T>{
        private T data;
        private MyNode<T> next;
        
        public MyNode(T data){
            this.data = data;
            this.next = null;
        }
    }
    
    public static void main(String[] args) {
        MyNode one = new MyNode ("1");
        MyNode two = new MyNode ("2");
        MyNode three = new MyNode ("3");
        MyNode four = new MyNode ("4");
        MyNode five = new MyNode ("5");
        
        one.next = two;
        two.next = three;
        three.next = four;
        four.next = five;
        
        TestLinkedList testLinkedList = new TestLinkedList();
        testLinkedList.PrintOutNode(one);
        testLinkedList.insertAfter(four, null);
        testLinkedList.PrintOutNode(one);
    }
    
}