public class AbbreviatedLinkedList
{
    private Node first;

    /**
     * Constructs an empty linked list.
     */
    public AbbreviatedLinkedList()
    {
        first = null;
    }

    /**
     * Adds an element to the front of the linked list.
     * @param element the element to add
     */
    public void addFirst(Object element)
    {
        Node newNode = new Node();
        newNode.data = element;
        newNode.next = first;
        first = newNode;
    }
    
    /**
     * Internal method to recursively reverse the list.
     * @param p1 the node where to start reversing
     * @return the head node of the reversed list
     */
    private Node reverse(Node p1)
    {
        if ((p1 == null) || (p1.next == null)) return p1;  // base case
        else {
            Node p2 = p1.next;  // one element shorter
            Node p3 = reverse(p2);
            p2.next = p1;       // append first element to reversed list
            p1.next = null;
            return p3;          // head of reversed list
        }
    }
    
    /**
     * Public driver for the recursive reverse method.
     */
    public void reverseRecursive()
    {
        first = reverse(first);
    }
    
    /**
     * Return the linked list as a string.
     */
    public String toString()
    {
        StringBuilder str = new StringBuilder("[");
        Node p = first;
        
        while (p != null) {
            str.append(p.data);
            p = p.next;
            if (p != null) str.append(" ");
        }
        
        str.append("]");
        return str.toString();
    }

    class Node
    {
        public Object data;
        public Node next;
    }
    
    public static void main(String[] args)
    {
        AbbreviatedLinkedList list = new AbbreviatedLinkedList();
        list.addFirst("D");
        list.addFirst("C");
        list.addFirst("B");
        list.addFirst("A");

        System.out.println("       Original list: " + list);
        list.reverseRecursive();
        System.out.println("Recursively reversed: " + list);
    }
}