package LL;

public class LL1 {

Node head;

private int size;

LL1(){

this.size = 0;

}

public static void main(String[] args) {

LL1 list = new LL1();

list.addFirst("a");

list.addFirst("ab");

list.addLast("zzzz");

list.printall();

//list.deleteFirst();

//list.printall();

//System.out.println(list.getSize());

list.head = list.reverse(list.head);

list.printall();

}

public static Node reverse(Node head){

if (head == null || head.next==null)

return head;

Node newHead = reverse(head.next);

head.next.next = head;

head.next = null;

return newHead;

/*Node current = head;

Node previous = null;

Node next = null;

while(current != null){

next = current.next;

current.next = previous;

previous = current;

current = next;

}

return previous;*/

}

public int getSize(){

return size;

}

public void deleteFirst(){

if (head == null){

System.out.print("list is empty");

return;

}

size--;

head = head.next;

}

public void deleteLast(){

if (head == null){

System.out.print("list is empty");

return;

}

size--;

if (head.next == null){

head = null;

return;

}

Node secondLast = head;

Node lastNode = head;

while(lastNode.next != null){

lastNode = lastNode.next;

secondLast = secondLast.next;

}

secondLast.next = null;

}

public void addLast(String data){

Node newNode = new Node(data);

//Node head = null;

if (head == null){

head = newNode;

return;

}

Node currNode = head;

while (currNode.next != null){

currNode = currNode.next;

}

currNode.next = newNode;

}

public void printall(){

if (head == null){

System.out.print("no list");

}

Node currNode= head;

while (currNode != null){

System.out.print(currNode.data+"-->");

currNode =currNode.next;

}

System.out.print("nulll");

System.out.println();

}

public void addFirst(String data){

Node newNode = new Node(data);

//Node head = null;

if (head == null){

head = newNode;

return;

}

newNode.next= head;

head = newNode;

}

class Node{

String data;

Node next;

Node(String data){

this.data = data;

this.next = next;

size++;

}

}

}