package LinkedList;

public class Node {

protected Node nextNode;
protected int data;

public Node(int data) {
    this.data = data;
}

}


package LinkedList;

public class LinkedList {

private Node head;

public void insertLast(int data) {

    Node new_node = new Node(data);

    if(head == null) {
        head = new_node;
    }else {

        Node n = head;

        while(n.nextNode != null) {
            n = n.nextNode;
        }

        n.nextNode = new_node;
    }
}

public void insertFirst(int data) {

    Node new_node = new Node(data);

    if(head == null) {

        head = new_node;

    }else {

        Node node = head;
        head = new_node;
        head.nextNode = node;

    }

}

public void insertAt(int index,int data) {

    int x = 1;

    Node node = head;

    while(node != null) {

        if(index == 0) {

            insertFirst(data);
            break;

        }else {

            node = node.nextNode;

            if( index == x ) {

                Node new_node = new Node(data);
                Node current = node;
                node = new_node;
                node.nextNode = current;
                break;
            }

            x++;

        }

    }

}

public void print() {

    Node node = head;

    while(node != null) {
        System.out.println(node.data);
        node = node.nextNode;
    }

}

package Test;

import LinkedList.*;

public class Main {

public static void main(String[] args) {

    LinkedList list = new LinkedList();
    list.insertLast(100);
    list.insertLast(200);
    list.insertLast(300);
    list.insertLast(400);
    list.insertLast(500);

    list.insertAt(1, 50);

    list.print();

}

}