Java

In the following linked list program, create a new method to insert node at head.

provided code:

import java.io.*;

//Java program to implement

//a Singly Linked List

public class LinkedList {

Node head; // head of list

// Linked list Node.

// This inner class is made static

// so that main() can access it

static class Node {

int data;

Node next;

// Constructor

Node(int d)

{

data = d;

next = null;

}

}

// Method to insert a new node

public static LinkedList insert(LinkedList list, int data)

{

// Create a new node with given data

Node new_node = new Node(data);

new_node.next = null;

// If the Linked List is empty,

// then make the new node as head

if (list.head == null) {

list.head = new_node;

}

else {

// Else traverse till the last node

// and insert the new_node there

Node last = list.head;

while (last.next != null) {

last = last.next;

}

// Insert the new_node at last node

last.next = new_node;

}

// Return the list by head

return list;

}

// Method to print the LinkedList.

public static void printList(LinkedList list)

{

Node currNode = list.head;

System.out.print("LinkedList: ");

// Traverse through the LinkedList

while (currNode != null) {

// Print the data at current node

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

// Go to next node

currNode = currNode.next;

}

}

public static LinkedList insertAtHead(LinkedList list, int data) {

// Create a new node with given data

Node new_node = new Node(data);

new_node.next = null;

// If the Linked List is empty,

// then make the new node as head

if (list.head == null) {

list.head = new_node;

}

else {

// Else traverse till the last node

// and insert the new_node there

Node last = list.head;

while (last.next != null) {

last = last.next;

}

// Insert the new_node at last node

last.next = new_node;

}

// Return the list by head

return list;

}

// Driver code

public static void main(String[] args)

{

/* Start with the empty list. */

LinkedList list = new LinkedList();

//

// ******INSERTION******

//

// Insert the values

list = insert(list, 1);

list = insert(list, 2);

list = insert(list, 3);

list = insert(list, 4);

list = insert(list, 5);

list = insert(list, 6);

list = insert(list, 7);

list = insert(list, 8);

// Print the LinkedList

printList(list);

}

}