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Java program to insert a new node at the beginning of the Circular Linked List
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Java program to insert a new node at the beginning of the Circular Linked List
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public class InsertAtStart {
//Represents the node of list.
public class Node{
int data;
Node next;
public Node(int data) {
this.data = data;
}
}
//Declaring head and tail pointer as null.
public Node head = null;
public Node tail = null;
//This function will add the new node at the end of the list.
public void addAtStart(int data){
//Create new node
Node newNode = new Node(data);
//Checks if the list is empty.
if(head == null) {
//If list is empty, both head and tail would point to new node.
head = newNode;
tail = newNode;
newNode.next = head;
}
else {
//Store data into temporary node
Node temp = head;
//New node will point to temp as next node
newNode.next = temp;
//New node will be the head node
head = newNode;
//Since, it is circular linked list tail will point to head.
tail.next = head;
}
}
//Displays all the nodes in the list
public void display() {
Node current = head;
if(head == null) {
System.out.println("List is empty");
}
else {
System.out.println("Adding nodes to the start of the list: ");
do{
//Prints each node by incrementing pointer.
System.out.print(" "+ current.data);
current = current.next;
}while(current != head);
System.out.println();
}
}
public static void main(String[] args) {
InsertAtStart cl = new InsertAtStart();
//Adding 1 to the list
cl.addAtStart(1);
cl.display();
//Adding 2 to the list
cl.addAtStart(2);
cl.display();
//Adding 3 to the list
cl.addAtStart(3);
cl.display();
//Adding 4 to the list
cl.addAtStart(4);
cl.display();
}
}