Java program to insert a new node at the middle of the Circular Linked List
public class InsertInMid {
//Represents the node of list.
public class Node{
int data;
Node next;
public Node(int data) {
this.data = data;
}
}
public int size;
//Declaring head and tail pointer as null.
public Node head = null;
public Node tail = null;
//This function will add the new node to the list.
public void add(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 {
//tail will point to new node.
tail.next = newNode;
//New node will become new tail.
tail = newNode;
//Since, it is circular linked list tail will points to head.
tail.next = head;
}
//Size will count the number of element in the list
size++;
}
//This function will add the new node at the middle of the list.
public void addInMid(int data){
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{
Node temp,current;
//Store the mid-point of the list
int count = (size % 2 == 0) ? (size/2) : ((size+1)/2);
//temp will point to head
temp = head;
current= null;
for(int i = 0; i < count; i++){
//Current will point to node previous to temp.
current = temp;
//Traverse through the list till the middle of the list is reached
temp = temp.next;
}
//current will point to new node
current.next = newNode;
//new node will point to temp
newNode.next = temp;
}
size++;
}
//Displays all the nodes in the list
public void display() {
Node current = head;
if(head == null) {
System.out.println("List is empty");
}
else {
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) {
InsertInMid cl = new InsertInMid();
//Adds data to the list
cl.add(1);
cl.add(2);
cl.add(3);
cl.add(4);
System.out.println("Original list: ");
cl.display();
//Inserting node '5' in the middle
cl.addInMid(5);
System.out.println( "Updated List: ");
cl.display();
//Inserting node '6' in the middle
cl.addInMid(6);
System.out.println("Updated List: ");
cl.display();
}
}
Output:
Original list:
1 2 3 4
Updated List:
1 2 5 3 4
Updated List:
1 2 5 6 3 4
