Java program to delete a node from the beginning of the Circular Linked List

In this program, we will create a circular linked list and delete a node from the beginning of the list. If the list is empty, print the message "List is empty". If the list is not empty, we will make the head to point to next node in the list, i.e., we will delete the first node.

Circular linked list after deleting node from beginning.

Here, A represents the head of the list. We need to delete a node from the beginning of the list. So, we will remove A such that B will become new head and tail will point to the new head.

Algorithm

• Define a Node class which represents a node in the list. It has two properties data and next which will point to the next node.
• Define another class for creating the circular linked list and it has two nodes: head and tail. It has two methods: deleteStart() and display() .
• deleteStart() will delete the node from the beginning of the list:
  • It first checks whether the head is null (empty list) then, it will return from the function as there is no node present in the list.
  • If the list is not empty, it will check whether list has only one node.
  • If the list has only one node, it will set both head and tail to null.
  • If the list has more than one node then, the head will point to the next node in the list that is, we will remove the previous head node and tail will point to the new head.

a. display() will show all the nodes present in the list.

• Define a new node 'current' that will point to the head.
• Print current.data till current will points to head again.
• Current will point to the next node in the list in each iteration.

Program:

Output:

Original List: 
 1 2 3 4
Updated List: 
 2 3 4
Updated List: 
 3 4
Updated List: 
 4
Updated List: 
List is empty