insertion.

Insertion into a Circular Singly Linked List
Algorithm Overview:

Circular Property: In a circular linked list, the last node always points back to the first node (the head), making the list circular.
Insertion at the End: This algorithm inserts a new node at the end of the list while maintaining the circular nature.
Steps:

Create a new node:

Dynamically allocate memory for a new node.
Assign the data value to the node.
Set the new node’s next pointer to the head (since it will eventually point to the first node in a circular list).
Handle the empty list case:

If the list is empty (i.e., *head == NULL), the new node becomes the head.
Since it’s the only node, its next should point to itself, ensuring the circular nature.
Handle the non-empty list case:

If the list already has nodes, traverse the list until you reach the last node (i.e., the node whose next is pointing to the head).
Set the last node’s next to the new node.
Set the new node’s next to the head, keeping the circular property intact.