Delete a Node from Circular Linked List in DSA C - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a circular linked list?

A circular linked list is a linked list where the last node points back to the first node, forming a circle without a null end.

intermediate

Why is deleting a node from a circular linked list different from a singly linked list?

Because the last node points back to the head, we must update the last node's next pointer if the head is deleted to maintain the circle.

beginner

In deleting a node from a circular linked list, what happens if the list has only one node?

Deleting the only node makes the list empty, so the head pointer becomes NULL.

intermediate

What is the general approach to delete a node with a given key in a circular linked list?

1. Find the node with the key.<br>2. If it's the head, update the last node's next pointer.<br>3. Remove the node by linking its previous node to its next node.<br>4. Free the deleted node.

beginner

What should you do if the node to delete is not found in the circular linked list?

No changes are made; the list remains the same because the key does not exist.

What does the last node in a circular linked list point to?

A The first node

B NULL

C Itself

D The previous node

In a circular linked list, the last node points back to the first node to form a circle.

When deleting the head node in a circular linked list, what must be updated?

A The tail pointer

B The last node's next pointer

C Nothing needs to be updated

D The head's previous pointer

The last node's next pointer must point to the new head to maintain the circular structure.

If a circular linked list has only one node and it is deleted, what is the new state of the list?

A List with two nodes

B List with one node pointing to itself

C Empty list (head is NULL)

D List remains unchanged

Deleting the only node empties the list, so the head becomes NULL.

What happens if the node to delete is not found in the circular linked list?

A The head node is deleted

B The last node is deleted

C The list becomes empty

D The list remains unchanged

If the key is not found, no deletion occurs and the list stays the same.

Which pointer is used to traverse a circular linked list during deletion?

A A temporary pointer starting at head

B A pointer starting at NULL

C A pointer starting at the last node

D No pointer is needed

A temporary pointer starting at head is used to find the node to delete.

Explain step-by-step how to delete a node with a given key from a circular linked list.

Think about how the circle is maintained after deletion.

Describe the special cases to consider when deleting nodes from a circular linked list.

Focus on how the list structure changes in these cases.