In a doubly linked list, what is the time complexity of deleteNode if you already have a pointer to the node to delete?

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $24.99Unlock all

Master Linked Lists Structures for Data Structures Tests. Utilize flashcards and multiple choice questions with detailed explanations for each, ensuring your readiness for the exam!

Multiple Choice

In a doubly linked list, what is the time complexity of deleteNode if you already have a pointer to the node to delete?

Explanation:
Having a direct pointer to the node to delete lets you unlink it in a constant number of steps. In a doubly linked list each node knows its previous and next neighbors, so you can detach it by re-linking those neighbors: set the previous node’s next to the current node’s next, and set the next node’s prev to the current node’s prev. Then free the current node. If the node is at the head or tail, you update the list’s head or tail accordingly. All of these actions happen in constant time, since you perform a fixed set of pointer updates regardless of the list size. That’s why the operation runs in O(1) time.

Having a direct pointer to the node to delete lets you unlink it in a constant number of steps. In a doubly linked list each node knows its previous and next neighbors, so you can detach it by re-linking those neighbors: set the previous node’s next to the current node’s next, and set the next node’s prev to the current node’s prev. Then free the current node. If the node is at the head or tail, you update the list’s head or tail accordingly. All of these actions happen in constant time, since you perform a fixed set of pointer updates regardless of the list size. That’s why the operation runs in O(1) time.

More Multiple Choice Questions
Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy