Data Structures · Question 25 · Medium
Data Structures question 25
In a doubly linked list, you are given a pointer to a node (not the head or the tail) that must be deleted. What is the time complexity of deleting it?
- O(1)
- O(log n)
- O(n log n)
- O(n)
Answer and explanation
Answer: A. O(1)
Explanation: The node already stores pointers to both its neighbours, so you only relink prev->next and next->prev. No traversal is needed, so it takes constant time.
Previous: An undirected simple graph has 6 vertices whose degrees are 3, 3, 2, 2, 2 and… · Next: An array-based binary min-heap holds [2, 5, 3, 9, 6, 4, 8]. One deleteMin…
Practise data structures
Try a fresh set of data structures questions with an explanation after every answer, free and without signing up: Data Structures practice. Or sit a full placement mock test.
More data structures questions
- What is the prefix (Polish) form of the infix expression (A + B) * (C - D) ?
- The keys 12, 22, 35, 42, 55, 7, 17 are inserted into a hash table of size 10…
- An undirected simple graph has 6 vertices whose degrees are 3, 3, 2, 2, 2 and…
- An array-based binary min-heap holds [2, 5, 3, 9, 6, 4, 8]. One deleteMin…
- A binary tree has preorder traversal A B D E H C F G and inorder traversal D B…
- The keys 10, 20, 30, 25, 28 are inserted in that order into an empty AVL tree…
- The numbers 1, 2, 3, 4, 5 are pushed onto a stack in that order, and pops may…
- A max-heap of 15 distinct keys is stored in array positions 1 to 15. How many…
More technical & programming practice
Algorithms · Object-Oriented Programming · DBMS · SQL · Operating Systems · Computer Networks · Software Engineering · Cloud & DevOps
LogicWiz Exams home · All practice topics · Placement mock tests · Daily 10 challenge