juniorLinked Lists
Time complexity of insertion at the beginning?
Updated Apr 28, 2026
Short answer
O(1) because only the head pointer needs to be updated.
Deep explanation
Linked lists are the foundation of dynamic data structures. O(1) because only the head pointer needs to be updated. They provide O(1) insertion at the front, which is superior to O(n) in arrays.
Real-world example
Undo functionality in text editors.
Common mistakes
- Forgetting to handle the case where the list is empty (Null check).
Follow-up questions
- What is the search complexity?