Doubly Linked List
1 problems · 1 with full explanations
0 Easy0 Medium0 Hard
A doubly linked list has both prev and next pointers, enabling O(1) insertion/deletion at any known node. It underlies LRU Cache, browser history, and undo stacks. In C#, LinkedList<T> is a doubly linked list with O(1) AddFirst/AddLast/Remove(node).
How to practice
To practice Doubly Linked List problems effectively, start with the Easy problems listed below, trace through each solution on paper, then re-implement without looking. When you can recognise the doubly linked list pattern within 30 seconds of reading a new problem, move on to Medium difficulty. Use the related topic pages and our study guide for a structured progression.