4 articles
Build an LRU Cache from scratch using a doubly linked list with sentinel nodes and a HashMap for O(1) get and put operations. The most frequently asked hard design problem at Amazon, Microsoft, Google, and Facebook — explained step by step with diagrams.
Implement a browser history data structure with visit, back, and forward operations using a doubly linked list for O(1) navigation. A practical design interview problem at Amazon, Microsoft, and Google that tests your ability to model real-world state with linked list pointers.
LC 432 All O'one Data Structure supports inc, dec, getMaxKey, and getMinKey all in O(1) using a doubly linked list of frequency buckets — one of the most elegant O(1) designs in FAANG interview prep.
LC 430 Flatten a Multilevel Doubly Linked List is a medium interview problem at Microsoft and Amazon that uses DFS or an explicit stack to inline child sub-lists into the main list. Learn the iterative stack approach and the recursive approach with Python and JavaScript, step-by-step dry run, and interview tips.