Linked Lists, Stacks & Queues
Pointer surgery and the structures built on it.
Linked lists teach the pointer manipulation interviewers love to test, and they're the backbone of stacks and queues. Master traversal and reversal, the fast/slow-pointer trick, and when to reach for a stack (LIFO) or a queue/deque (FIFO).
Lessons in this stage
- 01
Linked List Fundamentals
IntermediateNodes and references, why insertion is O(1) but access is O(n), and the dummy-head trick that removes edge cases.
14 min - 02
Reversing a Linked List
AdvancedThe canonical pointer-surgery problem: re-thread a list in place with three pointers, iteratively and recursively.
15 min - 03
Fast & Slow Pointers
AdvancedOne pointer moving twice as fast as another detects cycles, finds the middle, and locates the nth-from-end in one pass.
15 min - 04
Stacks in Practice
IntermediateLIFO in action: matching brackets, evaluating expressions, and the monotonic stack for next-greater-element problems.
15 min - 05
Queues & Deques
IntermediateFIFO for BFS and scheduling, and the double-ended queue that powers sliding-window-maximum in O(n).
14 min