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Problems
Basics first, then the classics, then company-style assessments. Every problem has tests you run right here; multi-level ones unlock as you go. See the roadmap.
Interview roadmap
Linked lists
Reverse, merge, detect cycles, build an LRU cache.
19 problems
Interview roadmap
Linked lists Reverse, merge, detect cycles, build an LRU cache.
Linked lists guide
- Basics: middle node with fast and slow pointers basics py · c++ · java easy
- Shunt the extra wagons onto a siding py · c++ · java easy
- Reverse Linked List py · c++ · java easy
- Merge Two Sorted Lists py · c++ · java easy
- Remove Nth Node from End of List py · c++ · java easy
- Where does the cycle start? medium
- Reorder List py · c++ · java medium
- Copy List with Random Pointer medium
- Add Two Numbers py · c++ · java medium
- Find the Duplicate Number py · c++ · java medium
- Reverse Nodes in k-Group py · c++ · java hard
- Reverse Linked List II py · c++ · java medium
- Design Circular Queue py · c++ · java medium
LRU / LFU cache guide
- Basics: a recency list (dict + doubly linked list) basics py · c++ · java easy
- Recent files menu py · c++ · java easy
- LRU Cache py · c++ · java medium
- LFU Cache py · c++ · java hard
- LRU, LFU, then a pluggable eviction policy 3 levels Citadel hard
- OA: LRU cache with TTL and weighted size 3 levels Snapchat hard