DSA
Master the patterns
Search the bank, then filter by difficulty, pattern, data structure, or algorithm. Each problem includes approaches, solutions, and walkthroughs.
Active·2,723
Easy·667
Medium·1,394
Hard·662
Patterns
Recognize the move
Filter the bank by pattern — each card links into the problem index.
Problem index
Browse problems
Search by title, then refine with facets. Sorted by problem ID.
Difficulty
Facets
20 of 56 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0206The Skyline ProblemHard
- 0208Contains Duplicate IIIHard
- 0302Count of Smaller Numbers After SelfHard
- 0314Count of Range SumHard
- 0339Data Stream as Disjoint IntervalsHard
- 0350Max Sum of Rectangle No Larger Than KHard
- 0443132 PatternMed
- 0480Reverse PairsHard
- 0484Random Point in Non-overlapping RectanglesMed
- 0653Falling SquaresHard
- 0669Range ModuleHard
- 0683My Calendar IMed
- 0685My Calendar IIMed
- 0686My Calendar IIIHard
- 0804Rectangle Area IIHard
- 0809Exam RoomMed
- 0849Maximum Frequency StackHard
- 0929Odd Even JumpHard
- 1252Tweet Counts Per FrequencyMed
- 1312Display Table of Food Orders in a RestaurantMed
Showing 20 of 56