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 31 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 00184SumMed
- 0031Next PermutationMed
- 0072Edit DistanceMed
- 0087Scramble StringHard
- 0146LRU CacheMed
- 0199Design Add and Search Words Data StructureMed
- 0227Sliding Window MaximumHard
- 0288Remove Invalid ParenthesesHard
- 0367Insert Delete GetRandom O(1)Med
- 0513Random Pick with WeightMed
- 0577Task SchedulerMed
- 0699Prefix and Suffix SearchHard
- 0825Minimum Number of Refueling StopsHard
- 1055Building H2OMed
- 1079Snapshot ArrayMed
- 1351Cherry Pickup IIHard
- 1942Stamping the GridHard
- 2049Count Lattice Points Inside a CircleMed
- 2093Design a Text EditorHard
- 2283Design Memory AllocatorMed
Showing 20 of 31