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 39 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0011Container With Most WaterMed
- 00153SumMed
- 0032Longest Valid ParenthesesHard
- 0041First Missing PositiveHard
- 0042Trapping Rain WaterHard
- 0073Set Matrix ZeroesMed
- 0075Sort ColorsMed
- 0084Largest Rectangle in HistogramHard
- 0121Best Time to Buy and Sell StockEasy
- 0146LRU CacheMed
- 0149Max Points on a LineHard
- 0284Serialize and Deserialize Binary TreeHard
- 0341Russian Doll EnvelopesHard
- 0367Insert Delete GetRandom O(1)Med
- 0455Validate IP AddressMed
- 0524Single Element in a Sorted ArrayMed
- 0531Number of ProvincesMed
- 0641Longest Univalue PathMed
- 0689Asteroid CollisionMed
- 0717Partition LabelsMed
Showing 20 of 39