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 41 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0003Longest Substring Without Repeating CharactersMed
- 0010Regular Expression MatchingHard
- 0044Wildcard MatchingHard
- 0049Group AnagramsMed
- 0062Unique PathsMed
- 0063Unique Paths IIMed
- 0074Search a 2D MatrixMed
- 0078SubsetsMed
- 0115Distinct SubsequencesHard
- 0139Word BreakMed
- 0146LRU CacheMed
- 0188Number of IslandsMed
- 0195Course ScheduleMed
- 0203Kth Largest Element in an ArrayMed
- 0212Basic CalculatorHard
- 0215Basic Calculator IIMed
- 0227Sliding Window MaximumHard
- 0228Search a 2D Matrix IIMed
- 0282Find Median from Data StreamHard
- 0321Increasing Triplet SubsequenceMed
Showing 20 of 41