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 89 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0005Longest Palindromic SubstringMed
- 0014Longest Common PrefixEasy
- 0022Generate ParenthesesMed
- 0041First Missing PositiveHard
- 0042Trapping Rain WaterHard
- 0045Jump Game IIMed
- 0049Group AnagramsMed
- 0055Jump GameMed
- 0056Merge IntervalsMed
- 0057Insert IntervalMed
- 0075Sort ColorsMed
- 0084Largest Rectangle in HistogramHard
- 0102Binary Tree Level Order TraversalMed
- 0121Best Time to Buy and Sell StockEasy
- 0122Best Time to Buy and Sell Stock IIMed
- 0123Best Time to Buy and Sell Stock IIIHard
- 0127Word LadderHard
- 0128Longest Consecutive SequenceMed
- 0134Gas StationMed
- 0135CandyHard
Showing 20 of 89