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 47 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0001Two SumEasy
- 0003Longest Substring Without Repeating CharactersMed
- 0014Longest Common PrefixEasy
- 0020Valid ParenthesesEasy
- 0041First Missing PositiveHard
- 0042Trapping Rain WaterHard
- 0045Jump Game IIMed
- 0048Rotate ImageMed
- 0054Spiral MatrixMed
- 0056Merge IntervalsMed
- 0059Spiral Matrix IIMed
- 0062Unique PathsMed
- 0068Text JustificationHard
- 0084Largest Rectangle in HistogramHard
- 0121Best Time to Buy and Sell StockEasy
- 0128Longest Consecutive SequenceMed
- 0195Course ScheduleMed
- 0196Implement Trie (Prefix Tree)Med
- 0200Word Search IIHard
- 0260Integer to English WordsHard
Showing 20 of 47