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
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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
15 of 15 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0001Two SumEasy
- 0005Longest Palindromic SubstringMed
- 0020Valid ParenthesesEasy
- 0021Merge Two Sorted ListsEasy
- 0022Generate ParenthesesMed
- 0039Combination SumMed
- 0053Maximum SubarrayMed
- 0085Maximal RectangleHard
- 0175Largest NumberMed
- 0188Number of IslandsMed
- 0381Decode StringMed
- 063324 GameHard
- 0693Daily TemperaturesMed
- 1560Maximum Binary String After ChangeMed
- 2397Minimum Number of Visited Cells in a GridHard
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