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 80 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0001Two SumEasy
- 0003Longest Substring Without Repeating CharactersMed
- 0004Median of Two Sorted ArraysHard
- 0005Longest Palindromic SubstringMed
- 0006Zigzag ConversionMed
- 0011Container With Most WaterMed
- 00153SumMed
- 0017Letter Combinations of a Phone NumberMed
- 00184SumMed
- 0020Valid ParenthesesEasy
- 0022Generate ParenthesesMed
- 0031Next PermutationMed
- 0033Search in Rotated Sorted ArrayMed
- 0034Find First and Last Position of Element in Sorted ArrayMed
- 0039Combination SumMed
- 0041First Missing PositiveHard
- 0042Trapping Rain WaterHard
- 0046PermutationsMed
- 0049Group AnagramsMed
- 0050Pow(x, n)Med
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