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 23 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0001Two SumEasy
- 0003Longest Substring Without Repeating CharactersMed
- 00153SumMed
- 0042Trapping Rain WaterHard
- 0046PermutationsMed
- 0121Best Time to Buy and Sell StockEasy
- 0125Valid PalindromeEasy
- 0179Rotate ArrayMed
- 0230Valid AnagramEasy
- 0246Add DigitsEasy
- 1124Ugly Number IIIMed
- 1143Maximum Equal FrequencyHard
- 1169Reconstruct a 2-Row Binary MatrixMed
- 1402Find a Value of a Mysterious Function Closest to TargetHard
- 1512Minimum Deletions to Make Character Frequencies UniqueMed
- 1625Equal Sum Arrays With Minimum Number of OperationsMed
- 2006Maximize the Topmost Element After K MovesMed
- 2076Percentage of Letter in StringEasy
- 2111Maximum XOR After Operations Med
- 2260Minimum Fuel Cost to Report to the CapitalMed
Showing 20 of 23