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
18 of 18 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0005Longest Palindromic SubstringMed
- 0014Longest Common PrefixEasy
- 0020Valid ParenthesesEasy
- 0022Generate ParenthesesMed
- 0033Search in Rotated Sorted ArrayMed
- 0049Group AnagramsMed
- 0056Merge IntervalsMed
- 0070Climbing StairsEasy
- 0092Reverse Linked List IIMed
- 0146LRU CacheMed
- 0188Number of IslandsMed
- 0226Product of Array Except SelfMed
- 0230Valid AnagramEasy
- 0370Ransom NoteEasy
- 0543Subarray Sum Equals KMed
- 0649Max Area of IslandMed
- 1130Remove All Adjacent Duplicates in String IIMed
- 1720Egg Drop With 2 Eggs and N FloorsMed
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