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
12 of 12 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0020Valid ParenthesesEasy
- 0034Find First and Last Position of Element in Sorted ArrayMed
- 0042Trapping Rain WaterHard
- 0049Group AnagramsMed
- 0146LRU CacheMed
- 0282Find Median from Data StreamHard
- 0287Longest Increasing SubsequenceMed
- 0297Minimum Height TreesMed
- 0381Decode StringMed
- 0425Find All Anagrams in a StringMed
- 0829Koko Eating BananasMed
- 1359Design Browser HistoryMed
All 12 matching problems loaded