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 165 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0023Merge k Sorted ListsHard
- 0203Kth Largest Element in an ArrayMed
- 0206The Skyline ProblemHard
- 0227Sliding Window MaximumHard
- 0251Ugly Number IIMed
- 0282Find Median from Data StreamHard
- 0334Top K Frequent ElementsMed
- 0342Design TwitterMed
- 0360Find K Pairs with Smallest SumsMed
- 0365Kth Smallest Element in a Sorted MatrixMed
- 0394Trapping Rain Water IIHard
- 0407Strong Password CheckerHard
- 0438Sort Characters By FrequencyMed
- 0467Sliding Window MedianHard
- 0489IPOHard
- 0493Relative RanksEasy
- 0577Task SchedulerMed
- 0584Course Schedule IIIHard
- 0586Smallest Range Covering Elements from K ListsHard
- 0612Find K Closest ElementsMed
Showing 20 of 165