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
15 of 15 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0034Find First and Last Position of Element in Sorted ArrayMed
- 0035Search Insert PositionEasy
- 0036Valid SudokuMed
- 0044Wildcard MatchingHard
- 0056Merge IntervalsMed
- 0065Valid NumberHard
- 0121Best Time to Buy and Sell StockEasy
- 0200Word Search IIHard
- 0422Non-overlapping IntervalsMed
- 0439Minimum Number of Arrows to Burst BalloonsMed
- 0931Squares of a Sorted ArrayEasy
- 0935Time Based Key-Value StoreMed
- 1256Maximum Number of Events That Can Be AttendedMed
- 1559Average Waiting TimeMed
- 1943Check if Every Row and Column Contains All NumbersEasy
All 15 matching problems loaded