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 21 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0001Two SumEasy
- 0011Container With Most WaterMed
- 00153SumMed
- 0041First Missing PositiveHard
- 0042Trapping Rain WaterHard
- 0049Group AnagramsMed
- 0084Largest Rectangle in HistogramHard
- 0114Flatten Binary Tree to Linked ListMed
- 0121Best Time to Buy and Sell StockEasy
- 0146LRU CacheMed
- 0175Largest NumberMed
- 0209Maximal SquareMed
- 0224Lowest Common Ancestor of a Binary TreeMed
- 0446Repeated Substring PatternEasy
- 0449Minimum Moves to Equal Array Elements IIMed
- 0481Target SumMed
- 0689Asteroid CollisionMed
- 0948Rotting OrangesMed
- 1213Deepest Leaves SumMed
- 1334Minimum Time to Collect All Apples in a TreeMed
Showing 20 of 21