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 38 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0017Letter Combinations of a Phone NumberMed
- 0034Find First and Last Position of Element in Sorted ArrayMed
- 0037Sudoku SolverHard
- 0038Count and SayMed
- 0039Combination SumMed
- 0043Multiply StringsMed
- 0063Unique Paths IIMed
- 0188Number of IslandsMed
- 0196Implement Trie (Prefix Tree)Med
- 0269Expression Add OperatorsHard
- 0282Find Median from Data StreamHard
- 0309Coin ChangeMed
- 0319Reconstruct ItineraryHard
- 0334Top K Frequent ElementsMed
- 0379Is SubsequenceEasy
- 0397Split Array Largest SumHard
- 0430String CompressionMed
- 0481Target SumMed
- 0524Single Element in a Sorted ArrayMed
- 0586Smallest Range Covering Elements from K ListsHard
Showing 20 of 38