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 88 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0017Letter Combinations of a Phone NumberMed
- 0022Generate ParenthesesMed
- 0037Sudoku SolverHard
- 0039Combination SumMed
- 0040Combination Sum IIMed
- 0046PermutationsMed
- 0047Permutations IIMed
- 0051N-QueensHard
- 0052N-Queens IIHard
- 0077CombinationsMed
- 0078SubsetsMed
- 0079Word SearchMed
- 0089Gray CodeMed
- 0090Subsets IIMed
- 0093Restore IP AddressesMed
- 0095Unique Binary Search Trees IIMed
- 0113Path Sum IIMed
- 0126Word Ladder IIHard
- 0131Palindrome PartitioningMed
- 0140Word Break IIHard
Showing 20 of 88