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 20 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0023Merge k Sorted ListsHard
- 0043Multiply StringsMed
- 0044Wildcard MatchingHard
- 0121Best Time to Buy and Sell StockEasy
- 0200Word Search IIHard
- 0276Game of LifeMed
- 0329Power of FourEasy
- 0336Intersection of Two ArraysEasy
- 0513Random Pick with WeightMed
- 0531Number of ProvincesMed
- 0587Sum of Square NumbersMed
- 0660Design HashMapEasy
- 0872Maximum Sum Circular SubarrayMed
- 1001Longest String ChainMed
- 1111Maximum Subarray Sum with One DeletionMed
- 1183Search Suggestions SystemMed
- 1725Minimum Space Wasted From PackagingHard
- 1867Parallel Courses IIIHard
- 2283Design Memory AllocatorMed
- 2351Minimum Operations to Reduce an Integer to 0Med
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