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
- 0003Longest Substring Without Repeating CharactersMed
- 0005Longest Palindromic SubstringMed
- 0013Roman to IntegerEasy
- 00153SumMed
- 0049Group AnagramsMed
- 0121Best Time to Buy and Sell StockEasy
- 0134Gas StationMed
- 0270Move ZeroesEasy
- 0540Reverse Words in a String IIIEasy
- 0601Palindromic SubstringsMed
- 0807Car FleetMed
- 1233Minimum Number of Taps to Open to Water a GardenHard
- 1353Maximum Area of a Piece of Cake After Horizontal and Vertical CutsMed
- 1878Count Vowel Substrings of a StringEasy
- 2246Total Cost to Hire K WorkersMed
- 2395Sum of DistancesMed
- 2573Count Visited Nodes in a Directed GraphHard
- 2591Minimum Number of Groups to Create a Valid AssignmentMed
- 2680Minimize Length of Array Using OperationsMed
Showing 20 of 21