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 515 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0002Add Two NumbersMed
- 0007Reverse IntegerMed
- 0009Palindrome NumberEasy
- 0012Integer to RomanMed
- 0013Roman to IntegerEasy
- 0029Divide Two IntegersMed
- 0043Multiply StringsMed
- 0048Rotate ImageMed
- 0050Pow(x, n)Med
- 0060Permutation SequenceHard
- 0062Unique PathsMed
- 0066Plus OneEasy
- 0067Add BinaryEasy
- 0069Sqrt(x)Easy
- 0070Climbing StairsEasy
- 0089Gray CodeMed
- 0096Unique Binary Search TreesMed
- 0149Max Points on a LineHard
- 0150Evaluate Reverse Polish NotationMed
- 0166Fraction to Recurring DecimalMed
Showing 20 of 515