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 27 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0001Two SumEasy
- 0003Longest Substring Without Repeating CharactersMed
- 0005Longest Palindromic SubstringMed
- 0011Container With Most WaterMed
- 00153SumMed
- 0020Valid ParenthesesEasy
- 0031Next PermutationMed
- 0033Search in Rotated Sorted ArrayMed
- 0042Trapping Rain WaterHard
- 0079Word SearchMed
- 0122Best Time to Buy and Sell Stock IIMed
- 0128Longest Consecutive SequenceMed
- 0142Linked List Cycle IIMed
- 0151Reverse Words in a StringMed
- 0153Find Minimum in Rotated Sorted ArrayMed
- 0155Min StackMed
- 0175Largest NumberMed
- 0194Reverse Linked ListEasy
- 0226Product of Array Except SelfMed
- 0430String CompressionMed
Showing 20 of 27