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 182 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0005Longest Palindromic SubstringMed
- 0011Container With Most WaterMed
- 00153SumMed
- 00163Sum ClosestMed
- 00184SumMed
- 0019Remove Nth Node From End of ListMed
- 0026Remove Duplicates from Sorted ArrayEasy
- 0027Remove ElementEasy
- 0028Find the Index of the First Occurrence in a StringEasy
- 0031Next PermutationMed
- 0042Trapping Rain WaterHard
- 0061Rotate ListMed
- 0075Sort ColorsMed
- 0080Remove Duplicates from Sorted Array IIMed
- 0082Remove Duplicates from Sorted List IIMed
- 0086Partition ListMed
- 0088Merge Sorted ArrayEasy
- 0125Valid PalindromeEasy
- 0141Linked List CycleEasy
- 0142Linked List Cycle IIMed
Showing 20 of 182