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
11 of 11 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0002Add Two NumbersMed
- 0005Longest Palindromic SubstringMed
- 0025Reverse Nodes in k-GroupHard
- 0091Decode WaysMed
- 0162Find Peak ElementMed
- 0287Longest Increasing SubsequenceMed
- 0627Number of Longest Increasing SubsequenceMed
- 0708Reach a NumberMed
- 1700Rotating the BoxMed
- 1878Count Vowel Substrings of a StringEasy
- 2110Count Unreachable Pairs of Nodes in an Undirected GraphMed
All 11 matching problems loaded