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 23 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0003Longest Substring Without Repeating CharactersMed
- 0076Minimum Window SubstringHard
- 0091Decode WaysMed
- 0109Convert Sorted List to Binary Search TreeMed
- 0126Word Ladder IIHard
- 0128Longest Consecutive SequenceMed
- 0148Sort ListMed
- 0155Min StackMed
- 0196Implement Trie (Prefix Tree)Med
- 0226Product of Array Except SelfMed
- 0291Range Sum Query 2D - ImmutableMed
- 0352Water and Jug ProblemMed
- 0430String CompressionMed
- 0586Smallest Range Covering Elements from K ListsHard
- 0689Asteroid CollisionMed
- 0912Check Completeness of a Binary TreeMed
- 0935Time Based Key-Value StoreMed
- 0948Rotting OrangesMed
- 1037Car PoolingMed
- 1209Maximum Candies You Can Get from BoxesHard
Showing 20 of 23