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 70 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0001Two SumEasy
- 0005Longest Palindromic SubstringMed
- 00184SumMed
- 0023Merge k Sorted ListsHard
- 0031Next PermutationMed
- 0036Valid SudokuMed
- 0037Sudoku SolverHard
- 0045Jump Game IIMed
- 0049Group AnagramsMed
- 0055Jump GameMed
- 0084Largest Rectangle in HistogramHard
- 0113Path Sum IIMed
- 0124Binary Tree Maximum Path SumHard
- 0146LRU CacheMed
- 0164Maximum GapMed
- 0188Number of IslandsMed
- 0195Course ScheduleMed
- 0196Implement Trie (Prefix Tree)Med
- 0197Minimum Size Subarray SumMed
- 0198Course Schedule IIMed
Showing 20 of 70