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
15 of 15 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0001Two SumEasy
- 0036Valid SudokuMed
- 0055Jump GameMed
- 0068Text JustificationHard
- 0079Word SearchMed
- 0188Number of IslandsMed
- 0195Course ScheduleMed
- 0198Course Schedule IIMed
- 0200Word Search IIHard
- 0209Maximal SquareMed
- 0370Ransom NoteEasy
- 0765Subdomain Visit CountMed
- 1089Find Words That Can Be Formed by CharactersEasy
- 1475Alert Using Same Key-Card Three or More Times in a One Hour PeriodMed
- 1943Check if Every Row and Column Contains All NumbersEasy
All 15 matching problems loaded