Problems
Callback's own problems and the LeetCode questions companies have been asking, in one place — filter by category, company, topic, difficulty, and how recently a question showed up.
Asked on LeetCode
1,399 questions at Meta · all time
- Meeting RoomseasyArraySortingQuicksortfrequency 33.0
- Minimum Cost For TicketsmediumArrayDynamic Programmingfrequency 33.0
- Path Sum IImediumBacktrackingTreeDepth-First SearchBinary Treefrequency 33.0
- Rearrange Array Elements by SignmediumArrayTwo PointersSimulationfrequency 33.0
- Reverse PairshardArrayBinary SearchDivide and ConquerBinary Indexed Tree+4frequency 33.0
- Strobogrammatic Number IImediumArrayStringRecursionfrequency 33.0
- The MazemediumArrayDepth-First SearchBreadth-First SearchMatrixfrequency 33.0
- Two Sum IV - Input is a BSTeasyHash TableTwo PointersTreeDepth-First Search+3frequency 33.0
- Average Selling PriceeasyDatabasefrequency 31.9
- Customer Who Visited but Did Not Make Any TransactionseasyDatabasefrequency 31.9
- Defanging an IP AddresseasyStringfrequency 31.9
- Evaluate Reverse Polish NotationmediumArrayMathStackfrequency 31.9
- Excel Sheet Column TitleeasyMathStringfrequency 31.9
- Intersection of Two Linked ListseasyHash TableLinked ListTwo Pointersfrequency 31.9
- Is Graph Bipartite?mediumDepth-First SearchBreadth-First SearchUnion-FindGraph Theory+2frequency 31.9
- Monthly Transactions ImediumDatabasefrequency 31.9
- Number of ProvincesmediumDepth-First SearchBreadth-First SearchUnion-FindGraph Theoryfrequency 31.9
- Ransom NoteeasyHash TableStringCountingfrequency 31.9
- Russian Doll EnvelopeshardArrayBinary SearchDynamic ProgrammingSorting+1frequency 31.9
- Subtree of Another TreeeasyTreeDepth-First SearchString MatchingBinary Tree+1frequency 31.9
- Surrounded RegionsmediumArrayDepth-First SearchBreadth-First SearchUnion-Find+1frequency 31.9
- Binary Tree CamerashardDynamic ProgrammingTreeDepth-First SearchBinary Tree+1frequency 30.7
- Check If Two String Arrays are EquivalenteasyArrayStringfrequency 30.7
- Construct Binary Tree from Preorder and Inorder TraversalmediumArrayHash TableDivide and ConquerTree+1frequency 30.7
- Convert Sorted Array to Binary Search TreeeasyArrayDivide and ConquerTreeBinary Search Tree+1frequency 30.7
- Customers Who Never OrdereasyDatabasefrequency 30.7
- Fruit Into BasketsmediumArrayHash TableSliding Windowfrequency 30.7
- House Robber IImediumArrayDynamic Programmingfrequency 30.7
- Min Cost Climbing StairseasyArrayDynamic Programmingfrequency 30.7
- Non-overlapping IntervalsmediumArrayDynamic ProgrammingGreedySortingfrequency 30.7
- Number of Recent CallseasyDesignQueueData Streamfrequency 30.7
- Running Sum of 1d ArrayeasyArrayPrefix Sumfrequency 30.7
- Sort an ArraymediumArrayDivide and ConquerSortingHeap (Priority Queue)+4frequency 30.7
- Students and ExaminationseasyDatabasefrequency 30.7
- Sudoku SolverhardArrayHash TableBacktrackingMatrix+2frequency 30.7
- The Skyline ProblemhardArrayDivide and ConquerBinary Indexed TreeSegment Tree+4frequency 30.7
- Add to Array-Form of IntegereasyArrayMathfrequency 29.5
- Employees Earning More Than Their ManagerseasyDatabasefrequency 29.5
- Fizz BuzzeasyMathStringSimulationfrequency 29.5
- Implement Stack using QueueseasyStackDesignQueuefrequency 29.5
- Largest Divisible SubsetmediumArrayMathDynamic ProgrammingSortingfrequency 29.5
- Maximal SquaremediumArrayDynamic ProgrammingMatrixfrequency 29.5
- Minimum Path SummediumArrayDynamic ProgrammingMatrixfrequency 29.5
- Minimum Time Visiting All PointseasyArrayMathGeometryfrequency 29.5
- Rank Transform of an ArrayeasyArrayHash TableSortingfrequency 29.5
- Single Number IImediumArrayBit Manipulationfrequency 29.5
- Stickers to Spell WordhardArrayHash TableStringDynamic Programming+4frequency 29.5
- TrianglemediumArrayDynamic Programmingfrequency 29.5
- Triangle JudgementeasyDatabasefrequency 29.5
- User Activity for the Past 30 Days IeasyDatabasefrequency 29.5
Listings only — titles, difficulty, and tags link out to LeetCode. Imported from the leetcode-company-wise-problems snapshot dated 1 June 2025. Frequency is that dataset's own relative score within a company and time range.