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
298 questions at Apple · all time
- Reorder ListmediumLinked ListTwo PointersStackRecursionfrequency 35.0
- Sort ColorsmediumArrayTwo PointersSortingQuicksort+1frequency 35.0
- Validate IP AddressmediumStringfrequency 35.0
- Word Ladder IIhardHash TableStringBacktrackingBreadth-First Search+1frequency 35.0
- 4SummediumArrayTwo PointersSortingfrequency 29.5
- Apple Redistribution into BoxeseasyArrayGreedySortingfrequency 29.5
- Basic CalculatorhardMathStringStackRecursionfrequency 29.5
- Best Poker HandeasyArrayHash TableCountingfrequency 29.5
- Best Time to Buy and Sell Stock IVhardArrayDynamic Programmingfrequency 29.5
- Binary Tree Right Side ViewmediumTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 29.5
- Binary Tree Vertical Order TraversalmediumHash TableTreeDepth-First SearchBreadth-First Search+2frequency 29.5
- Contains DuplicateeasyArrayHash TableSortingfrequency 29.5
- Continuous Subarray SummediumArrayHash TableMathPrefix Sum+1frequency 29.5
- Design Browser HistorymediumArrayLinked ListStackDesign+2frequency 29.5
- Design Task ManagermediumHash TableDesignHeap (Priority Queue)Ordered Setfrequency 29.5
- Employee Free TimehardArraySweep LineSortingHeap (Priority Queue)frequency 29.5
- Evaluate Reverse Polish NotationmediumArrayMathStackfrequency 29.5
- Find All Anagrams in a StringmediumHash TableStringSliding Windowfrequency 29.5
- Find Largest Value in Each Tree RowmediumTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 29.5
- Find Minimum in Rotated Sorted ArraymediumArrayBinary Searchfrequency 29.5
- Find Pivot IndexeasyArrayPrefix Sumfrequency 29.5
- Find the CelebritymediumTwo PointersGraph TheoryInteractivefrequency 29.5
- House RobbermediumArrayDynamic Programmingfrequency 29.5
- Intersection of Two ArrayseasyArrayHash TableTwo PointersBinary Search+1frequency 29.5
- Intersection of Two Linked ListseasyHash TableLinked ListTwo Pointersfrequency 29.5
- Interval List IntersectionsmediumArrayTwo PointersSweep Linefrequency 29.5
- Is Graph Bipartite?mediumDepth-First SearchBreadth-First SearchUnion-FindGraph Theory+2frequency 29.5
- Island PerimetereasyArrayDepth-First SearchBreadth-First SearchMatrixfrequency 29.5
- Jump Game IImediumArrayDynamic ProgrammingGreedyfrequency 29.5
- K Closest Points to OriginmediumArrayMathDivide and ConquerGeometry+4frequency 29.5
- Logger Rate LimitereasyHash TableDesignData Streamfrequency 29.5
- Longest Substring with At Most K Distinct CharactersmediumHash TableStringSliding Windowfrequency 29.5
- Maximum Product of Three NumberseasyArrayMathSortingfrequency 29.5
- Maximum SwapmediumMathGreedyfrequency 29.5
- Minimum Knight MovesmediumBreadth-First SearchHeuristic SearchBidirectional SearchA* Searchfrequency 29.5
- My Calendar IImediumArrayBinary SearchDesignSegment Tree+2frequency 29.5
- Next Greater Element IImediumArrayStackMonotonic Stackfrequency 29.5
- Parse Lisp ExpressionhardHash TableStringStackRecursionfrequency 29.5
- Paths in Matrix Whose Sum Is Divisible by KhardArrayDynamic ProgrammingMatrixfrequency 29.5
- Permutations IImediumArrayBacktrackingSortingfrequency 29.5
- Random Pick with WeightmediumArrayMathBinary SearchPrefix Sum+1frequency 29.5
- Read N Characters Given read4 II - Call Multiple TimeshardArraySimulationInteractivefrequency 29.5
- Remove ElementeasyArrayTwo Pointersfrequency 29.5
- Robot Bounded In CirclemediumMathStringSimulationfrequency 29.5
- Same TreeeasyTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 29.5
- Search a 2D MatrixmediumArrayBinary SearchMatrixfrequency 29.5
- Short Encoding of WordsmediumArrayHash TableStringTriefrequency 29.5
- Shortest Path in Binary MatrixmediumArrayBreadth-First SearchMatrixfrequency 29.5
- Shortest Word DistanceeasyArrayStringfrequency 29.5
- Sudoku SolverhardArrayHash TableBacktrackingMatrix+2frequency 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.