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
175 questions at LinkedIn · all time
- User Purchase PlatformhardDatabasefrequency 44.7
- Validate Stack SequencesmediumArrayStackSimulationfrequency 44.7
- Number of Connected Components in an Undirected GraphmediumDepth-First SearchBreadth-First SearchUnion-FindGraph Theoryfrequency 42.2
- Max Area of IslandmediumArrayDepth-First SearchBreadth-First SearchUnion-Find+1frequency 39.4
- Paint House IIhardArrayDynamic Programmingfrequency 39.4
- Valid Triangle NumbermediumArrayTwo PointersBinary SearchGreedy+1frequency 39.4
- Design HashMapeasyArrayHash TableLinked ListDesign+1frequency 36.1
- Longest Valid ParentheseshardStringDynamic ProgrammingStackBracket Sequencesfrequency 36.1
- Min StackmediumStackDesignfrequency 36.1
- Reverse Words in a StringmediumTwo PointersStringfrequency 36.1
- Shuffle an ArraymediumArrayMathDesignRandomizedfrequency 36.1
- Smallest Range Covering Elements from K ListshardArrayHash TableGreedySliding Window+2frequency 36.1
- Valid Parenthesis StringmediumStringDynamic ProgrammingStackGreedy+1frequency 36.1
- Cinema Seat AllocationmediumArrayHash TableGreedyBit Manipulationfrequency 32.1
- Closest Leaf in a Binary TreemediumTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 32.1
- Combination Sum IImediumArrayBacktrackingfrequency 32.1
- Delete Node in a BSTmediumTreeBinary Search TreeBinary Treefrequency 32.1
- Implement Rand10() Using Rand7()mediumMathRejection SamplingRandomizedProbability and Statisticsfrequency 32.1
- Integer to RomanmediumHash TableMathStringfrequency 32.1
- Is Graph Bipartite?mediumDepth-First SearchBreadth-First SearchUnion-FindGraph Theory+2frequency 32.1
- LFU CachehardHash TableLinked ListDesignDoubly-Linked Listfrequency 32.1
- Longest Substring Without Repeating CharactersmediumHash TableStringSliding Windowfrequency 32.1
- Number of Divisible Triplet SumsmediumArrayHash Tablefrequency 32.1
- Process Tasks Using ServersmediumArrayHeap (Priority Queue)frequency 32.1
- Same TreeeasyTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 32.1
- Word Ladder IIhardHash TableStringBacktrackingBreadth-First Search+1frequency 32.1
- 01 MatrixmediumArrayDynamic ProgrammingBreadth-First SearchMatrixfrequency 26.9
- Best Meeting PointhardArrayMathSortingMatrixfrequency 26.9
- Combination SummediumArrayBacktrackingfrequency 26.9
- Course SchedulemediumDepth-First SearchBreadth-First SearchGraph TheoryTopological Sort+1frequency 26.9
- Dot Product of Two Sparse VectorsmediumArrayHash TableTwo PointersDesign+1frequency 26.9
- House Robber IImediumArrayDynamic Programmingfrequency 26.9
- Invert Binary TreeeasyTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 26.9
- K Closest Points to OriginmediumArrayMathDivide and ConquerGeometry+4frequency 26.9
- Koko Eating BananasmediumArrayBinary Searchfrequency 26.9
- Making A Large IslandhardArrayDepth-First SearchBreadth-First SearchUnion-Find+1frequency 26.9
- Maximize Sum of Weights after Edge RemovalshardDynamic ProgrammingTreeDepth-First SearchSortingfrequency 26.9
- Merge Sorted ArrayeasyArrayTwo PointersSortingfrequency 26.9
- Minimum Knight MovesmediumBreadth-First SearchHeuristic SearchBidirectional SearchA* Searchfrequency 26.9
- Open the LockmediumArrayHash TableStringBreadth-First Search+1frequency 26.9
- Reorder ListmediumLinked ListTwo PointersStackRecursionfrequency 26.9
- Reverse IntegermediumMathfrequency 26.9
- Rotting OrangesmediumArrayBreadth-First SearchMatrixfrequency 26.9
- Subarray Sum Equals KmediumArrayHash TablePrefix Sumfrequency 26.9
- Task SchedulermediumArrayHash TableGreedySorting+2frequency 26.9
- Unique PathsmediumMathDynamic ProgrammingCombinatoricsfrequency 26.9
- Word BreakmediumArrayHash TableStringDynamic Programming+3frequency 26.9
- All Nodes Distance K in Binary TreemediumHash TableTreeDepth-First SearchBreadth-First Search+1frequency 20.0
- Convert to Base -2mediumMathfrequency 20.0
- Expression Add OperatorshardMathStringBacktrackingfrequency 20.0
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.