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
1,223 questions at Bloomberg · all time
- Kth Largest Element in an ArraymediumArrayDivide and ConquerSortingHeap (Priority Queue)+1frequency 55.6
- Largest Rectangle in HistogramhardArrayStackMonotonic StackRange Minimum/Maximum Queryfrequency 55.0
- Reverse Words in a StringmediumTwo PointersStringfrequency 55.0
- Valid Triangle NumbermediumArrayTwo PointersBinary SearchGreedy+1frequency 55.0
- CandyhardArrayGreedyfrequency 54.4
- Combination SummediumArrayBacktrackingfrequency 54.4
- Isomorphic StringseasyHash TableStringfrequency 54.4
- Merge Strings AlternatelyeasyTwo PointersStringfrequency 54.4
- N-QueenshardArrayBacktrackingAlgorithm Xfrequency 54.4
- Number of ProvincesmediumDepth-First SearchBreadth-First SearchUnion-FindGraph Theoryfrequency 54.4
- Recyclable and Low Fat ProductseasyDatabasefrequency 54.4
- String CompressionmediumTwo PointersStringfrequency 54.4
- Symmetric TreeeasyTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 54.4
- Vertical Order Traversal of a Binary TreehardHash TableTreeDepth-First SearchBreadth-First Search+2frequency 54.4
- Letter Combinations of a Phone NumbermediumHash TableStringBacktrackingfrequency 53.8
- Linked List CycleeasyHash TableLinked ListTwo PointersFloyd's Cycle Finding Algorithmfrequency 53.8
- Reverse StringeasyTwo PointersStringfrequency 53.8
- Rotate ListmediumLinked ListTwo Pointersfrequency 53.8
- Top K Frequent ElementsmediumArrayHash TableDivide and ConquerSorting+4frequency 53.8
- Unique PathsmediumMathDynamic ProgrammingCombinatoricsfrequency 53.8
- Balanced Binary TreeeasyTreeDepth-First SearchBinary Treefrequency 53.1
- Maximum Product SubarraymediumArrayDynamic Programmingfrequency 53.1
- Missing NumbereasyArrayHash TableMathBinary Search+2frequency 53.1
- PermutationsmediumArrayBacktrackingfrequency 53.1
- Regular Expression MatchinghardStringDynamic ProgrammingRecursionfrequency 53.1
- Add BinaryeasyMathStringBit ManipulationSimulationfrequency 52.4
- Intersection of Two ArrayseasyArrayHash TableTwo PointersBinary Search+1frequency 52.4
- Search a 2D MatrixmediumArrayBinary SearchMatrixfrequency 52.4
- Swap Nodes in PairsmediumLinked ListRecursionfrequency 52.4
- Word LadderhardHash TableStringBreadth-First SearchBidirectional Searchfrequency 52.4
- Construct Binary Tree from Preorder and Inorder TraversalmediumArrayHash TableDivide and ConquerTree+1frequency 51.7
- Design A LeaderboardmediumHash TableDesignSortingfrequency 51.7
- Fibonacci NumbereasyMathDynamic ProgrammingRecursionMemoizationfrequency 51.7
- Length of Last WordeasyStringfrequency 51.7
- Remove Nth Node From End of ListmediumLinked ListTwo Pointersfrequency 51.7
- Same TreeeasyTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 51.7
- Valid SudokumediumArrayHash TableMatrixfrequency 51.7
- Count Unhappy FriendsmediumArraySimulationfrequency 51.0
- Edit DistancemediumStringDynamic Programmingfrequency 51.0
- Integer to RomanmediumHash TableMathStringfrequency 51.0
- Jump Game IImediumArrayDynamic ProgrammingGreedyfrequency 51.0
- Longest Increasing SubsequencemediumArrayBinary SearchDynamic ProgrammingLongest Increasing Subsequencefrequency 51.0
- Minimum Size Subarray SummediumArrayBinary SearchSliding WindowPrefix Sumfrequency 51.0
- Split Array Largest SumhardArrayBinary SearchDynamic ProgrammingGreedy+1frequency 51.0
- Add Two Numbers IImediumLinked ListMathStackfrequency 50.2
- Binary Tree Zigzag Level Order TraversalmediumTreeBreadth-First SearchBinary Treefrequency 50.2
- Find the Duplicate NumbermediumArrayTwo PointersBinary SearchBit Manipulation+2frequency 50.2
- Frequency of the Most Frequent ElementmediumArrayBinary SearchGreedySliding Window+2frequency 50.2
- Happy NumbereasyHash TableMathTwo PointersFloyd's Cycle Finding Algorithmfrequency 50.2
- Lexicographical NumbersmediumDepth-First SearchTriefrequency 50.2
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.