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
2,011 questions at Amazon · all time
- Shortest BridgemediumArrayDepth-First SearchBreadth-First SearchMatrixfrequency 25.1
- Sum of Nodes with Even-Valued GrandparentmediumTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 25.1
- Sum of Root To Leaf Binary NumberseasyTreeDepth-First SearchBinary Treefrequency 25.1
- Ugly NumbereasyMathfrequency 25.1
- Uncrossed LinesmediumArrayDynamic ProgrammingLongest Common Subsequencefrequency 25.1
- Unique Binary Search Trees IImediumDynamic ProgrammingBacktrackingTreeBinary Search Tree+1frequency 25.1
- Valid Triangle NumbermediumArrayTwo PointersBinary SearchGreedy+1frequency 25.1
- 2 Keys KeyboardmediumMathDynamic Programmingfrequency 23.6
- All Elements in Two Binary Search TreesmediumTreeDepth-First SearchBinary Search TreeSorting+1frequency 23.6
- Avoid Flood in The CitymediumArrayHash TableBinary SearchGreedy+1frequency 23.6
- Base 7easyMathStringfrequency 23.6
- Car PoolingmediumArraySortingHeap (Priority Queue)Simulation+1frequency 23.6
- Check for Contradictions in EquationshardArrayStringDepth-First SearchUnion-Find+1frequency 23.6
- Construct Binary Tree from Inorder and Postorder TraversalmediumArrayHash TableDivide and ConquerTree+1frequency 23.6
- Count Beautiful Substrings ImediumHash TableMathStringEnumeration+2frequency 23.6
- Count Number of TextsmediumHash TableMathStringDynamic Programmingfrequency 23.6
- Counting BitseasyDynamic ProgrammingBit Manipulationfrequency 23.6
- Course Schedule IIIhardArrayGreedySortingHeap (Priority Queue)frequency 23.6
- Cut Off Trees for Golf EventhardArrayBreadth-First SearchHeap (Priority Queue)Matrixfrequency 23.6
- Design Linked ListmediumLinked ListDesignfrequency 23.6
- Design a Food Rating SystemmediumArrayHash TableStringDesign+2frequency 23.6
- Design a Text EditorhardLinked ListStringStackDesign+2frequency 23.6
- Distant BarcodesmediumArrayHash TableGreedySorting+2frequency 23.6
- Excel Sheet Column NumbereasyMathStringfrequency 23.6
- Find Distance in a Binary TreemediumHash TableTreeDepth-First SearchBreadth-First Search+3frequency 23.6
- Find Missing ObservationsmediumArrayMathSimulationfrequency 23.6
- Find a Peak Element IImediumArrayBinary SearchMatrixfrequency 23.6
- Find the Prefix Common Array of Two ArraysmediumArrayHash TableBit Manipulationfrequency 23.6
- Game Play Analysis IVmediumDatabasefrequency 23.6
- Game of LifemediumArrayMatrixSimulationfrequency 23.6
- Generate Binary Strings Without Adjacent ZerosmediumStringBacktrackingBit Manipulationfrequency 23.6
- High FiveeasyArrayHash TableSortingHeap (Priority Queue)frequency 23.6
- Insert Delete GetRandom O(1) - Duplicates allowedhardArrayHash TableMathDesign+1frequency 23.6
- K Divisible Elements SubarraysmediumArrayHash TableTrieRolling Hash+2frequency 23.6
- Length of the Longest Valid SubstringhardArrayHash TableStringSliding Windowfrequency 23.6
- Longest Common SubpathhardArrayBinary SearchRolling HashSuffix Array+3frequency 23.6
- Longest Repeating SubstringmediumStringBinary SearchDynamic ProgrammingRolling Hash+4frequency 23.6
- Max Chunks To Make SortedmediumArrayStackGreedySorting+1frequency 23.6
- Max Points on a LinehardArrayHash TableMathGeometry+2frequency 23.6
- Maximize Number of Subsequences in a StringmediumStringGreedyPrefix Sumfrequency 23.6
- Maximize the Profit as the SalesmanmediumArrayHash TableBinary SearchDynamic Programming+1frequency 23.6
- Maximum Alternating Subarray SummediumArrayDynamic Programmingfrequency 23.6
- Maximum Bags With Full Capacity of RocksmediumArrayGreedySortingfrequency 23.6
- Maximum Capacity Within BudgetmediumArrayTwo PointersBinary SearchSortingfrequency 23.6
- Maximum Consecutive Floors Without Special FloorsmediumArraySortingfrequency 23.6
- Maximum Matching of Players With TrainersmediumArrayTwo PointersGreedySortingfrequency 23.6
- Maximum Matrix SummediumArrayGreedyMatrixfrequency 23.6
- Maximum SwapmediumMathGreedyfrequency 23.6
- Minimize Array Sum Using Divisible ReplacementsmediumArrayHash TableMathGreedy+1frequency 23.6
- Minimized Maximum of Products Distributed to Any StoremediumArrayBinary SearchGreedyfrequency 23.6
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.