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
- Department Highest SalarymediumDatabasefrequency 27.8
- Design an Expression Tree With Evaluate FunctionmediumArrayMathStackTree+2frequency 27.8
- Find the CelebritymediumTwo PointersGraph TheoryInteractivefrequency 27.8
- Find the Highest AltitudeeasyArrayPrefix Sumfrequency 27.8
- Flatten Nested List IteratormediumStackTreeDepth-First SearchDesign+2frequency 27.8
- HeatersmediumArrayTwo PointersBinary SearchSortingfrequency 27.8
- How Many Numbers Are Smaller Than the Current NumbereasyArrayHash TableSortingCounting Sortfrequency 27.8
- IPOhardArrayGreedySortingHeap (Priority Queue)frequency 27.8
- Last Stone WeighteasyArrayHeap (Priority Queue)frequency 27.8
- Maximum Erasure ValuemediumArrayHash TableSliding Windowfrequency 27.8
- Maximum Length of Pair ChainmediumArrayDynamic ProgrammingGreedySorting+1frequency 27.8
- Meeting RoomseasyArraySortingQuicksortfrequency 27.8
- Minimum Cost For TicketsmediumArrayDynamic Programmingfrequency 27.8
- Move Pieces to Obtain a StringmediumTwo PointersStringfrequency 27.8
- N-Queens IIhardBacktrackingAlgorithm Xfrequency 27.8
- Number of Operations to Make Network ConnectedmediumDepth-First SearchBreadth-First SearchUnion-FindGraph Theoryfrequency 27.8
- Number of Recent CallseasyDesignQueueData Streamfrequency 27.8
- Palindrome Partitioning IIhardStringDynamic Programmingfrequency 27.8
- Partition Array Such That Maximum Difference Is KmediumArrayGreedySortingfrequency 27.8
- Partition to K Equal Sum SubsetsmediumArrayDynamic ProgrammingBacktrackingBit Manipulation+2frequency 27.8
- Pascal's Triangle IIeasyArrayDynamic Programmingfrequency 27.8
- Recover a Tree From Preorder TraversalhardStringTreeDepth-First SearchBinary Treefrequency 27.8
- Redundant ConnectionmediumDepth-First SearchBreadth-First SearchUnion-FindGraph Theoryfrequency 27.8
- Remove Covered IntervalsmediumArraySortingfrequency 27.8
- Shortest PalindromehardStringRolling HashString MatchingHash Function+3frequency 27.8
- Shortest Path in a Grid with Obstacles EliminationhardArrayBreadth-First SearchMatrixfrequency 27.8
- Strictly Palindromic NumbermediumMathTwo PointersBrainteaserfrequency 27.8
- Subtree of Another TreeeasyTreeDepth-First SearchString MatchingBinary Tree+1frequency 27.8
- Super Washing MachineshardArrayGreedyfrequency 27.8
- The Number of the Smallest Unoccupied ChairmediumArrayHash TableHeap (Priority Queue)frequency 27.8
- Actors and Directors Who Cooperated At Least Three TimeseasyDatabasefrequency 26.5
- Battleships in a BoardmediumArrayDepth-First SearchMatrixfrequency 26.5
- Best Time to Buy and Sell Stock IVhardArrayDynamic Programmingfrequency 26.5
- Binary Tree Vertical Order TraversalmediumHash TableTreeDepth-First SearchBreadth-First Search+2frequency 26.5
- Build Array from PermutationeasyArraySimulationfrequency 26.5
- Can Make Arithmetic Progression From SequenceeasyArraySortingfrequency 26.5
- Check If Digits Are Equal in String After Operations IeasyMathStringSimulationCombinatorics+1frequency 26.5
- Clone Binary Tree With Random PointermediumHash TableTreeDepth-First SearchBreadth-First Search+1frequency 26.5
- Continuous Subarray SummediumArrayHash TableMathPrefix Sum+1frequency 26.5
- Count Number of Pairs With Absolute Difference KeasyArrayHash TableCountingfrequency 26.5
- Count the Number of Special Characters IeasyHash TableStringfrequency 26.5
- Cousins in Binary Tree IImediumHash TableTreeDepth-First SearchBreadth-First Search+1frequency 26.5
- Delete and EarnmediumArrayHash TableDynamic Programmingfrequency 26.5
- Design File SystemmediumHash TableStringDesignTriefrequency 26.5
- Design Hit CountermediumArrayBinary SearchDesignQueue+1frequency 26.5
- Design Memory AllocatormediumArrayHash TableDesignSimulationfrequency 26.5
- Determine Whether Matrix Can Be Obtained By RotationeasyArrayMatrixfrequency 26.5
- Exchange SeatsmediumDatabasefrequency 26.5
- Find Common CharacterseasyArrayHash TableStringfrequency 26.5
- Find Minimum Time to Finish All JobshardArrayDynamic ProgrammingBacktrackingBit Manipulation+1frequency 26.5
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.