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
- Sum of Beauty of All SubstringsmediumHash TableStringCountingfrequency 30.2
- Summary RangeseasyArrayfrequency 30.2
- Unique Binary Search TreesmediumMathDynamic ProgrammingTreeBinary Search Tree+1frequency 30.2
- Using a Robot to Print the Lexicographically Smallest StringmediumHash TableStringStackGreedyfrequency 30.2
- All O`one Data StructurehardHash TableLinked ListDesignDoubly-Linked Listfrequency 29.1
- Best Poker HandeasyArrayHash TableCountingfrequency 29.1
- Count Negative Numbers in a Sorted MatrixeasyArrayBinary SearchMatrixfrequency 29.1
- Count Number of Rectangles Containing Each PointmediumArrayHash TableBinary SearchBinary Indexed Tree+1frequency 29.1
- Count Subarrays With Median KhardArrayHash TablePrefix Sumfrequency 29.1
- Design Browser HistorymediumArrayLinked ListStackDesign+2frequency 29.1
- Divide an Array Into Subarrays With Minimum Cost IeasyArraySortingEnumerationfrequency 29.1
- Find All Possible Recipes from Given SuppliesmediumArrayHash TableStringGraph Theory+2frequency 29.1
- Image SmoothereasyArrayMatrixfrequency 29.1
- Interval List IntersectionsmediumArrayTwo PointersSweep Linefrequency 29.1
- Keys and RoomsmediumDepth-First SearchBreadth-First SearchGraph Theoryfrequency 29.1
- Kth Largest Sum in a Binary TreemediumTreeBreadth-First SearchSortingBinary Treefrequency 29.1
- Lemonade ChangeeasyArrayGreedyfrequency 29.1
- Max Sum of a Pair With Equal Sum of DigitsmediumArrayHash TableSortingHeap (Priority Queue)frequency 29.1
- Maximum Number of Books You Can TakehardArrayDynamic ProgrammingStackMonotonic Stackfrequency 29.1
- Maximum Sum With at Most K ElementsmediumArrayGreedySortingHeap (Priority Queue)+1frequency 29.1
- Meeting Rooms IIIhardArrayHash TableSortingHeap (Priority Queue)+1frequency 29.1
- Min Cost to Connect All PointsmediumArrayUnion-FindGraph TheoryMinimum Spanning Tree+3frequency 29.1
- Minimum Operations to Make the Array AlternatingmediumArrayHash TableGreedyCountingfrequency 29.1
- Minimum Swaps to Avoid Forbidden ValueshardArrayHash TableGreedyCountingfrequency 29.1
- Most Stones Removed with Same Row or ColumnmediumHash TableDepth-First SearchUnion-FindGraph Theory+1frequency 29.1
- Number of 1 BitseasyDivide and ConquerBit Manipulationfrequency 29.1
- Number of Equivalent Domino PairseasyArrayHash TableCountingfrequency 29.1
- Number of Students Unable to Eat LuncheasyArrayStackQueueSimulationfrequency 29.1
- Path CrossingeasyHash TableStringfrequency 29.1
- Product Price at a Given DatemediumDatabasefrequency 29.1
- Restore IP AddressesmediumStringBacktrackingfrequency 29.1
- Reverse Words in a String IIIeasyTwo PointersStringfrequency 29.1
- Row With Maximum OneseasyArrayMatrixfrequency 29.1
- Shortest Common SupersequencehardStringDynamic ProgrammingLongest Common Subsequencefrequency 29.1
- Shortest Subarray with Sum at Least KhardArrayBinary SearchQueueSliding Window+3frequency 29.1
- Split Linked List in PartsmediumLinked Listfrequency 29.1
- Sum of All Subset XOR TotalseasyArrayMathBacktrackingBit Manipulation+2frequency 29.1
- Sum of GCD of Formed PairsmediumArrayMathTwo PointersSorting+2frequency 29.1
- Swim in Rising WaterhardArrayBinary SearchDepth-First SearchBreadth-First Search+5frequency 29.1
- Allocate MailboxeshardArrayMathDynamic ProgrammingSortingfrequency 27.8
- Arranging CoinseasyMathBinary Searchfrequency 27.8
- Backspace String CompareeasyTwo PointersStringStackSimulationfrequency 27.8
- Balance a Binary Search TreemediumDivide and ConquerGreedyTreeDepth-First Search+2frequency 27.8
- Baseball GameeasyArrayStackSimulationfrequency 27.8
- Bulb SwitchermediumMathBrainteaserfrequency 27.8
- Combination Sum IIImediumArrayBacktrackingfrequency 27.8
- Construct Smallest Number From DI StringmediumStringBacktrackingStackGreedyfrequency 27.8
- Count Covered BuildingsmediumArrayHash TableSortingfrequency 27.8
- Count Unreachable Pairs of Nodes in an Undirected GraphmediumDepth-First SearchBreadth-First SearchUnion-FindGraph Theoryfrequency 27.8
- Count Zero Request ServersmediumArrayHash TableSliding WindowSortingfrequency 27.8
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.