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
- New 21 GamemediumMathDynamic ProgrammingSliding WindowProbability and Statisticsfrequency 20.0
- Nth Magical NumberhardMathBinary SearchLeast Common MultipleInclusion-Exclusion Principlefrequency 20.0
- Number of AtomshardHash TableStringStackSortingfrequency 20.0
- Number of Calls Between Two PersonsmediumDatabasefrequency 20.0
- Number of Days in a MontheasyMathfrequency 20.0
- Number of Sets of K Non-Overlapping Line SegmentsmediumMathDynamic ProgrammingCombinatoricsPrefix Sumfrequency 20.0
- Number of Submatrices That Sum to TargethardArrayHash TableMatrixPrefix Sumfrequency 20.0
- Number of Times a Driver Was a PassengermediumDatabasefrequency 20.0
- Number of Unique CategoriesmediumUnion-FindInteractiveCountingfrequency 20.0
- Number of Visible People in a QueuehardArrayStackMonotonic Stackfrequency 20.0
- Number of Ways to Arrive at DestinationmediumDynamic ProgrammingGraph TheoryTopological SortShortest Path+1frequency 20.0
- Numbers At Most N Given Digit SethardArrayMathStringBinary Search+1frequency 20.0
- Pairs of Songs With Total Durations Divisible by 60mediumArrayHash TableCountingfrequency 20.0
- Parallel Courses IIIhardArrayDynamic ProgrammingGraph TheoryTopological Sort+1frequency 20.0
- Populating Next Right Pointers in Each Node IImediumLinked ListTreeDepth-First SearchBreadth-First Search+1frequency 20.0
- Power of FoureasyMathBit ManipulationRecursionfrequency 20.0
- Primary Department for Each EmployeeeasyDatabasefrequency 20.0
- Prime ArrangementseasyMathPrimality TestSieve TheoryPrime Number Sievefrequency 20.0
- Prime Number of Set Bits in Binary RepresentationeasyMathBit ManipulationPrimality Testfrequency 20.0
- Product Sales Analysis IIeasyDatabasefrequency 20.0
- Product Sales Analysis VeasyDatabasefrequency 20.0
- Product's Price for Each StoreeasyDatabasefrequency 20.0
- Products With Three or More Orders in Two Consecutive YearsmediumDatabasefrequency 20.0
- Pseudo-Palindromic Paths in a Binary TreemediumBit ManipulationTreeDepth-First SearchBreadth-First Search+1frequency 20.0
- Queries on a Permutation With KeymediumArrayBinary Indexed TreeSimulationSqrt Decompositionfrequency 20.0
- Rearrange Characters to Make Target StringeasyHash TableStringCountingfrequency 20.0
- Rearrange Products TableeasyDatabasefrequency 20.0
- Relocate MarblesmediumArrayHash TableSortingSimulationfrequency 20.0
- Remove Duplicates from Sorted List IImediumLinked ListTwo Pointersfrequency 20.0
- Remove Vowels from a StringeasyStringfrequency 20.0
- Return Length of Arguments Passedeasyfrequency 20.0
- Reverse String PrefixeasyTwo PointersStringfrequency 20.0
- Sales Analysis IeasyDatabasefrequency 20.0
- Sales Analysis IIeasyDatabasefrequency 20.0
- Search in a Binary Search TreeeasyTreeBinary Search TreeBinary Treefrequency 20.0
- Separate Squares ImediumArrayBinary Searchfrequency 20.0
- Sequentially Ordinal Rank TrackerhardDesignHeap (Priority Queue)Data StreamOrdered Setfrequency 20.0
- Sliding Window MedianhardArrayHash TableSliding WindowHeap (Priority Queue)+1frequency 20.0
- Sort Features by PopularitymediumArrayHash TableStringSortingfrequency 20.0
- Soup ServingsmediumMathDynamic ProgrammingProbability and Statisticsfrequency 20.0
- Split BSTmediumTreeBinary Search TreeRecursionBinary Treefrequency 20.0
- Stone Game IImediumArrayMathDynamic ProgrammingMinimax+3frequency 20.0
- Students With Invalid DepartmentseasyDatabasefrequency 20.0
- Subarrays Distinct Element Sum of Squares IIhardArrayHash TableBinary Indexed TreeSegment Treefrequency 20.0
- Successful Pairs of Spells and PotionsmediumArrayTwo PointersBinary SearchSortingfrequency 20.0
- Sum of Digits in the Minimum NumbereasyArrayMathfrequency 20.0
- Sum of Number and Its ReversemediumMathEnumerationfrequency 20.0
- Sum of Scores of Built StringshardStringBinary SearchRolling HashSuffix Array+4frequency 20.0
- Sum of Square NumbersmediumMathTwo PointersBinary Searchfrequency 20.0
- Threshold Majority QuerieshardArrayHash TableBinary SearchDivide and Conquer+2frequency 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.