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
- Number of Unique Subjects Taught by Each TeachereasyDatabasefrequency 15.7
- Ones and ZeroesmediumArrayStringDynamic ProgrammingKnapsack Problem+1frequency 15.7
- Optimal Account BalancinghardArrayDynamic ProgrammingBacktrackingBit Manipulation+1frequency 15.7
- Partition Array for Maximum SummediumArrayDynamic Programmingfrequency 15.7
- Process String with Special Operations IIhardStringSimulationfrequency 15.7
- Project Employees IeasyDatabasefrequency 15.7
- Range Product Queries of PowersmediumArrayBit ManipulationPrefix Sumfrequency 15.7
- Remove Invalid ParentheseshardStringBacktrackingBreadth-First Searchfrequency 15.7
- Reveal Cards In Increasing OrdermediumArrayQueueSortingSimulationfrequency 15.7
- Richest Customer WealtheasyArrayMatrixfrequency 15.7
- Root Equals Sum of ChildreneasyTreeBinary Treefrequency 15.7
- Score of a StringeasyStringfrequency 15.7
- Separate Squares IIhardArrayBinary SearchSegment TreeSweep Linefrequency 15.7
- Sequential DigitsmediumEnumerationfrequency 15.7
- Shortest Distance from All BuildingshardArrayBreadth-First SearchMatrixfrequency 15.7
- Shortest Unsorted Continuous SubarraymediumArrayTwo PointersStackGreedy+2frequency 15.7
- Shortest Word DistanceeasyArrayStringfrequency 15.7
- Solving Questions With BrainpowermediumArrayDynamic Programmingfrequency 15.7
- Sort Array by Increasing FrequencyeasyArrayHash TableSortingfrequency 15.7
- Split a String in Balanced StringseasyStringGreedyCountingfrequency 15.7
- Step-By-Step Directions From a Binary Tree Node to AnothermediumStringTreeDepth-First SearchBinary Tree+2frequency 15.7
- Sum of Absolute Differences in a Sorted ArraymediumArrayMathPrefix Sumfrequency 15.7
- The k-th Lexicographical String of All Happy Strings of Length nmediumStringBacktrackingfrequency 15.7
- Valid Tic-Tac-Toe StatemediumArrayMatrixfrequency 15.7
- Verifying an Alien DictionaryeasyArrayHash TableStringfrequency 15.7
- Ways to Express an Integer as Sum of PowersmediumDynamic Programmingfrequency 15.7
- Word SubsetsmediumArrayHash TableStringfrequency 15.7
- Zero Array Transformation ImediumArrayPrefix Sumfrequency 15.7
- All Ancestors of a Node in a Directed Acyclic GraphmediumDepth-First SearchBreadth-First SearchGraph TheoryTopological Sort+1frequency 13.2
- All Possible Full Binary TreesmediumDynamic ProgrammingTreeRecursionMemoization+1frequency 13.2
- Arithmetic SlicesmediumArrayDynamic ProgrammingSliding Windowfrequency 13.2
- Array Prototype Lasteasyfrequency 13.2
- Best Meeting PointhardArrayMathSortingMatrixfrequency 13.2
- Best Sightseeing PairmediumArrayDynamic Programmingfrequency 13.2
- Best Time to Buy and Sell Stock VmediumArrayDynamic Programmingfrequency 13.2
- Best Time to Buy and Sell Stock with Transaction FeemediumArrayDynamic ProgrammingGreedyfrequency 13.2
- Biggest Single NumbereasyDatabasefrequency 13.2
- Binary Tree Level Order Traversal IImediumTreeBreadth-First SearchBinary Treefrequency 13.2
- Binary WatcheasyBacktrackingBit Manipulationfrequency 13.2
- Buddy StringseasyHash TableStringfrequency 13.2
- Check If a String Contains All Binary Codes of Size KmediumHash TableStringBit ManipulationRolling Hash+2frequency 13.2
- Construct the Minimum Bitwise Array IImediumArrayBit Manipulationfrequency 13.2
- Contains Duplicate IIIhardArraySliding WindowSortingBucket Sort+1frequency 13.2
- Convert Binary Number in a Linked List to IntegereasyLinked ListMathfrequency 13.2
- Convert Integer to the Sum of Two No-Zero IntegerseasyMathfrequency 13.2
- Convert the TemperatureeasyMathfrequency 13.2
- Count Complete Subarrays in an ArraymediumArrayHash TableSliding Windowfrequency 13.2
- Count Hills and Valleys in an ArrayeasyArrayfrequency 13.2
- Count Number of Maximum Bitwise-OR SubsetsmediumArrayBacktrackingBit ManipulationEnumerationfrequency 13.2
- Count Palindromic SubsequenceshardStringDynamic Programmingfrequency 13.2
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.