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
- Plus OneeasyArrayMathfrequency 50.4
- Balanced Binary TreeeasyTreeDepth-First SearchBinary Treefrequency 50.0
- Basic Calculator IImediumMathStringStackfrequency 50.0
- Evaluate DivisionmediumArrayStringDepth-First SearchBreadth-First Search+5frequency 50.0
- Longest Valid ParentheseshardStringDynamic ProgrammingStackBracket Sequencesfrequency 50.0
- Rotate ListmediumLinked ListTwo Pointersfrequency 50.0
- Check if Array Is Sorted and RotatedeasyArrayfrequency 49.7
- Decode StringmediumStringStackRecursionfrequency 49.7
- Contains Duplicate IIeasyArrayHash TableSliding Windowfrequency 49.3
- Maximum Frequency After Subarray OperationmediumArrayHash TableDynamic ProgrammingGreedy+2frequency 48.9
- Minimum Size Subarray SummediumArrayBinary SearchSliding WindowPrefix Sumfrequency 48.9
- Remove Duplicates from Sorted Array IImediumArrayTwo Pointersfrequency 48.9
- Concatenation of ArrayeasyArraySimulationfrequency 48.5
- Integer to English WordshardMathStringRecursionfrequency 48.5
- Sudoku SolverhardArrayHash TableBacktrackingMatrix+2frequency 48.5
- Permutation in StringmediumHash TableTwo PointersStringSliding Windowfrequency 48.1
- Rotate StringeasyStringString Matchingfrequency 48.1
- Same TreeeasyTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 48.1
- Plates Between CandlesmediumArrayStringBinary SearchPrefix Sumfrequency 47.7
- Second Highest SalarymediumDatabasefrequency 47.7
- Time Based Key-Value StoremediumHash TableStringBinary SearchDesignfrequency 47.7
- Find Minimum in Rotated Sorted ArraymediumArrayBinary Searchfrequency 47.3
- Isomorphic StringseasyHash TableStringfrequency 47.3
- K Closest Points to OriginmediumArrayMathDivide and ConquerGeometry+4frequency 47.3
- Maximum Coins From K Consecutive BagsmediumArrayBinary SearchGreedySliding Window+2frequency 47.3
- Symmetric TreeeasyTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 47.3
- Vertical Order Traversal of a Binary TreehardHash TableTreeDepth-First SearchBreadth-First Search+2frequency 47.3
- Count PrimesmediumArrayMathEnumerationNumber Theory+3frequency 46.9
- Evaluate Reverse Polish NotationmediumArrayMathStackfrequency 46.9
- Maximum Depth of Binary TreeeasyTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 46.9
- Surrounded RegionsmediumArrayDepth-First SearchBreadth-First SearchUnion-Find+1frequency 46.9
- Article Views IeasyDatabasefrequency 46.5
- Make Array Zero by Subtracting Equal AmountseasyArrayHash TableGreedySorting+2frequency 46.5
- Search Suggestions SystemmediumArrayStringBinary SearchTrie+2frequency 46.5
- Find All Anagrams in a StringmediumHash TableStringSliding Windowfrequency 46.0
- Intersection of Two Linked ListseasyHash TableLinked ListTwo Pointersfrequency 46.0
- Peak Index in a Mountain ArraymediumArrayBinary SearchTernary Searchfrequency 46.0
- Sort ListmediumLinked ListTwo PointersDivide and ConquerSorting+1frequency 46.0
- Subarrays with K Different IntegershardArrayHash TableSliding WindowCountingfrequency 46.0
- Maximum Width of Binary TreemediumTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 45.6
- Pacific Atlantic Water FlowmediumArrayDepth-First SearchBreadth-First SearchMatrixfrequency 45.6
- Random Pick with WeightmediumArrayMathBinary SearchPrefix Sum+1frequency 45.6
- Reverse StringeasyTwo PointersStringfrequency 45.6
- Construct Binary Tree from Preorder and Inorder TraversalmediumArrayHash TableDivide and ConquerTree+1frequency 45.1
- Find K Closest ElementsmediumArrayTwo PointersBinary SearchSliding Window+2frequency 45.1
- Kth Smallest Element in a BSTmediumTreeDepth-First SearchBinary Search TreeBinary Treefrequency 45.1
- Lowest Common Ancestor of a Binary Search TreemediumTreeDepth-First SearchBinary Search TreeBinary Tree+2frequency 45.1
- Maximal RectanglehardArrayDynamic ProgrammingStackMatrix+1frequency 45.1
- Populating Next Right Pointers in Each NodemediumLinked ListTreeDepth-First SearchBreadth-First Search+1frequency 45.1
- Reverse Linked List IImediumLinked Listfrequency 45.1
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.