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
2,344 questions at Google · all time
- Ugly NumbereasyMathfrequency 33.1
- Binary Tree PathseasyStringBacktrackingTreeDepth-First Search+1frequency 32.4
- CombinationsmediumBacktrackingfrequency 32.4
- Convert Sorted Array to Binary Search TreeeasyArrayDivide and ConquerTreeBinary Search Tree+1frequency 32.4
- Count Days Without MeetingsmediumArraySortingfrequency 32.4
- Design a Stack With Increment OperationmediumArrayStackDesignfrequency 32.4
- Flatten Binary Tree to Linked ListmediumLinked ListStackTreeDepth-First Search+1frequency 32.4
- Maximum Points You Can Obtain from CardsmediumArraySliding WindowPrefix Sumfrequency 32.4
- Monthly Transactions ImediumDatabasefrequency 32.4
- Non-overlapping IntervalsmediumArrayDynamic ProgrammingGreedySortingfrequency 32.4
- Number of Closed IslandsmediumArrayDepth-First SearchBreadth-First SearchUnion-Find+1frequency 32.4
- Path Existence Queries in a Graph ImediumArrayHash TableBinary SearchUnion-Find+1frequency 32.4
- Replace Employee ID With The Unique IdentifiereasyDatabasefrequency 32.4
- Sort Characters By FrequencymediumHash TableStringSortingHeap (Priority Queue)+2frequency 32.4
- Soup ServingsmediumMathDynamic ProgrammingProbability and Statisticsfrequency 32.4
- The Latest Time to Catch a BusmediumArrayTwo PointersBinary SearchSortingfrequency 32.4
- Type of TriangleeasyArrayMathSortingPolygonsfrequency 32.4
- Car FleetmediumArrayStackSortingMonotonic Stackfrequency 31.8
- Champagne TowermediumDynamic Programmingfrequency 31.8
- Continuous SubarraysmediumArrayQueueSliding WindowHeap (Priority Queue)+2frequency 31.8
- Delete Node in a BSTmediumTreeBinary Search TreeBinary Treefrequency 31.8
- Excel Sheet Column TitleeasyMathStringfrequency 31.8
- Find All Anagrams in a StringmediumHash TableStringSliding Windowfrequency 31.8
- Flood FilleasyArrayDepth-First SearchBreadth-First SearchMatrixfrequency 31.8
- Inverse Coin ChangemediumArrayDynamic Programmingfrequency 31.8
- Linked List Random NodemediumLinked ListMathReservoir SamplingRandomizedfrequency 31.8
- Maximum Good Subarray SummediumArrayHash TablePrefix Sumfrequency 31.8
- Maximum Number of Events That Can Be AttendedmediumArrayGreedySortingHeap (Priority Queue)frequency 31.8
- Minimum Number of Operations to Move All Balls to Each BoxmediumArrayStringPrefix Sumfrequency 31.8
- Minimum Weighted Subgraph With the Required PathshardGraph TheoryHeap (Priority Queue)Shortest Pathfrequency 31.8
- Nth DigitmediumMathBinary Searchfrequency 31.8
- Palindromic SubstringsmediumTwo PointersStringDynamic Programmingfrequency 31.8
- Recover Binary Search TreemediumTreeDepth-First SearchBinary Search TreeBinary Treefrequency 31.8
- Remove Linked List ElementseasyLinked ListRecursionfrequency 31.8
- Sequence ReconstructionmediumArrayGraph TheoryTopological SortDirected Acyclic Graphfrequency 31.8
- Students and ExaminationseasyDatabasefrequency 31.8
- Sum of Distances in TreehardDynamic ProgrammingTreeDepth-First SearchGraph Theory+1frequency 31.8
- Top K Frequent WordsmediumArrayHash TableStringTrie+4frequency 31.8
- Transpose MatrixeasyArrayMatrixSimulationfrequency 31.8
- Unique Paths IImediumArrayDynamic ProgrammingMatrixfrequency 31.8
- Best Time to Buy and Sell Stock IIIhardArrayDynamic Programmingfrequency 31.1
- Detect SquaresmediumArrayHash TableDesignCounting+1frequency 31.1
- Detonate the Maximum BombsmediumArrayMathDepth-First SearchBreadth-First Search+2frequency 31.1
- Flipping an ImageeasyArrayTwo PointersBit ManipulationMatrix+1frequency 31.1
- Fraction to Recurring DecimalmediumHash TableMathStringfrequency 31.1
- Height of Binary Tree After Subtree Removal QuerieshardArrayTreeDepth-First SearchBreadth-First Search+1frequency 31.1
- Longest PalindromeeasyHash TableStringGreedyfrequency 31.1
- Maximum Candies Allocated to K ChildrenmediumArrayBinary Searchfrequency 31.1
- Minimum Cost to Make at Least One Valid Path in a GridhardArrayBreadth-First SearchGraph TheoryHeap (Priority Queue)+4frequency 31.1
- Number of 1 BitseasyDivide and ConquerBit Manipulationfrequency 31.1
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.