Problems
Callback's own problems and the LeetCode questions companies have been asking, in one place — pick a category, then filter by company, frequency, status, difficulty, topic, and language.
Asked on LeetCode
3,115 questions · all time
- Design A LeaderboardmediumHash TableDesignSorting7 companies
- Insert into a Binary Search TreemediumTreeBinary Search TreeBinary Tree7 companies
- Valid Triangle NumbermediumArrayTwo PointersBinary SearchGreedy+17 companies
- TrianglemediumArrayDynamic Programming7 companies
- Balanced Binary TreeeasyTreeDepth-First SearchBinary Tree7 companies
- Nearest Exit from Entrance in MazemediumArrayBreadth-First SearchMatrix7 companies
- Substring with Concatenation of All WordshardHash TableStringSliding Window7 companies
- Russian Doll EnvelopeshardArrayBinary SearchDynamic ProgrammingSorting+17 companies
- Unique Paths IIIhardArrayBacktrackingBit ManipulationMatrix+17 companies
- Minimum Absolute DifferenceeasyArraySorting7 companies
- Find K Pairs with Smallest SumsmediumArrayHeap (Priority Queue)7 companies
- K-th Symbol in GrammarmediumMathBit ManipulationRecursion7 companies
- 132 PatternmediumArrayBinary SearchStackMonotonic Stack+17 companies
- Sum of Subarray MinimumsmediumArrayDynamic ProgrammingStackMonotonic Stack7 companies
- Encode and Decode TinyURLmediumHash TableStringDesignHash Function7 companies
- Binary Tree Inorder TraversaleasyStackTreeDepth-First SearchBinary Tree7 companies
- Verifying an Alien DictionaryeasyArrayHash TableString7 companies
- Sort ListmediumLinked ListTwo PointersDivide and ConquerSorting+17 companies
- Populating Next Right Pointers in Each Node IImediumLinked ListTreeDepth-First SearchBreadth-First Search+17 companies
- Maximum Average Subarray IeasyArraySliding Window7 companies
- Most Stones Removed with Same Row or ColumnmediumHash TableDepth-First SearchUnion-FindGraph Theory+17 companies
- Find the Smallest Divisor Given a ThresholdmediumArrayBinary Search7 companies
- Shortest Subarray to be Removed to Make Array SortedmediumArrayTwo PointersBinary SearchStack+17 companies
- Sum of Subarray RangesmediumArrayStackMonotonic Stack7 companies
- Find Eventual Safe StatesmediumDepth-First SearchBreadth-First SearchGraph TheoryTopological Sort+27 companies
- Perfect SquaresmediumMathDynamic ProgrammingBreadth-First SearchKnapsack Problem+17 companies
- Count the Number of Good SubarraysmediumArrayHash TableSliding Window7 companies
- Find Largest Value in Each Tree RowmediumTreeDepth-First SearchBreadth-First SearchBinary Tree7 companies
- Minimum Falling Path SummediumArrayDynamic ProgrammingMatrix7 companies
- Invert Binary TreeeasyTreeDepth-First SearchBreadth-First SearchBinary Tree7 companies
- Boats to Save PeoplemediumArrayTwo PointersGreedySorting+17 companies
- Maximum Points You Can Obtain from CardsmediumArraySliding WindowPrefix Sum7 companies
- Recover Binary Search TreemediumTreeDepth-First SearchBinary Search TreeBinary Tree7 companies
- Serialize and Deserialize N-ary TreehardStringTreeDepth-First SearchBreadth-First Search7 companies
- 2 Keys KeyboardmediumMathDynamic Programming7 companies
- Tree DiametermediumTreeDepth-First SearchBreadth-First SearchGraph Theory+27 companies
- Predict the WinnermediumArrayMathDynamic ProgrammingRecursion+37 companies
- Third Maximum NumbereasyArraySorting7 companies
- Nth DigitmediumMathBinary Search7 companies
- Smallest String With SwapsmediumArrayHash TableStringDepth-First Search+37 companies
- Find Duplicate SubtreesmediumHash TableTreeDepth-First SearchBinary Tree7 companies
- Convert Sorted List to Binary Search TreemediumLinked ListDivide and ConquerTreeBinary Search Tree+17 companies
- Cache With Time Limitmedium6 companies
- Jump Game VImediumArrayDynamic ProgrammingQueueHeap (Priority Queue)+16 companies
- Max StackhardLinked ListStackDesignDoubly-Linked List+16 companies
- Minimum Genetic MutationmediumHash TableStringBreadth-First SearchBidirectional Search6 companies
- Minimum Penalty for a ShopmediumStringPrefix Sum6 companies
- Reaching PointshardMathEuclidean AlgorithmGreatest Common Divisor6 companies
- Replace Employee ID With The Unique IdentifiereasyDatabase6 companies
- Restaurant GrowthmediumDatabase6 companies
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.