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
3,110 questions · all time
- Sum Root to Leaf NumbersmediumTreeDepth-First SearchBinary Tree5 companies
- Degree of an ArrayeasyArrayHash Table5 companies
- Range Sum of BSTeasyTreeDepth-First SearchBinary Search TreeBinary Tree5 companies
- Count Subarrays With Score Less Than KhardArrayBinary SearchSliding WindowPrefix Sum5 companies
- Minimum Edge Reversals So Every Node Is ReachablehardDynamic ProgrammingDepth-First SearchBreadth-First SearchGraph Theory5 companies
- Split Message Based on LimithardStringEnumeration5 companies
- Rectangle OverlapeasyMathGeometry5 companies
- Maximum Subsequence ScoremediumArrayGreedySortingHeap (Priority Queue)5 companies
- Custom Sort StringmediumHash TableStringSorting5 companies
- Maximum Palindromes After OperationsmediumArrayHash TableStringGreedy+25 companies
- Design Underground SystemmediumHash TableStringDesign5 companies
- Minimum Add to Make Parentheses ValidmediumStringStackGreedyBracket Sequences5 companies
- Employee ImportancemediumArrayHash TableTreeDepth-First Search+15 companies
- Design Parking SystemeasyDesignSimulationCounting5 companies
- Minimum Cost Walk in Weighted GraphhardArrayBit ManipulationUnion-FindGraph Theory5 companies
- Relative Sort ArrayeasyArrayHash TableSortingCounting Sort+25 companies
- Create Hello World Functioneasy5 companies
- Equal Row and Column PairsmediumArrayHash TableMatrixSimulation5 companies
- Longest Happy StringmediumStringGreedyHeap (Priority Queue)5 companies
- Detect SquaresmediumArrayHash TableDesignCounting+15 companies
- Recyclable and Low Fat ProductseasyDatabase5 companies
- Paint HousemediumArrayDynamic Programming5 companies
- Power Grid MaintenancemediumArrayHash TableDepth-First SearchBreadth-First Search+45 companies
- Check if One String Swap Can Make Strings EqualeasyHash TableStringCounting5 companies
- Inorder Successor in BSTmediumTreeDepth-First SearchBinary Search TreeBinary Tree5 companies
- Minimum Cost to Make at Least One Valid Path in a GridhardArrayBreadth-First SearchGraph TheoryHeap (Priority Queue)+45 companies
- Number of AtomshardHash TableStringStackSorting5 companies
- Length of Longest Subarray With at Most K FrequencymediumArrayHash TableSliding Window5 companies
- Bulls and CowsmediumHash TableStringCounting5 companies
- Kth Smallest Number in Multiplication TablehardMathBinary Search5 companies
- Check if Array Is Sorted and RotatedeasyArray5 companies
- All Paths From Source to TargetmediumBacktrackingDepth-First SearchBreadth-First SearchGraph Theory+15 companies
- Count the Hidden SequencesmediumArrayPrefix Sum5 companies
- Alice and Bob Playing Flower GamemediumMath5 companies
- Concatenation of ArrayeasyArraySimulation5 companies
- Combine Two TableseasyDatabase5 companies
- Range ModulehardDesignSegment TreeOrdered Set5 companies
- Divide Nodes Into the Maximum Number of GroupshardDepth-First SearchBreadth-First SearchUnion-FindGraph Theory5 companies
- Max Consecutive OneseasyArray5 companies
- Shuffle an ArraymediumArrayMathDesignRandomized5 companies
- Number of Adjacent Elements With the Same ColormediumArray5 companies
- Sort Items by Groups Respecting DependencieshardDepth-First SearchBreadth-First SearchGraph TheoryTopological Sort+15 companies
- Count the Number of InversionshardArrayDynamic Programming5 companies
- Exam RoommediumDesignHeap (Priority Queue)Ordered Set5 companies
- Find the Minimum Area to Cover All Ones ImediumArrayMatrix5 companies
- Matrix Similarity After Cyclic ShiftseasyArrayMathMatrixSimulation5 companies
- Kth Smallest Product of Two Sorted ArrayshardArrayBinary Search5 companies
- Maximize Subarrays After Removing One Conflicting PairhardArraySegment TreeEnumerationPrefix Sum5 companies
- Check If a String Contains All Binary Codes of Size KmediumHash TableStringBit ManipulationRolling Hash+25 companies
- Beautiful ArrangementmediumArrayDynamic ProgrammingBacktrackingBit Manipulation+15 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.