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
- K-th Smallest in Lexicographical OrderhardTrie6 companies
- Minimum Number of Days to Make m BouquetsmediumArrayBinary Search6 companies
- Count Number of Maximum Bitwise-OR SubsetsmediumArrayBacktrackingBit ManipulationEnumeration6 companies
- Maximum Units on a TruckeasyArrayGreedySorting6 companies
- Number of Ways to Paint N × 3 GridhardDynamic ProgrammingGraph Coloring6 companies
- Sort an ArraymediumArrayDivide and ConquerSortingHeap (Priority Queue)+46 companies
- Most Stones Removed with Same Row or ColumnmediumHash TableDepth-First SearchUnion-FindGraph Theory+16 companies
- Number of Ways to Form a Target String Given a DictionaryhardArrayStringDynamic Programming6 companies
- Search in Rotated Sorted Array IImediumArrayBinary Search6 companies
- Number of Sub-arrays of Size K and Average Greater than or Equal to ThresholdmediumArraySliding Window6 companies
- Sum of Square NumbersmediumMathTwo PointersBinary Search6 companies
- Find All Duplicates in an ArraymediumArrayHash TableSorting6 companies
- Min Cost to Connect All PointsmediumArrayUnion-FindGraph TheoryMinimum Spanning Tree+36 companies
- Shortest Subarray with Sum at Least KhardArrayBinary SearchQueueSliding Window+36 companies
- Successful Pairs of Spells and PotionsmediumArrayTwo PointersBinary SearchSorting6 companies
- Invert Binary TreeeasyTreeDepth-First SearchBreadth-First SearchBinary Tree6 companies
- Minimum Cost to Reach Destination in TimehardArrayDynamic ProgrammingGraph TheoryDijkstra's Algorithm6 companies
- Boats to Save PeoplemediumArrayTwo PointersGreedySorting+16 companies
- Power of ThreeeasyMathRecursion6 companies
- Count Complete Tree NodesmediumBinary SearchBit ManipulationTreeBinary Tree6 companies
- Dungeon GamehardArrayDynamic ProgrammingMatrix6 companies
- Find the Safest Path in a GridmediumArrayBinary SearchBreadth-First SearchUnion-Find+26 companies
- Number of Matching SubsequencesmediumArrayHash TableStringBinary Search+36 companies
- Minimum Difficulty of a Job SchedulehardArrayDynamic Programming6 companies
- Binary Subarrays With SummediumArrayHash TableSliding WindowPrefix Sum6 companies
- Partition LabelsmediumHash TableTwo PointersStringGreedy6 companies
- Remove Linked List ElementseasyLinked ListRecursion6 companies
- Check if the Sentence Is PangrameasyHash TableString6 companies
- Number of Digit OnehardMathDynamic ProgrammingRecursion6 companies
- Nth Highest SalarymediumDatabase6 companies
- Assign CookieseasyArrayTwo PointersGreedySorting+16 companies
- Shortest PalindromehardStringRolling HashString MatchingHash Function+36 companies
- Smallest Range Covering Elements from K ListshardArrayHash TableGreedySliding Window+26 companies
- Maximum Width RampmediumArrayTwo PointersStackMonotonic Stack6 companies
- Construct Binary Tree from Inorder and Postorder TraversalmediumArrayHash TableDivide and ConquerTree+16 companies
- CombinationsmediumBacktracking6 companies
- Construct Binary Search Tree from Preorder TraversalmediumArrayStackTreeBinary Search Tree+26 companies
- Minimum Difference in Sums After Removal of ElementshardArrayDynamic ProgrammingHeap (Priority Queue)6 companies
- Count Square Submatrices with All OnesmediumArrayDynamic ProgrammingMatrix6 companies
- Number of Ways to Split ArraymediumArrayPrefix Sum6 companies
- Maximum Population YeareasyArrayCountingPrefix Sum6 companies
- Two Sum IV - Input is a BSTeasyHash TableTwo PointersTreeDepth-First Search+36 companies
- Path Sum IImediumBacktrackingTreeDepth-First SearchBinary Tree6 companies
- Domino and Tromino TilingmediumDynamic Programming6 companies
- Department Top Three SalarieshardDatabase6 companies
- Letter Case PermutationmediumStringBacktrackingBit Manipulation6 companies
- Maximum Size Subarray Sum Equals kmediumArrayHash TablePrefix Sum6 companies
- Minimum Number of Arrows to Burst BalloonsmediumArrayGreedySorting6 companies
- Champagne TowermediumDynamic Programming6 companies
- Longest Duplicate SubstringhardStringBinary SearchSliding WindowRolling Hash+66 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.