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
- Find the Difference of Two ArrayseasyArrayHash Table5 companies
- Last Person to Fit in the BusmediumDatabase5 companies
- New 21 GamemediumMathDynamic ProgrammingSliding WindowProbability and Statistics5 companies
- Number of Good PairseasyArrayHash TableMathCounting5 companies
- Stone GamemediumArrayMathDynamic ProgrammingMinimax+25 companies
- Unique Length-3 Palindromic SubsequencesmediumHash TableStringBit ManipulationPrefix Sum5 companies
- Design Task ManagermediumHash TableDesignHeap (Priority Queue)Ordered Set5 companies
- Minimum Time Visiting All PointseasyArrayMathGeometry5 companies
- User Activity for the Past 30 Days IeasyDatabase5 companies
- Find Bottom Left Tree ValuemediumTreeDepth-First SearchBreadth-First SearchBinary Tree5 companies
- Minimum Fuel Cost to Report to the CapitalmediumTreeDepth-First SearchBreadth-First SearchGraph Theory5 companies
- Count Negative Numbers in a Sorted MatrixeasyArrayBinary SearchMatrix5 companies
- Divide an Array Into Subarrays With Minimum Cost IeasyArraySortingEnumeration5 companies
- Reverse Words in a String IIIeasyTwo PointersString5 companies
- Split Linked List in PartsmediumLinked List5 companies
- Delete Nodes From Linked List Present in ArraymediumArrayHash TableLinked List5 companies
- Intersection of Two Arrays IIeasyArrayHash TableTwo PointersBinary Search+15 companies
- Count Numbers with Unique DigitsmediumMathDynamic ProgrammingBacktracking5 companies
- Integer BreakmediumMathDynamic Programming5 companies
- Minimum Time DifferencemediumArrayMathStringSorting5 companies
- Unique Binary Search Trees IImediumDynamic ProgrammingBacktrackingTreeBinary Search Tree+15 companies
- Zero Array Transformation IIImediumArrayTwo PointersGreedySorting+25 companies
- Balance a Binary Search TreemediumDivide and ConquerGreedyTreeDepth-First Search+25 companies
- Baseball GameeasyArrayStackSimulation5 companies
- Maximum Erasure ValuemediumArrayHash TableSliding Window5 companies
- Palindrome Partitioning IIhardStringDynamic Programming5 companies
- Course Schedule IIIhardArrayGreedySortingHeap (Priority Queue)5 companies
- Max Chunks To Make Sorted IIhardArrayStackGreedySorting+15 companies
- Bitwise ORs of SubarraysmediumArrayDynamic ProgrammingBit Manipulation5 companies
- Finding 3-Digit Even NumberseasyArrayHash TableRecursionSorting+15 companies
- Game Play Analysis IVmediumDatabase5 companies
- Largest Odd Number in StringeasyMathStringGreedy5 companies
- Longest Subarray of 1's After Deleting One ElementmediumArrayDynamic ProgrammingSliding Window5 companies
- Max Dot Product of Two SubsequenceshardArrayDynamic ProgrammingLongest Common Subsequence5 companies
- Minimum Number of Removals to Make Mountain ArrayhardArrayBinary SearchDynamic ProgrammingGreedy5 companies
- Primary Department for Each EmployeeeasyDatabase5 companies
- The Number of Employees Which Report to Each EmployeeeasyDatabase5 companies
- To Be Or Not To Beeasy5 companies
- Binary Tree Preorder TraversaleasyStackTreeDepth-First SearchBinary Tree5 companies
- Longest Harmonious SubsequenceeasyArrayHash TableSliding WindowSorting+15 companies
- Maximum Score From Removing SubstringsmediumStringStackGreedy5 companies
- Number of Subsequences That Satisfy the Given Sum ConditionmediumArrayTwo PointersBinary SearchSorting5 companies
- Smallest Integer Divisible by KmediumHash TableMathPigeonhole Principle5 companies
- Count Hills and Valleys in an ArrayeasyArray5 companies
- Project Employees IeasyDatabase5 companies
- Find Common CharacterseasyArrayHash TableString5 companies
- Minimum Number of Operations to Make Elements in Array DistincteasyArrayHash Table5 companies
- Sort Array By Parity IIeasyArrayTwo PointersSorting5 companies
- Divide Array Into Arrays With Max DifferencemediumArrayGreedySorting5 companies
- Ones and ZeroesmediumArrayStringDynamic ProgrammingKnapsack Problem+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.