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
- Remove Duplicates From an Unsorted Linked ListmediumHash TableLinked List2 companies
- Shuffle StringeasyArrayString2 companies
- Maximum Sum With at Most K ElementsmediumArrayGreedySortingHeap (Priority Queue)+12 companies
- Minimum Operations to Make the Array AlternatingmediumArrayHash TableGreedyCounting2 companies
- Path CrossingeasyHash TableString2 companies
- Longest Arithmetic Subsequence of Given DifferencemediumArrayHash TableDynamic Programming2 companies
- Count Covered BuildingsmediumArrayHash TableSorting2 companies
- Largest 1-Bordered SquaremediumArrayDynamic ProgrammingMatrix2 companies
- Maximize Sum of Weights after Edge RemovalshardDynamic ProgrammingTreeDepth-First SearchSorting2 companies
- Maximum Length of Pair ChainmediumArrayDynamic ProgrammingGreedySorting+12 companies
- Number of Subarrays That Match a Pattern ImediumArrayRolling HashString MatchingHash Function2 companies
- Partition Array Such That Maximum Difference Is KmediumArrayGreedySorting2 companies
- Random Point in Non-overlapping RectanglesmediumArrayMathBinary SearchReservoir Sampling+32 companies
- Strictly Palindromic NumbermediumMathTwo PointersBrainteaser2 companies
- Super Washing MachineshardArrayGreedy2 companies
- Finding the Number of Visible MountainsmediumArrayStackSortingMonotonic Stack2 companies
- Maximum Number of Ways to Partition an ArrayhardArrayHash TableCountingEnumeration+12 companies
- Bitwise OR of Even Numbers in an ArrayeasyArrayBit ManipulationSimulation2 companies
- Check if All A's Appears Before All B'seasyString2 companies
- Count Submatrices With Equal Frequency of X and YmediumArrayMatrixPrefix Sum2 companies
- Find the Median of the Uniqueness ArrayhardArrayHash TableBinary SearchSliding Window2 companies
- Largest BST SubtreemediumDynamic ProgrammingTreeDepth-First SearchBinary Search Tree+22 companies
- Maximum Size of a Set After RemovalsmediumArrayHash TableGreedy2 companies
- Maximum of Absolute Value ExpressionmediumArrayMath2 companies
- Minimum Amount of Time to Collect GarbagemediumArrayStringPrefix Sum2 companies
- Stable Subarrays With Equal Boundary and Interior SummediumArrayHash TablePrefix Sum2 companies
- Minimum Difference Between Largest and Smallest Value in Three MovesmediumArrayGreedySorting2 companies
- Minimum Operations to Reduce X to ZeromediumArrayHash TableBinary SearchSliding Window+12 companies
- Intersection of Three Sorted ArrayseasyArrayHash TableBinary SearchCounting2 companies
- Minimum Path Cost in a Hidden GridmediumArrayDepth-First SearchBreadth-First SearchGraph Theory+42 companies
- Clone Binary Tree With Random PointermediumHash TableTreeDepth-First SearchBreadth-First Search+12 companies
- Count the Number of Special Characters IeasyHash TableString2 companies
- Cousins in Binary Tree IImediumHash TableTreeDepth-First SearchBreadth-First Search+12 companies
- List the Products Ordered in a PeriodeasyDatabase2 companies
- Maximum Total from Optimal Activation OrdermediumArrayTwo PointersGreedySorting+12 companies
- Total Appeal of A StringhardHash TableStringDynamic Programming2 companies
- First Letter to Appear TwiceeasyHash TableStringBit ManipulationCounting2 companies
- Student Attendance Record IIhardDynamic Programming2 companies
- Find the Most Competitive SubsequencemediumArrayStackGreedyMonotonic Stack2 companies
- Longest Increasing Subsequence IIhardArrayDivide and ConquerDynamic ProgrammingBinary Indexed Tree+32 companies
- Maximum Product of Word LengthsmediumArrayStringBit Manipulation2 companies
- Path With Maximum Minimum ValuemediumArrayBinary SearchDepth-First SearchBreadth-First Search+42 companies
- Count Stepping Numbers in RangehardStringDynamic Programming2 companies
- Decode Ways IIhardStringDynamic Programming2 companies
- Find and Replace PatternmediumArrayHash TableString2 companies
- Get Watched Videos by Your FriendsmediumArrayHash TableBreadth-First SearchGraph Theory+12 companies
- H-Index IImediumArrayBinary Search2 companies
- Minimum Deletions for At Most K Distinct CharacterseasyHash TableStringGreedySorting+12 companies
- Minimum Number of Operations to Sort a Binary Tree by LevelmediumTreeBreadth-First SearchBinary Tree2 companies
- Number of Distinct Islands IIhardArrayHash TableDepth-First SearchBreadth-First Search+42 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.