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
- 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
- Minimum Number of Operations to Move All Balls to Each BoxmediumArrayStringPrefix Sum6 companies
- Sum of Distances in TreehardDynamic ProgrammingTreeDepth-First SearchGraph Theory+16 companies
- Angle Between Hands of a ClockmediumMath6 companies
- Design Linked ListmediumLinked ListDesign6 companies
- IPOhardArrayGreedySortingHeap (Priority Queue)6 companies
- Repeated String MatchmediumStringString MatchingZ AlgorithmKnuth–Morris–Pratt Algorithm+16 companies
- Island PerimetereasyArrayDepth-First SearchBreadth-First SearchMatrix6 companies
- Max Chunks To Make SortedmediumArrayStackGreedySorting+16 companies
- Pascal's Triangle IIeasyArrayDynamic Programming6 companies
- Number of Operations to Make Network ConnectedmediumDepth-First SearchBreadth-First SearchUnion-FindGraph Theory6 companies
- Lexicographically Minimum String After Removing StarsmediumHash TableStringStackGreedy+16 companies
- Find the Longest Substring Containing Vowels in Even CountsmediumHash TableStringBit ManipulationPrefix Sum6 companies
- Delete the Middle Node of a Linked ListmediumLinked ListTwo Pointers6 companies
- Number of EnclavesmediumArrayDepth-First SearchBreadth-First SearchUnion-Find+16 companies
- Painting a Grid With Three Different ColorshardDynamic ProgrammingGraph Coloring6 companies
- Distribute Coins in Binary TreemediumTreeDepth-First SearchBinary TreeDP on Trees6 companies
- Smallest Number in Infinite SetmediumHash TableDesignHeap (Priority Queue)Ordered Set6 companies
- Ugly Number IImediumHash TableMathDynamic ProgrammingHeap (Priority Queue)6 companies
- Find a Peak Element IImediumArrayBinary SearchMatrix6 companies
- Human Traffic of StadiumhardDatabase6 companies
- Valid Mountain ArrayeasyArray6 companies
- Construct Binary Tree from Preorder and Postorder TraversalmediumArrayHash TableDivide and ConquerTree+16 companies
- Longest Happy PrefixhardStringRolling HashString MatchingHash Function+26 companies
- Parsing A Boolean ExpressionhardStringStackRecursion6 companies
- Find the Maximum Length of Valid Subsequence IImediumArrayDynamic Programming6 companies
- Length of Longest Fibonacci SubsequencemediumArrayHash TableDynamic Programming6 companies
- Long Pressed NameeasyTwo PointersString6 companies
- Design a Stack With Increment OperationmediumArrayStackDesign5 companies
- Dota2 SenatemediumStringGreedyQueue5 companies
- Maximum Number of Visible PointshardArrayMathGeometrySliding Window+15 companies
- Most Common WordeasyArrayHash TableStringCounting5 companies
- Walking Robot SimulationmediumArrayHash TableSimulation5 companies
- Alternating Groups IImediumArraySliding Window5 companies
- Brightest Position on StreetmediumArraySortingPrefix SumOrdered Set5 companies
- Number of People Aware of a SecretmediumDynamic ProgrammingQueueSimulation5 companies
- Maximum Subarray Sum with One DeletionmediumArrayDynamic Programming5 companies
- Word Pattern IImediumHash TableStringBacktracking5 companies
- Remove BoxeshardArrayDynamic ProgrammingMemoization5 companies
- Invalid TransactionsmediumArrayHash TableStringSorting5 companies
- Make The String GreateasyStringStack5 companies
- Minimum Window SubsequencehardStringDynamic ProgrammingSliding Window5 companies
- Maximum Repeating SubstringeasyStringDynamic ProgrammingString Matching5 companies
- Nested List Weight SummediumDepth-First SearchBreadth-First Search5 companies
- Analyze User Website Visit PatternmediumArrayHash TableStringSorting5 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.