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
1,399 questions at Meta · all time
- Repeated String MatchmediumStringString MatchingZ AlgorithmKnuth–Morris–Pratt Algorithm+1frequency 14.4
- Root Equals Sum of ChildreneasyTreeBinary Treefrequency 14.4
- Shortest Common SupersequencehardStringDynamic ProgrammingLongest Common Subsequencefrequency 14.4
- Sign of the Product of an ArrayeasyArrayMathfrequency 14.4
- Smallest Number in Infinite SetmediumHash TableDesignHeap (Priority Queue)Ordered Setfrequency 14.4
- Sort the PeopleeasyArrayHash TableStringSortingfrequency 14.4
- Split Linked List in PartsmediumLinked Listfrequency 14.4
- Successful Pairs of Spells and PotionsmediumArrayTwo PointersBinary SearchSortingfrequency 14.4
- Sum of k-Mirror NumbershardMathEnumerationfrequency 14.4
- The k-th Lexicographical String of All Happy Strings of Length nmediumStringBacktrackingfrequency 14.4
- Three Consecutive OddseasyArrayfrequency 14.4
- To Lower CaseeasyStringfrequency 14.4
- Valid Triangle NumbermediumArrayTwo PointersBinary SearchGreedy+1frequency 14.4
- Word SubsetsmediumArrayHash TableStringfrequency 14.4
- 24 GamehardArrayMathBacktrackingfrequency 11.4
- 4Sum IImediumArrayHash Tablefrequency 11.4
- Add Two Promiseseasyfrequency 11.4
- All Ancestors of a Node in a Directed Acyclic GraphmediumDepth-First SearchBreadth-First SearchGraph TheoryTopological Sort+1frequency 11.4
- Array PartitioneasyArrayGreedySortingCounting Sortfrequency 11.4
- Best Sightseeing PairmediumArrayDynamic Programmingfrequency 11.4
- Binary Tree Level Order Traversal IImediumTreeBreadth-First SearchBinary Treefrequency 11.4
- Binary Tree Longest Consecutive SequencemediumTreeDepth-First SearchBinary TreeDP on Treesfrequency 11.4
- Binary WatcheasyBacktrackingBit Manipulationfrequency 11.4
- Car FleetmediumArrayStackSortingMonotonic Stackfrequency 11.4
- Check If Array Pairs Are Divisible by kmediumArrayHash TableCountingfrequency 11.4
- Check if an Original String Exists Given Two Encoded StringshardStringDynamic Programmingfrequency 11.4
- Clear DigitseasyStringStackSimulationfrequency 11.4
- Construct String from Binary TreemediumStringTreeDepth-First SearchBinary Treefrequency 11.4
- Contains Duplicate IIIhardArraySliding WindowSortingBucket Sort+1frequency 11.4
- Count Elements With Maximum FrequencyeasyArrayHash TableCountingfrequency 11.4
- Count Partitions With Max-Min Difference at Most KmediumArrayDynamic ProgrammingQueueSliding Window+2frequency 11.4
- Count Special TripletsmediumArrayHash TableCountingfrequency 11.4
- Count Subarrays With Score Less Than KhardArrayBinary SearchSliding WindowPrefix Sumfrequency 11.4
- Count Unguarded Cells in the GridmediumArrayMatrixSimulationfrequency 11.4
- Count Ways To Build Good StringsmediumDynamic Programmingfrequency 11.4
- Counting Words With a Given PrefixeasyArrayStringString Matchingfrequency 11.4
- Cousins in Binary TreeeasyTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 11.4
- Crawler Log FoldereasyArrayStringStackfrequency 11.4
- Delete Columns to Make SortedeasyArrayStringLongest Increasing Subsequencefrequency 11.4
- Delete Nodes From Linked List Present in ArraymediumArrayHash TableLinked Listfrequency 11.4
- Delete and EarnmediumArrayHash TableDynamic Programmingfrequency 11.4
- Department Top Three SalarieshardDatabasefrequency 11.4
- Design HashSeteasyArrayHash TableLinked ListDesign+1frequency 11.4
- Design Hit CountermediumArrayBinary SearchDesignQueue+1frequency 11.4
- Design Parking SystemeasyDesignSimulationCountingfrequency 11.4
- Determine Whether Matrix Can Be Obtained By RotationeasyArrayMatrixfrequency 11.4
- Dota2 SenatemediumStringGreedyQueuefrequency 11.4
- Equal Row and Column PairsmediumArrayHash TableMatrixSimulationfrequency 11.4
- Find Closest Number to ZeroeasyArrayfrequency 11.4
- Find Largest Value in Each Tree RowmediumTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 11.4
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.