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
348 questions at TikTok · all time
- House Robber IIImediumDynamic ProgrammingTreeDepth-First SearchBinary Tree+1frequency 33.0
- Insert Delete GetRandom O(1) - Duplicates allowedhardArrayHash TableMathDesign+1frequency 33.0
- Intersection of Two Linked ListseasyHash TableLinked ListTwo Pointersfrequency 33.0
- Is Graph Bipartite?mediumDepth-First SearchBreadth-First SearchUnion-FindGraph Theory+2frequency 33.0
- LFU CachehardHash TableLinked ListDesignDoubly-Linked Listfrequency 33.0
- Largest NumbermediumArrayStringGreedySortingfrequency 33.0
- Letter Case PermutationmediumStringBacktrackingBit Manipulationfrequency 33.0
- Longest Duplicate SubstringhardStringBinary SearchSliding WindowRolling Hash+6frequency 33.0
- Max StackhardLinked ListStackDesignDoubly-Linked List+1frequency 33.0
- Maximum Points You Can Obtain from CardsmediumArraySliding WindowPrefix Sumfrequency 33.0
- Maximum Product SubarraymediumArrayDynamic Programmingfrequency 33.0
- Maximum Width RampmediumArrayTwo PointersStackMonotonic Stackfrequency 33.0
- Maximum Width of Binary TreemediumTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 33.0
- Median of Two Sorted ArrayshardArrayBinary SearchDivide and Conquerfrequency 33.0
- Merge In Between Linked ListsmediumLinked Listfrequency 33.0
- Merge Two Sorted ListseasyLinked ListRecursionfrequency 33.0
- Minimize Malware SpreadhardArrayHash TableDepth-First SearchBreadth-First Search+2frequency 33.0
- Minimum Difficulty of a Job SchedulehardArrayDynamic Programmingfrequency 33.0
- Minimum Increment to Make Array UniquemediumArrayGreedySortingCountingfrequency 33.0
- Minimum Moves to Spread Stones Over GridmediumArrayDynamic ProgrammingBacktrackingBit Manipulation+2frequency 33.0
- Minimum Number of Arrows to Burst BalloonsmediumArrayGreedySortingfrequency 33.0
- My Calendar ImediumArrayBinary SearchDesignSegment Tree+1frequency 33.0
- Non-overlapping IntervalsmediumArrayDynamic ProgrammingGreedySortingfrequency 33.0
- Number of AtomshardHash TableStringStackSortingfrequency 33.0
- Number of Connected Components in an Undirected GraphmediumDepth-First SearchBreadth-First SearchUnion-FindGraph Theoryfrequency 33.0
- Pairs of Songs With Total Durations Divisible by 60mediumArrayHash TableCountingfrequency 33.0
- Partition Array for Maximum SummediumArrayDynamic Programmingfrequency 33.0
- Path Sum IImediumBacktrackingTreeDepth-First SearchBinary Treefrequency 33.0
- Permutation in StringmediumHash TableTwo PointersStringSliding Windowfrequency 33.0
- Product of the Last K NumbersmediumArrayMathDesignData Stream+1frequency 33.0
- Remove Duplicates from Sorted Array IImediumArrayTwo Pointersfrequency 33.0
- Replace WordsmediumArrayHash TableStringTriefrequency 33.0
- Reverse Linked List IImediumLinked Listfrequency 33.0
- Reverse Words in a StringmediumTwo PointersStringfrequency 33.0
- Roman to IntegereasyHash TableMathStringfrequency 33.0
- Rotate ImagemediumArrayMathMatrixfrequency 33.0
- Score of ParenthesesmediumStringStackBracket Sequencesfrequency 33.0
- Search Suggestions SystemmediumArrayStringBinary SearchTrie+2frequency 33.0
- Serialize and Deserialize N-ary TreehardStringTreeDepth-First SearchBreadth-First Searchfrequency 33.0
- Shortest Distance from All BuildingshardArrayBreadth-First SearchMatrixfrequency 33.0
- Sort ListmediumLinked ListTwo PointersDivide and ConquerSorting+1frequency 33.0
- Step-By-Step Directions From a Binary Tree Node to AnothermediumStringTreeDepth-First SearchBinary Tree+2frequency 33.0
- String CompressionmediumTwo PointersStringfrequency 33.0
- Sum of Subarray MinimumsmediumArrayDynamic ProgrammingStackMonotonic Stackfrequency 33.0
- Task SchedulermediumArrayHash TableGreedySorting+2frequency 33.0
- Time Based Key-Value StoremediumHash TableStringBinary SearchDesignfrequency 33.0
- Valid PalindromeeasyTwo PointersStringfrequency 33.0
- Valid Palindrome IIeasyTwo PointersStringGreedyfrequency 33.0
- Walls and GatesmediumArrayBreadth-First SearchMatrixfrequency 33.0
- 24 GamehardArrayMathBacktrackingfrequency 24.6
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.