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
80 questions at Snap · all time
- LRU CachemediumHash TableLinked ListDesignDoubly-Linked Listfrequency 100.0
- Meeting Rooms IImediumArrayTwo PointersGreedySorting+2frequency 98.6
- Number of IslandsmediumArrayDepth-First SearchBreadth-First SearchUnion-Find+1frequency 98.6
- Word LadderhardHash TableStringBreadth-First SearchBidirectional Searchfrequency 93.7
- Bus RouteshardArrayHash TableBreadth-First Searchfrequency 91.8
- Minimum Window SubstringhardHash TableStringSliding Windowfrequency 91.8
- Number of Distinct IslandsmediumArrayHash TableDepth-First SearchBreadth-First Search+4frequency 91.8
- Design Log Storage SystemmediumHash TableStringDesignOrdered Setfrequency 89.8
- Making A Large IslandhardArrayDepth-First SearchBreadth-First SearchUnion-Find+1frequency 89.8
- Basic Calculator IImediumMathStringStackfrequency 87.6
- Bricks Falling When HithardArrayUnion-FindMatrixfrequency 85.2
- Word Break IIhardArrayHash TableStringDynamic Programming+3frequency 85.2
- Combination SummediumArrayBacktrackingfrequency 82.5
- Course Schedule IImediumDepth-First SearchBreadth-First SearchGraph TheoryTopological Sortfrequency 82.5
- Reverse Words in a StringmediumTwo PointersStringfrequency 82.5
- Alien DictionaryhardArrayStringDepth-First SearchBreadth-First Search+3frequency 79.6
- Binary Tree Vertical Order TraversalmediumHash TableTreeDepth-First SearchBreadth-First Search+2frequency 79.6
- Burst BalloonshardArrayDynamic Programmingfrequency 79.6
- Closest Binary Search Tree ValueeasyBinary SearchTreeDepth-First SearchBinary Search Tree+1frequency 79.6
- Combination Sum IImediumArrayBacktrackingfrequency 79.6
- Combination Sum IVmediumArrayDynamic Programmingfrequency 79.6
- Frog JumphardArrayDynamic Programmingfrequency 79.6
- Game of LifemediumArrayMatrixSimulationfrequency 79.6
- Largest Merge Of Two StringsmediumTwo PointersStringGreedyfrequency 79.6
- Least Operators to Express NumberhardMathDynamic ProgrammingMemoizationfrequency 79.6
- Min StackmediumStackDesignfrequency 79.6
- One Edit DistancemediumTwo PointersStringfrequency 79.6
- Remove K DigitsmediumStringStackGreedyMonotonic Stackfrequency 79.6
- Reverse Linked ListeasyLinked ListRecursionfrequency 79.6
- String CompressionmediumTwo PointersStringfrequency 79.6
- Sudoku SolverhardArrayHash TableBacktrackingMatrix+2frequency 79.6
- Ternary Expression ParsermediumStringStackRecursionfrequency 79.6
- Top K Frequent ElementsmediumArrayHash TableDivide and ConquerSorting+4frequency 79.6
- Unique Binary Search TreesmediumMathDynamic ProgrammingTreeBinary Search Tree+1frequency 79.6
- Valid SudokumediumArrayHash TableMatrixfrequency 79.6
- Wildcard MatchinghardStringDynamic ProgrammingGreedyRecursionfrequency 79.6
- Word AbbreviationhardArrayStringGreedyTrie+1frequency 79.6
- Best Meeting PointhardArrayMathSortingMatrixfrequency 67.7
- Best Time to Buy and Sell Stock IIIhardArrayDynamic Programmingfrequency 67.7
- Decode WaysmediumStringDynamic Programmingfrequency 67.7
- Escape the Spreading FirehardArrayBinary SearchBreadth-First SearchMatrixfrequency 67.7
- Basic Calculator IIIhardMathStringStackRecursionfrequency 62.1
- Count Unreachable Pairs of Nodes in an Undirected GraphmediumDepth-First SearchBreadth-First SearchUnion-FindGraph Theoryfrequency 62.1
- Evaluate DivisionmediumArrayStringDepth-First SearchBreadth-First Search+5frequency 62.1
- Merge IntervalsmediumArraySortingQuicksortfrequency 62.1
- Word SearchmediumArrayStringBacktrackingDepth-First Search+1frequency 62.1
- Basic CalculatorhardMathStringStackRecursionfrequency 55.0
- Course SchedulemediumDepth-First SearchBreadth-First SearchGraph TheoryTopological Sort+1frequency 55.0
- LFU CachehardHash TableLinked ListDesignDoubly-Linked Listfrequency 55.0
- Letter Combinations of a Phone NumbermediumHash TableStringBacktrackingfrequency 55.0
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.