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
3,110 questions · all time
- Trionic Array IeasyArray3 companies
- Delete Operation for Two StringsmediumStringDynamic ProgrammingLongest Common Subsequence3 companies
- Largest Number At Least Twice of OtherseasyArraySorting3 companies
- Maximum Number of K-Divisible ComponentshardTreeDepth-First Search3 companies
- Relative RankseasyArraySortingHeap (Priority Queue)3 companies
- Concatenation of Consecutive Binary NumbersmediumMathBit ManipulationSimulation3 companies
- Maximize Happiness of Selected ChildrenmediumArrayGreedySorting3 companies
- Maximum Score Words Formed by LettershardArrayHash TableStringDynamic Programming+43 companies
- Number of Smooth Descent Periods of a StockmediumArrayMathTwo PointersDynamic Programming+13 companies
- Serialize and Deserialize BSTmediumStringTreeDepth-First SearchBreadth-First Search+33 companies
- Uncrossed LinesmediumArrayDynamic ProgrammingLongest Common Subsequence3 companies
- Validate Binary Tree NodesmediumTreeDepth-First SearchBreadth-First SearchUnion-Find+23 companies
- Classes With at Least 5 StudentseasyDatabase3 companies
- String Compression IIhardStringDynamic Programming3 companies
- 3Sum SmallermediumArrayTwo PointersBinary SearchSorting3 companies
- Check if All Characters Have Equal Number of OccurrenceseasyHash TableStringCounting3 companies
- Find Maximum Non-decreasing Array LengthhardArrayBinary SearchDynamic ProgrammingStack+43 companies
- Furthest Point From OrigineasyStringCounting3 companies
- Maximum Performance of a TeamhardArrayGreedySortingHeap (Priority Queue)3 companies
- Rearrange String k Distance AparthardHash TableStringGreedySorting+23 companies
- Wiggle SortmediumArrayGreedySorting3 companies
- Find Target Indices After Sorting ArrayeasyArrayBinary SearchSorting3 companies
- Matrix Block SummediumArrayMatrixPrefix Sum3 companies
- Maximum Frequency of an Element After Performing Operations IIhardArrayBinary SearchSliding WindowSorting+13 companies
- Unique Email AddresseseasyArrayHash TableString3 companies
- Length of the Longest Valid SubstringhardArrayHash TableStringSliding Window3 companies
- Longest Repeating SubstringmediumStringBinary SearchDynamic ProgrammingRolling Hash+43 companies
- Monotone Increasing DigitsmediumMathGreedy3 companies
- Read N Characters Given Read4easyArraySimulationInteractive3 companies
- Separate the Digits in an ArrayeasyArraySimulation3 companies
- Count of Range SumhardArrayBinary SearchDivide and ConquerBinary Indexed Tree+43 companies
- Delete Columns to Make SortedeasyArrayStringLongest Increasing Subsequence3 companies
- Flip Equivalent Binary TreesmediumTreeDepth-First SearchBinary Tree3 companies
- Range Sum Query 2D - MutablemediumArrayDesignBinary Indexed TreeSegment Tree+23 companies
- Tiling a Rectangle with the Fewest SquareshardBacktracking3 companies
- Separate Black and White BallsmediumTwo PointersStringGreedy3 companies
- Shifting LettersmediumArrayStringPrefix Sum3 companies
- Checking Existence of Edge Length Limited PathshardArrayTwo PointersUnion-FindGraph Theory+13 companies
- Delete Columns to Make Sorted IImediumArrayStringGreedy3 companies
- Frog Jump IImediumArrayBinary SearchGreedy3 companies
- Max Sum of Rectangle No Larger Than KhardArrayBinary SearchMatrixPrefix Sum+13 companies
- Number of Good PathshardArrayHash TableTreeUnion-Find+23 companies
- Student Attendance Record IeasyString3 companies
- Delete Leaves With a Given ValuemediumTreeDepth-First SearchBinary Tree3 companies
- Minimum Distance to the Target ElementeasyArray3 companies
- Shift 2D GrideasyArrayMatrixSimulation3 companies
- Check Knight Tour ConfigurationmediumArrayDepth-First SearchBreadth-First SearchMatrix+13 companies
- Longest Subsequence Repeated k TimeshardHash TableTwo PointersStringBacktracking+23 companies
- Filter Elements from Arrayeasy3 companies
- Find Root of N-Ary TreemediumHash TableBit ManipulationTreeDepth-First Search3 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.