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
- Combination Sum IImediumArrayBacktracking11 companies
- Dot Product of Two Sparse VectorsmediumArrayHash TableTwo PointersDesign+111 companies
- Longest Valid ParentheseshardStringDynamic ProgrammingStackBracket Sequences11 companies
- Valid Parenthesis StringmediumStringDynamic ProgrammingStackGreedy+111 companies
- Reverse BitseasyDivide and ConquerBit Manipulation11 companies
- Number of Visible People in a QueuehardArrayStackMonotonic Stack11 companies
- Employee Free TimehardArraySweep LineSortingHeap (Priority Queue)11 companies
- Insert IntervalmediumArray11 companies
- Minimum Path SummediumArrayDynamic ProgrammingMatrix11 companies
- Decode WaysmediumStringDynamic Programming11 companies
- Maximum Depth of Binary TreeeasyTreeDepth-First SearchBreadth-First SearchBinary Tree11 companies
- First Missing PositivehardArrayHash Table11 companies
- Search a 2D MatrixmediumArrayBinary SearchMatrix11 companies
- Reorder ListmediumLinked ListTwo PointersStackRecursion11 companies
- Longest Common SubsequencemediumStringDynamic ProgrammingLongest Common Subsequence11 companies
- Find Minimum in Rotated Sorted ArraymediumArrayBinary Search11 companies
- Minimum Size Subarray SummediumArrayBinary SearchSliding WindowPrefix Sum11 companies
- Capacity To Ship Packages Within D DaysmediumArrayBinary Search10 companies
- Longest String ChainmediumArrayHash TableTwo PointersString+210 companies
- Remove All Adjacent Duplicates in String IImediumStringStack10 companies
- Special Binary StringhardStringDivide and ConquerSorting10 companies
- Design In-Memory File SystemhardHash TableStringDesignTrie+110 companies
- Squares of a Sorted ArrayeasyArrayTwo PointersSorting10 companies
- Partition Equal Subset SummediumArrayDynamic ProgrammingKnapsack Problem0-1 Knapsack10 companies
- Single Element in a Sorted ArraymediumArrayBinary Search10 companies
- Remove K DigitsmediumStringStackGreedyMonotonic Stack10 companies
- Vertical Order Traversal of a Binary TreehardHash TableTreeDepth-First SearchBreadth-First Search+210 companies
- Minimum Number of Taps to Open to Water a GardenhardArrayDynamic ProgrammingGreedy10 companies
- Copy List with Random PointermediumHash TableLinked List10 companies
- Set Matrix ZeroesmediumArrayHash TableMatrix10 companies
- Linked List CycleeasyHash TableLinked ListTwo PointersFloyd's Cycle Finding Algorithm10 companies
- Intersection of Two Linked ListseasyHash TableLinked ListTwo Pointers10 companies
- My Calendar ImediumArrayBinary SearchDesignSegment Tree+110 companies
- Restore IP AddressesmediumStringBacktracking10 companies
- Insert Delete GetRandom O(1) - Duplicates allowedhardArrayHash TableMathDesign+110 companies
- Fizz BuzzeasyMathStringSimulation10 companies
- Contains DuplicateeasyArrayHash TableSorting10 companies
- CandyhardArrayGreedy10 companies
- Best Time to Buy and Sell Stock IIIhardArrayDynamic Programming10 companies
- Split Array Largest SumhardArrayBinary SearchDynamic ProgrammingGreedy+110 companies
- Minimum Knight MovesmediumBreadth-First SearchHeuristic SearchBidirectional SearchA* Search10 companies
- House Robber IIImediumDynamic ProgrammingTreeDepth-First SearchBinary Tree+110 companies
- Maximum Number of Events That Can Be AttendedmediumArrayGreedySortingHeap (Priority Queue)10 companies
- Search a 2D Matrix IImediumArrayBinary SearchDivide and ConquerMatrix10 companies
- Subarrays with K Different IntegershardArrayHash TableSliding WindowCounting10 companies
- 4SummediumArrayTwo PointersSorting10 companies
- Binary Tree Level Order TraversalmediumTreeBreadth-First SearchBinary Tree10 companies
- Count PrimesmediumArrayMathEnumerationNumber Theory+310 companies
- Missing NumbereasyArrayHash TableMathBinary Search+210 companies
- Spiral Matrix IImediumArrayMatrixSimulation10 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.