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
- Walls and GatesmediumArrayBreadth-First SearchMatrixfrequency 42.0
- Zigzag ConversionmediumStringfrequency 42.0
- Asteroid CollisionmediumArrayStackSimulationfrequency 41.4
- Remove Duplicates from Sorted Array IImediumArrayTwo Pointersfrequency 41.4
- Rising TemperatureeasyDatabasefrequency 41.4
- Search a 2D MatrixmediumArrayBinary SearchMatrixfrequency 41.4
- Subsets IImediumArrayBacktrackingBit Manipulationfrequency 41.4
- Article Views IeasyDatabasefrequency 40.7
- Car PoolingmediumArraySortingHeap (Priority Queue)Simulation+1frequency 40.7
- Count and SaymediumStringfrequency 40.7
- Find Minimum in Rotated Sorted ArraymediumArrayBinary Searchfrequency 40.7
- First Missing PositivehardArrayHash Tablefrequency 40.7
- Increasing Triplet SubsequencemediumArrayGreedyLongest Increasing Subsequencefrequency 40.7
- Max Consecutive OneseasyArrayfrequency 40.7
- Maximal RectanglehardArrayDynamic ProgrammingStackMatrix+1frequency 40.7
- Minimum Time to Collect All Apples in a TreemediumHash TableTreeDepth-First SearchBreadth-First Search+1frequency 40.7
- Next Greater Element IeasyArrayHash TableStackMonotonic Stackfrequency 40.7
- Odd Even Linked ListmediumLinked Listfrequency 40.7
- Reverse Nodes in k-GrouphardLinked ListRecursionfrequency 40.7
- Binary Tree Inorder TraversaleasyStackTreeDepth-First SearchBinary Treefrequency 40.0
- Populating Next Right Pointers in Each Node IImediumLinked ListTreeDepth-First SearchBreadth-First Search+1frequency 40.0
- Shortest Path in a Hidden GridmediumArrayDepth-First SearchBreadth-First SearchMatrix+1frequency 40.0
- Sparse Matrix MultiplicationmediumArrayHash TableMatrixLinear Algebrafrequency 40.0
- Swim in Rising WaterhardArrayBinary SearchDepth-First SearchBreadth-First Search+5frequency 40.0
- Integer to RomanmediumHash TableMathStringfrequency 39.2
- Linked List CycleeasyHash TableLinked ListTwo PointersFloyd's Cycle Finding Algorithmfrequency 39.2
- Missing NumbereasyArrayHash TableMathBinary Search+2frequency 39.2
- Rotting OrangesmediumArrayBreadth-First SearchMatrixfrequency 39.2
- Simple Bank SystemmediumArrayHash TableDesignSimulationfrequency 39.2
- Sort Characters By FrequencymediumHash TableStringSortingHeap (Priority Queue)+2frequency 39.2
- Word Ladder IIhardHash TableStringBacktrackingBreadth-First Search+1frequency 39.2
- Binary Tree Zigzag Level Order TraversalmediumTreeBreadth-First SearchBinary Treefrequency 38.5
- Combination Sum IImediumArrayBacktrackingfrequency 38.5
- Concatenation of ArrayeasyArraySimulationfrequency 38.5
- Find the Duplicate NumbermediumArrayTwo PointersBinary SearchBit Manipulation+2frequency 38.5
- Isomorphic StringseasyHash TableStringfrequency 38.5
- Maximum Depth of Binary TreeeasyTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 38.5
- Next Greater Element IImediumArrayStackMonotonic Stackfrequency 38.5
- Search in Rotated Sorted Array IImediumArrayBinary Searchfrequency 38.5
- Smallest Subtree with all the Deepest NodesmediumHash TableTreeDepth-First SearchBreadth-First Search+4frequency 38.5
- Text JustificationhardArrayStringSimulationfrequency 38.5
- CombinationsmediumBacktrackingfrequency 37.7
- Flatten Nested List IteratormediumStackTreeDepth-First SearchDesign+2frequency 37.7
- Insert IntervalmediumArrayfrequency 37.7
- Jump Game IImediumArrayDynamic ProgrammingGreedyfrequency 37.7
- Largest NumbermediumArrayStringGreedySortingfrequency 37.7
- Maximum Product SubarraymediumArrayDynamic Programmingfrequency 37.7
- Partition Equal Subset SummediumArrayDynamic ProgrammingKnapsack Problem0-1 Knapsackfrequency 37.7
- Permutation in StringmediumHash TableTwo PointersStringSliding Windowfrequency 37.7
- Verifying an Alien DictionaryeasyArrayHash TableStringfrequency 37.7
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.