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
1,223 questions at Bloomberg · all time
- Two SumeasyArrayHash Tablefrequency 100.0
- Merge IntervalsmediumArraySortingQuicksortfrequency 87.1
- Add Two NumbersmediumLinked ListMathRecursionfrequency 85.2
- Longest Substring Without Repeating CharactersmediumHash TableStringSliding Windowfrequency 85.1
- Insert Delete GetRandom O(1)mediumArrayHash TableMathDesign+1frequency 84.7
- Number of IslandsmediumArrayDepth-First SearchBreadth-First SearchUnion-Find+1frequency 84.7
- Best Time to Buy and Sell StockeasyArrayDynamic Programmingfrequency 83.9
- Valid ParentheseseasyStringStackBracket Sequencesfrequency 83.8
- Trapping Rain WaterhardArrayTwo PointersDynamic ProgrammingStack+1frequency 80.9
- 3SummediumArrayTwo PointersSortingfrequency 79.6
- Longest Palindromic SubstringmediumTwo PointersStringDynamic ProgrammingManacherfrequency 79.6
- Invalid TransactionsmediumArrayHash TableStringSortingfrequency 78.7
- Flatten a Multilevel Doubly Linked ListmediumLinked ListDepth-First SearchDoubly-Linked Listfrequency 78.5
- Longest Common PrefixeasyArrayStringTriefrequency 78.2
- Median of Two Sorted ArrayshardArrayBinary SearchDivide and Conquerfrequency 78.2
- Word SearchmediumArrayStringBacktrackingDepth-First Search+1frequency 77.8
- Container With Most WatermediumArrayTwo PointersGreedyfrequency 76.5
- Decode StringmediumStringStackRecursionfrequency 75.9
- Majority ElementeasyArrayHash TableDivide and ConquerSorting+2frequency 75.2
- Valid AnagrameasyHash TableStringSortingfrequency 75.2
- Merge Sorted ArrayeasyArrayTwo PointersSortingfrequency 74.6
- Reverse IntegermediumMathfrequency 74.6
- Palindrome NumbereasyMathfrequency 73.9
- Remove Duplicates from Sorted ArrayeasyArrayTwo Pointersfrequency 73.9
- LRU CachemediumHash TableLinked ListDesignDoubly-Linked Listfrequency 72.8
- Merge Two Sorted ListseasyLinked ListRecursionfrequency 72.0
- Design Underground SystemmediumHash TableStringDesignfrequency 71.8
- Longest Consecutive SequencemediumArrayHash TableUnion-Findfrequency 71.8
- Subarray Sum Equals KmediumArrayHash TablePrefix Sumfrequency 71.8
- Roman to IntegereasyHash TableMathStringfrequency 71.5
- Search in Rotated Sorted ArraymediumArrayBinary Searchfrequency 70.5
- Group AnagramsmediumArrayHash TableStringSortingfrequency 70.2
- Min StackmediumStackDesignfrequency 69.9
- SubsetsmediumArrayBacktrackingBit Manipulationfrequency 69.6
- Maximum SubarraymediumArrayDivide and ConquerDynamic Programmingfrequency 69.4
- Next PermutationmediumArrayTwo Pointersfrequency 69.4
- Climbing StairseasyMathDynamic ProgrammingMemoizationfrequency 67.2
- Move ZeroeseasyArrayTwo Pointersfrequency 67.2
- First Unique Character in a StringeasyHash TableStringQueueCountingfrequency 66.6
- Meeting Rooms IImediumArrayTwo PointersGreedySorting+2frequency 66.2
- Generate ParenthesesmediumStringDynamic ProgrammingBacktrackingBracket Sequencesfrequency 65.9
- Rotate ImagemediumArrayMathMatrixfrequency 65.9
- Reverse Linked ListeasyLinked ListRecursionfrequency 65.2
- Rotate ArraymediumArrayMathTwo Pointersfrequency 64.5
- Valid PalindromeeasyTwo PointersStringfrequency 64.5
- Validate Binary Search TreemediumTreeDepth-First SearchBinary Search TreeBinary Treefrequency 64.5
- Number of Ships in a RectanglehardArrayDivide and ConquerInteractivefrequency 64.1
- Single NumbereasyArrayBit Manipulationfrequency 63.3
- Word Break IIhardArrayHash TableStringDynamic Programming+3frequency 63.3
- Create Hello World Functioneasyfrequency 62.9
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.