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
348 questions at TikTok · all time
- Best Time to Buy and Sell Stock IVhardArrayDynamic Programmingfrequency 39.1
- Binary Tree Zigzag Level Order TraversalmediumTreeBreadth-First SearchBinary Treefrequency 39.1
- Convert Binary Search Tree to Sorted Doubly Linked ListmediumLinked ListStackTreeDepth-First Search+3frequency 39.1
- Design Memory AllocatormediumArrayHash TableDesignSimulationfrequency 39.1
- Design Search Autocomplete SystemhardStringDepth-First SearchDesignTrie+3frequency 39.1
- Design Tic-Tac-ToemediumArrayHash TableDesignMatrix+1frequency 39.1
- Find All Possible Recipes from Given SuppliesmediumArrayHash TableStringGraph Theory+2frequency 39.1
- Find the Length of the Longest Common PrefixmediumArrayHash TableStringTriefrequency 39.1
- House Robber IImediumArrayDynamic Programmingfrequency 39.1
- Kth Smallest Element in a Sorted MatrixmediumArrayBinary SearchSortingHeap (Priority Queue)+1frequency 39.1
- Longest Common SubsequencemediumStringDynamic ProgrammingLongest Common Subsequencefrequency 39.1
- Longest Substring with At Most Two Distinct CharactersmediumHash TableStringSliding Windowfrequency 39.1
- Make Costs of Paths Equal in a Binary TreemediumArrayDynamic ProgrammingGreedyTree+1frequency 39.1
- Max Consecutive Ones IIImediumArrayBinary SearchSliding WindowPrefix Sumfrequency 39.1
- Maximal SquaremediumArrayDynamic ProgrammingMatrixfrequency 39.1
- Maximum Product of Three NumberseasyArrayMathSortingfrequency 39.1
- Merge Operations to Turn Array Into a PalindromemediumArrayTwo PointersGreedyfrequency 39.1
- Minimum Cost For TicketsmediumArrayDynamic Programmingfrequency 39.1
- Number of Good Leaf Nodes PairsmediumTreeDepth-First SearchBinary TreeDP on Treesfrequency 39.1
- Number of Visible People in a QueuehardArrayStackMonotonic Stackfrequency 39.1
- Open the LockmediumArrayHash TableStringBreadth-First Search+1frequency 39.1
- Path Sum IIImediumTreeDepth-First SearchBinary Treefrequency 39.1
- Regions Cut By SlashesmediumArrayHash TableDepth-First SearchBreadth-First Search+3frequency 39.1
- Remove K DigitsmediumStringStackGreedyMonotonic Stackfrequency 39.1
- Robot Room CleanerhardBacktrackingInteractivefrequency 39.1
- Search a 2D MatrixmediumArrayBinary SearchMatrixfrequency 39.1
- Sentence Similarity IIImediumArrayTwo PointersStringfrequency 39.1
- Shortest Path in Binary MatrixmediumArrayBreadth-First SearchMatrixfrequency 39.1
- Snakes and LaddersmediumArrayBreadth-First SearchMatrixfrequency 39.1
- Swap Nodes in PairsmediumLinked ListRecursionfrequency 39.1
- Tree DiametermediumTreeDepth-First SearchBreadth-First SearchGraph Theory+2frequency 39.1
- Unique Paths IImediumArrayDynamic ProgrammingMatrixfrequency 39.1
- Accounts MergemediumArrayHash TableStringDepth-First Search+3frequency 33.0
- Add Bold Tag in StringmediumArrayHash TableStringTrie+2frequency 33.0
- All Nodes Distance K in Binary TreemediumHash TableTreeDepth-First SearchBreadth-First Search+1frequency 33.0
- Best Time to Buy and Sell Stock with CooldownmediumArrayDynamic Programmingfrequency 33.0
- Best Time to Buy and Sell Stock with Transaction FeemediumArrayDynamic ProgrammingGreedyfrequency 33.0
- CandyhardArrayGreedyfrequency 33.0
- Champagne TowermediumDynamic Programmingfrequency 33.0
- Coin Change IImediumArrayDynamic ProgrammingKnapsack ProblemComplete Knapsackfrequency 33.0
- Combination Sum IImediumArrayBacktrackingfrequency 33.0
- CombinationsmediumBacktrackingfrequency 33.0
- Contiguous ArraymediumArrayHash TablePrefix Sumfrequency 33.0
- Deepest Leaves SummediumTreeDepth-First SearchBreadth-First SearchBinary Treefrequency 33.0
- Delete and EarnmediumArrayHash TableDynamic Programmingfrequency 33.0
- Diameter of Binary TreeeasyTreeDepth-First SearchBinary TreeDP on Treesfrequency 33.0
- Find All Anagrams in a StringmediumHash TableStringSliding Windowfrequency 33.0
- Find the Duplicate NumbermediumArrayTwo PointersBinary SearchBit Manipulation+2frequency 33.0
- Flatten Deeply Nested Arraymediumfrequency 33.0
- Fruit Into BasketsmediumArrayHash TableSliding Windowfrequency 33.0
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.