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Add BinaryTopics:StringMath & Geometry+2easy Balanced Binary TreeTopics:BFS / DFSTreeseasy Best Time to Buy and Sell StockTopics:Arrays & HashingSliding Windoweasy Binary SearchCompanies:Square (Block)Topics:Arrays & HashingBinary Searcheasy Climbing StairsTopics:Dynamic ProgrammingMath & Geometryeasy Contains DuplicateTopics:Arrays & Hashingeasy Counting BitsTopics:Dynamic ProgrammingBit Manipulationeasy Diameter of Binary TreeCompanies:MetaCoinbaseTopics:TreesBFS / DFSeasy First Bad VersionTopics:Binary Searcheasy Flood FillCompanies:CoinbaseTopics:Arrays & HashingBFS / DFSeasy Happy NumberTopics:Arrays & HashingTwo Pointers+1easy Implement Queue using StacksCompanies:TikTok (ByteDance)Topics:DesignStackeasy Invert Binary TreeTopics:BFS / DFSTreeseasy Kth Largest Element in a StreamTopics:TreesHeap / Priority Queue+1easy Largest Local Values in a MatrixTopics:Arrays & HashingSimulationeasy Last Stone WeightCompanies:NVIDIATopics:Arrays & HashingHeap / Priority Queueeasy Linked List CycleCompanies:NetflixDropboxFigmaTopics:Linked ListTwo Pointerseasy Longest Palindrome LengthTopics:Arrays & HashingString+1easy Majority ElementCompanies:SnapRampTopics:Arrays & Hashingeasy Maximum Depth of Binary TreeCompanies:InstacartTopics:BFS / DFSTreeseasy Meeting RoomsTopics:Arrays & HashingHeap / Priority Queue+2easy Merge Two Sorted ListsCompanies:MicrosoftTopics:Linked Listeasy Middle of the Linked ListTopics:Linked ListTwo Pointerseasy Min Cost Climbing StairsTopics:Arrays & HashingDynamic Programmingeasy Missing NumberTopics:Arrays & HashingBinary Search+2easy Number of 1 BitsTopics:Bit Manipulationeasy Plus OneCompanies:DatadogTopics:Arrays & HashingMath & Geometryeasy Ransom NoteTopics:Arrays & HashingStringeasy Reverse BitsTopics:Bit Manipulationeasy Reverse Linked ListCompanies:AppleMicrosoftNetflix+7Topics:Linked Listeasy Same TreeCompanies:SpotifyCloudflareTopics:BFS / DFSTreeseasy Single NumberTopics:Arrays & HashingBit Manipulationeasy Subtree of Another TreeTopics:StringTrees+2easy Two SumCompanies:GoogleAmazonMicrosoft+10Topics:Arrays & HashingTwo Pointerseasy Valid AnagramCompanies:SpotifyTopics:Arrays & HashingStringeasy Valid PalindromeCompanies:RampSupabaseTopics:StringTwo Pointerseasy Valid ParenthesesCompanies:GoogleAppleMicrosoft+8Topics:StackStringeasy 3SumTopics:Arrays & HashingTwo Pointersmedium Accounts MergeCompanies:MetaDropboxPinterest+3Topics:Arrays & HashingString+2medium Add Two NumbersCompanies:DatabricksTopics:Linked ListMath & Geometrymedium Analytics: Longest Unique Session WindowCompanies:GoogleAmazonMicrosoft+9Topics:Sliding WindowStringmedium Asteroid CollisionTopics:Arrays & HashingStack+1medium Binary Tree Level Order TraversalCompanies:AmazonMicrosoftCohere+3Topics:BFS / DFSTreesmedium Binary Tree Right Side ViewCompanies:MetaNVIDIALyft+1Topics:BFS / DFSTreesmedium Car FleetTopics:Arrays & HashingStackmedium Cheapest Flights Within K StopsTopics:Arrays & HashingGraphs+3medium Clone GraphCompanies:GoogleSnowflakeSquare (Block)+1Topics:GraphsBFS / DFSmedium Coin ChangeCompanies:GoogleAmazonMicrosoft+7Topics:Arrays & HashingDynamic Programming+1medium Coin Change IICompanies:OpenAIPalantirReddit+4Topics:Arrays & HashingDynamic Programmingmedium Combination SumCompanies:Scale AIPinterestBloomberg+1Topics:Arrays & HashingBacktrackingmedium Combination Sum IICompanies:SalesforceLinkedInTopics:Arrays & HashingBacktrackingmedium Construct Binary Tree from Preorder and Inorder TraversalTopics:Arrays & HashingTrees+1medium Container With Most WaterCompanies:NetflixSalesforcePalantir+2Topics:Arrays & HashingTwo Pointers+1medium Copy List with Random PointerCompanies:MetaAnthropicSnap+1Topics:Linked ListArrays & Hashingmedium Count Good Nodes in Binary TreeTopics:BFS / DFSTreesmedium Course ScheduleCompanies:GoogleAmazonApple+16Topics:BFS / DFSGraphs+1medium Course Schedule IICompanies:AppleSnowflakeDoorDashTopics:BFS / DFSGraphsmedium Daily TemperaturesCompanies:SnowflakeTikTok (ByteDance)PlaidTopics:Arrays & HashingStackmedium Decode WaysCompanies:GoogleTopics:StringDynamic Programmingmedium Design Add and Search Words Data StructureCompanies:AppleTopics:StringTrees+2medium Design Memory AllocatorTopics:DesignSimulationmedium Design TwitterCompanies:Twitter/XTopics:Arrays & HashingLinked List+2medium Detect SquaresTopics:Arrays & HashingDesignmedium Distance to Nearest ZeroTopics:Arrays & HashingBFS / DFSmedium Edit DistanceTopics:Dynamic ProgrammingStringmedium Encode and Decode StringsTopics:DesignStringmedium Equal Sum Array PartitionTopics:Arrays & HashingDynamic Programmingmedium Evaluate Reverse Polish NotationTopics:Arrays & HashingStack+1medium Find All Anagrams in a StringTopics:Arrays & HashingString+1medium Find Minimum in Rotated Sorted ArrayTopics:Arrays & HashingBinary Searchmedium Find the Duplicate NumberCompanies:NetflixTopics:Arrays & HashingTwo Pointers+2medium Gas StationCompanies:PalantirTikTok (ByteDance)Airbnb+1Topics:Arrays & HashingGreedymedium Generate ParenthesesCompanies:RobinhoodPlaidRamp+1Topics:StringBacktracking+1medium Graph Valid TreeTopics:BFS / DFSGraphsmedium Group AnagramsCompanies:OpenAIDropboxSpotify+2Topics:Arrays & HashingStringmedium Hand of StraightsTopics:Arrays & HashingGreedymedium House RobberCompanies:TwitchTopics:Arrays & HashingDynamic Programmingmedium House Robber IICompanies:Scale AIPalantirLyftTopics:Arrays & HashingDynamic Programmingmedium Implement Trie (Prefix Tree)Companies:AnthropicDeepMindCursor+4Topics:Arrays & HashingString+2medium In-Memory SQL EngineTopics:DesignSimulationmedium Insert IntervalTopics:Arrays & HashingIntervalsmedium Interleaving StringTopics:Dynamic ProgrammingStringmedium IPv4 Iterators and CIDRTopics:Bit ManipulationMath & Geometrymedium Jump GameCompanies:TikTok (ByteDance)Topics:Arrays & HashingDynamic Programming+1medium Jump Game IITopics:Arrays & HashingDynamic Programming+1medium K Closest Points to OriginCompanies:MetaScale AISalesforce+6Topics:Arrays & HashingHeap / Priority Queue+2medium K Radius Subarray AveragesCompanies:DuolingoTopics:Arrays & HashingSliding Windowmedium Koko Eating BananasCompanies:PalantirDoorDashTopics:Arrays & HashingBinary Searchmedium Kth Largest Element in an ArrayCompanies:MetaNetflixPalantir+4Topics:Arrays & HashingHeap / Priority Queue+1medium Kth Smallest Element in a BSTCompanies:LyftNotionTopics:BFS / DFSTreesmedium Letter Combinations of a Phone NumberCompanies:InstacartTopics:Arrays & HashingString+1medium Longest Common SubsequenceCompanies:AmazonTopics:StringDynamic Programmingmedium Longest Consecutive SequenceCompanies:SnapInstacartBloomberg+2Topics:Arrays & HashingGraphsmedium Longest Increasing SubsequenceCompanies:DeepMindStripeTopics:Arrays & HashingBinary Search+1medium Longest Palindromic SubstringCompanies:MicrosoftDatabricksShopifyTopics:StringTwo Pointers+1medium Longest Repeating Character ReplacementCompanies:OpenAIDropboxTikTok (ByteDance)+1Topics:Arrays & HashingString+2medium Lowest Common Ancestor of a Binary Search TreeCompanies:PalantirLinkedInTopics:BFS / DFSTreesmedium Lowest Common Ancestor of a Binary TreeCompanies:GoogleAmazonMeta+2Topics:BFS / DFSTreesmedium LRU CacheCompanies:AmazonAppleNetflix+21Topics:Arrays & HashingDesign+1medium Max Area of IslandTopics:Arrays & HashingBFS / DFS+1medium Maximum Product SubarrayCompanies:Scale AISalesforceSnowflake+1Topics:Arrays & HashingDynamic Programmingmedium Maximum SubarrayCompanies:AmazonAppleNetflix+4Topics:Arrays & HashingDynamic Programmingmedium Meeting Rooms IICompanies:AppleSalesforcePalantir+9Topics:Arrays & HashingHeap / Priority Queue+3medium Merge IntervalsCompanies:GoogleAmazonMeta+17Topics:Arrays & HashingIntervalsmedium Merge Triplets to Form Target TripletTopics:Arrays & HashingGreedymedium Min Cost to Connect All PointsTopics:Arrays & HashingGraphs+2medium Min StackCompanies:NVIDIADiscordInstacart+1Topics:DesignStackmedium Minimum Height TreesTopics:BFS / DFSGraphsmedium Minimum Number of People to TeachCompanies:DuolingoTopics:Arrays & HashingGreedymedium Multiply StringsTopics:Math & GeometryStringmedium Network Delay TimeTopics:BFS / DFSGraphs+1medium Non-overlapping IntervalsTopics:Arrays & HashingDynamic Programming+2medium Number of Connected Components in an Undirected GraphTopics:BFS / DFSGraphsmedium Number of IslandsCompanies:GoogleAmazonMicrosoft+18Topics:Arrays & HashingGraphs+1medium Pacific Atlantic Water FlowTopics:Arrays & HashingGraphs+1medium Palindrome PartitioningTopics:StringBacktracking+1medium Palindromic SubstringsCompanies:CoinbaseDatadogTopics:StringTwo Pointers+1medium Partition LabelsTopics:Arrays & HashingGreedy+2medium Permutation in StringTopics:Arrays & HashingSliding Window+2medium PermutationsCompanies:Scale AIPayPalTopics:Arrays & HashingBacktrackingmedium Pow(x, n)Topics:Math & Geometrymedium Product of Array Except SelfCompanies:GoogleAppleMicrosoft+6Topics:Arrays & Hashingmedium Redundant ConnectionTopics:Arrays & HashingBFS / DFS+1medium Remove Nth Node From End of ListCompanies:SalesforceInstacartTopics:Linked ListTwo Pointersmedium Reorder ListTopics:Linked ListStack+1medium Reverse IntegerTopics:Math & Geometrymedium Rotate ImageCompanies:NVIDIADiscordTopics:Arrays & HashingMath & Geometrymedium Rotting OrangesCompanies:MicrosoftDatabricksTesla+1Topics:Arrays & HashingBFS / DFS+1medium Search a 2D MatrixCompanies:Scale AITeslaDropbox+2Topics:Arrays & HashingBinary Searchmedium Search in Rotated Sorted ArrayCompanies:MicrosoftNVIDIACloudflareTopics:Arrays & HashingBinary Searchmedium Set Matrix ZeroesTopics:Arrays & Hashingmedium Simplify PathTopics:StackStringmedium Snack Bin Iterator — Flatten Nested ListsTopics:DesignStackmedium Sort ColorsCompanies:DropboxCoinbaseTopics:Arrays & HashingTwo Pointersmedium Spiral MatrixCompanies:AppleUberDatadogTopics:Arrays & HashingSimulationmedium Stock Trading with CooldownTopics:Arrays & HashingDynamic Programmingmedium String to Integer ConversionTopics:Stringmedium SubsetsCompanies:SalesforceSnowflakeTwilioTopics:Arrays & HashingBacktracking+1medium Subsets IITopics:Arrays & HashingBacktracking+1medium Sum of Two IntegersTopics:Math & GeometryBit Manipulationmedium Surrounded RegionsTopics:Arrays & HashingBFS / DFS+1medium Target SumTopics:Arrays & HashingBacktracking+1medium Task SchedulerCompanies:AnthropicSnapReddit+4Topics:Arrays & HashingGreedy+1medium Task Scheduler IICompanies:DuolingoTopics:Arrays & HashingSimulationmedium Telemetry: Top K Frequent Error CodesCompanies:NetflixCohereTesla+7Topics:Arrays & HashingHeap / Priority Queuemedium Time Based Key-Value StoreCompanies:AppleOpenAISnowflake+1Topics:Arrays & HashingBinary Search+1medium Two Sum II - Input Array Is SortedTopics:Arrays & HashingTwo Pointersmedium Unique PathsCompanies:NVIDIACloudflareTopics:Dynamic ProgrammingMath & Geometrymedium Valid Parenthesis StringTopics:StringStack+2medium Valid SudokuCompanies:OpenAIDropboxTopics:Arrays & Hashingmedium Validate Binary Search TreeCompanies:AmazonMicrosoftTopics:BFS / DFSTreesmedium Walls and GatesCompanies:RedditSpotifyDoorDashTopics:Arrays & HashingGraphs+1medium Web CrawlerTopics:StringGraphs+2medium Word BreakCompanies:AmazonMetaMicrosoft+9Topics:Arrays & HashingString+2medium Word SearchCompanies:UberPlaidAtlassian+1Topics:Arrays & HashingString+2medium Alien DictionaryCompanies:Twitter/XUberAirbnb+3Topics:Arrays & HashingString+2hard Basic CalculatorCompanies:SnowflakeDoorDashPlaid+1Topics:StringStack+1hard Binary Tree Maximum Path SumCompanies:SalesforceDiscordDoorDash+3Topics:TreesDynamic Programming+1hard Burst BalloonsTopics:Arrays & HashingDynamic Programminghard Carnival Concession InventoryTopics:Designhard Cloudflare Rate LimiterTopics:Designhard Design Excel Sum FormulaTopics:DesignGraphs+2hard Distinct SubsequencesTopics:Dynamic ProgrammingStringhard Encrypt and Decrypt StringsCompanies:DuolingoTopics:Arrays & HashingString+1hard Feature Flag Timeline StoreTopics:Designhard Figma Document BufferTopics:DesignSimulationhard Find Median from Data StreamCompanies:DeepMindCohereMistral+6Topics:Arrays & HashingHeap / Priority Queue+2hard GPU Credits ManagerTopics:Designhard Largest Rectangle in HistogramCompanies:DeepMindStripeSpotify+1Topics:Arrays & HashingStackhard Longest Increasing Path in a MatrixCompanies:TikTok (ByteDance)DoorDashPlaid+2Topics:Arrays & HashingGraphs+2hard Maximum Profit in Job SchedulingCompanies:TeslaPinterestDoorDashTopics:Arrays & HashingBinary Search+1hard Median of Two Sorted ArraysCompanies:NetflixDeepMindMistral+2Topics:Arrays & HashingBinary Searchhard Merge K Sorted ListsCompanies:DeepMindSnowflakeTwitter/X+3Topics:Linked ListHeap / Priority Queuehard Minimum Interval to Include Each QueryTopics:Arrays & HashingHeap / Priority Queue+3hard Minimum Window SubstringCompanies:GoogleAmazonAnthropic+1Topics:Arrays & HashingSliding Window+1hard N-QueensCompanies:OpenAIPalantirTwilioTopics:Arrays & HashingBacktrackinghard Pop-up Clinic Check-in TableTopics:Designhard Reconstruct ItineraryCompanies:PinterestTopics:BacktrackingBFS / DFS+1hard Regular Expression MatchingCompanies:MistralTwitter/XTikTok (ByteDance)+4Topics:StringBacktracking+1hard Reverse Nodes in k-GroupCompanies:SnapDiscordCoinbase+1Topics:Linked Listhard Robinhood Order BookTopics:DesignSimulationhard Serialize and Deserialize Binary TreeCompanies:GoogleAppleNetflix+8Topics:TreesDesign+1hard Sliding Window MaximumCompanies:Scale AISnowflakeSpotify+3Topics:Arrays & HashingStack+2hard Swim in Rising WaterTopics:Arrays & HashingGraphs+3hard Trapping Rain WaterCompanies:GoogleAmazonDeepMind+5Topics:Arrays & HashingStack+4hard Word LadderCompanies:GoogleSalesforceLinkedIn+1Topics:Arrays & HashingString+2hard Word Search IICompanies:DeepMindCursorTopics:Arrays & HashingString+3hard