1Three Sum To ZeroArrays, Medium, Two Pointers
110Set Matrix ZeroesArrays, Medium
145Group AnagramsArrays, Medium
161Longest Palindromic SubstringMedium, String, Two Pointers
170Missing RangesArrays, Medium
176Increasing Triplet SubsequenceArrays, Medium
330Add Two LinkedListLinked List, Medium
382Odd-Even LinkedListLinked List, Medium
394Intersection of Two Linked ListsLinked List, Medium
449Binary Tree Inorder TraversalMedium, Stack, Tree
466Zigzag Traversal of Binary TreeBreadth First Search, Medium, Tree
474Binary Tree from Preorder and Inorder TraversalMedium, Recursion, Tree
481Kth Smallest Element in a BSTDepth First Search, Medium, Tree
490Inorder Successor in BSTMedium, Tree
644Inorder Predecessor In BSTMedium, Tree
649Product of Array Except SelfArrays, Hard
658Number Of IslandsDepth First Search, Flood Fill, Medium
666Spiral MatrixArrays, Hard, Recursion
726Letter Combination of Telephone NumbersBacktracking, Medium, Recursion
729Generate Balanced ParenthesesBacktracking, Medium, Subsets
745Permutations Of An Array (With Duplicate Sets)Arrays, Backtracking, Medium, Subsets
749Subsets Of An Array (With Duplicates Set)Arrays, Backtracking, Medium, Subsets
757Dutch National FlagArrays, Medium, Two Pointers
759Top K Frequent Elements in ArrayArrays, Medium, TopK
773Average of Contiguous Subarray of Size KArrays, Easy, Sliding Window
777Maximum Subarray Sum of Size KArrays, Easy, Sliding Window
780Smallest Contiguous Subarray with Sum SArrays, Medium, Sliding Window
784Longest Substring with K Distinct CharactersHard, Sliding Window, String
796Fruit Into BasketArrays, Medium, Sliding Window
801Longest Substring Without Repeating CharactersMedium, Sliding Window, String
819Minimum Window Pattern Matching SubstringHard, Sliding Window, String
824Maximum from Subarray of Size KArrays, Medium, Sliding Window
826Longest Repeating Character Substring after K ReplacementArrays, Medium, Sliding Window
832String Permutation Pattern MatchingArrays, Medium, Sliding Window
835Longest Subarray after replacing K ZeroArrays, Medium, Sliding Window
838Max Consecutive Ones in an ArrayArrays, Medium, Sliding Window
840Intersection of Three Sorted ArraysArrays, Easy, Two Pointers
844Squares of Sorted ArrayArrays, Easy, Two Pointers
847Reverse an ArrayArrays, Easy, Two Pointers
899Two Sum to TargetArrays, Easy, Two Pointers
901Intersection of Two Unsorted ArraysArrays, Easy, Two Pointers
903Remove selected element from the arrayArrays, Easy, Two Pointers
905Container With Most WaterArrays, Medium, Two Pointers
907Trapping Rain WaterArrays, Hard, Two Pointers
910Merge Sorted ArrayArrays, Easy, Two Pointers
914Three Sum Closest to TargetArrays, Medium, Two Pointers
917Move All Zeroes to End of ArrayArrays, Easy, Two Pointers
920Compare String with BackspaceArrays, Easy, Two Pointers
923Remove Duplicates from Sorted ArrayArrays, Easy, Two Pointers
926Subarray Product Less Than KArrays, Medium, Sliding Window, Two Pointers
943LinkedList CycleFast And Slow, Linked List, Medium
948Cycle in a Circular ArrayArrays, Fast And Slow, Medium
952Happy NumberArrays, Easy, Fast And Slow
954Middle of the LinkedListArrays, Easy, Fast And Slow
957Reorder LinkedList First and LastFast And Slow, Linked List, Medium
964Validate Palindromic LinkedListEasy, Fast And Slow, Linked List
968Merge Overlapping IntervalsMedium, Merge Intervals
973Insert Into Non-Overlapping IntervalsHard, Merge Intervals
975Find Interval IntersectionsMedium, Merge Intervals
982Conflicting MeetingsEasy, Medium, Merge Intervals
986Minimum Meeting RoomsMedium, Merge Intervals
991Meeting SchedulerMedium, Merge Intervals
997Remove From Non-Overlapping IntervalsMedium, Merge Intervals
999Employee Free Time From Busy IntervalsHard, Merge Intervals
1004Cyclic Array SortArrays, Cyclic Sort, Easy
1006Find Missing Number in ArrayArrays, Cyclic Sort, Easy
1010Find All Missing Numbers in ArrayArrays, Cyclic Sort, Medium
1015Find Duplicate Number in ArrayArrays, Cyclic Sort, Fast And Slow, Medium
1020Find All Duplicates in ArrayArrays, Cyclic Sort, Medium
1022Find First Missing Positive Number In ArrayArrays, Cyclic Sort, Hard
1024Find Duplicate And Missing Number in ArrayArrays, Cyclic Sort, Hard
1028Find First K Missing Positive Numbers in ArrayArrays, Cyclic Sort, Hard
1037Topological SortGraph, Medium, Topological Sort
1041Course SchedulingGraph, Medium, Topological Sort
1049Course Scheduling With OrderGraph, Medium, Topological Sort
1053All Course Scheduling OrdersGraph, Hard, Topological Sort
1062Course Scheduling In Preference Of TimeDynamic Programming, Hard, Recursion
1066Alien DictionaryGraph, Hard, Topological Sort
1070Sequence ReconstructionGraph, Medium, Topological Sort
1077Minimum Height TreeGraph, Medium, Topological Sort
1099Valid ParenthesisEasy, Stack, String
1102Next PermutationArrays, Two Pointers
1113Permutation of Array (Removing Duplicate Sets)Arrays, Backtracking, Medium, Subsets
1116Level Order TraversalBreadth First Search, Medium, Tree
1120Lever Order Traversal From Leaf to RootBreadth First Search, Medium, Tree
1125Level Order Traversal With Level AverageBreadth First Search, Medium, Tree
1129Vertical Order TraversalDepth First Search, Medium, Tree
1132Level Order Traversal of N-Ary TreeBreadth First Search, Medium, Tree
1135Binary Tree Traversal Using StackMedium, Stack, Tree
1143Tree Traversal Using RecursionMedium, Recursion, Tree
1147Minimum Depth of Binary TreeBreadth First Search, Medium, Tree
1151Maximum Depth of Binary TreeBreadth First Search, Depth First Search, Medium, Tree
1157Right Side View Of Binary TreeBreadth First Search, Medium, Tree
1161Left Side View of Binary TreeBreadth First Search, Medium, Tree
1166Find Leaves of Binary Tree Until Tree Is EmptyDepth First Search, Medium, Tree
1173Flood FillDepth First Search, Easy, Flood Fill
1177Greatest Common Divisor Of StringsEasy, Recursion, String
1180Time Based Key-Value StoreDesign, Hash Table, Medium
1185Rank Team By VotesArrays, Medium
1188Lemonade ChangeArrays, Easy
1191Hit CounterDesign, Hash Table, Queue
1195Logger Rate LimiterDesign, Easy, Queue
1202Evaluate Expression in Reverse Polish NotationArrays, Easy, Stack
1213HashMap in JavaDesign, Hash Table, Linked List, Medium
1221Design a Peeking IteratorDesign, Medium
1224Leaves of Binary Tree From Left to RightDepth First Search, Easy, Tree
1227Leaf Similar TreesDepth First Search, Medium, Tree
1232Maximum Average of a SubtreeDepth First Search, Medium, Tree
1235Binary Tree Iterator (Inorder)Binary Search Tree, Design, Medium, Stack
1242Total Number of Friend CircleBreadth First Search, Depth First Search, Medium
1252What is a GraphGraph
1262Undirected Graph Using Adjacency ListEasy, Graph
1269Directed Graph using Adjacency ListEasy, Graph
1279Undirected Graph using Adjacency MatrixEasy, Graph
1281Directed Graph using Adjacency MatrixEasy, Graph
1306BFS Traversal Of Undirected Graph using Adjacency ListBreadth First Search, Graph, Medium
1309BFS Traversal of Directed Graph using Adjacency ListBreadth First Search, Graph, Medium
1312DFS Traversal Of Undirected Graph using Adjacency ListDepth First Search, Graph, Medium
1315DFS Traversal Of Directed Graph using Adjacency ListDepth First Search, Graph, Medium
1324BFS Traversal Of Undirected Graph using Adjacency MatrixBreadth First Search, Graph, Medium
1329BFS Traversal Of Directed Graph using Adjacency MatrixBreadth First Search, Graph, Medium
1337DFS Traversal Of Undirected Graph using Adjacency MatrixDepth First Search, Graph, Medium
1339DFS Traversal Of Directed Graph using Adjacency MatrixDepth First Search, Graph, Medium
1345Number of Connected Components in an Undirected GraphBreadth First Search, Graph, Medium
1356Object-Oriented Programming And ConceptsDesign
1375Java Common ConceptsDesign
1388Collection Framework in JavaDesign
1399Reverse a LinkedListEasy, Linked List
1401Reverse a Sub List from LinkedListLinked List, Medium
1403Reverse Every K Sized Sub ListHard, Linked List
1408Reverse Every K Sized Sub List Except LastHard, Linked List
1412Delete Node in a LinkedListEasy, Linked List
1414Remove All Nodes With Given Value From LinkedListEasy, Linked List
1417Remove Alternating K Elements From LinkedListHard, Linked List
1421Find Maximum Overlapping Interval and Overlapping PointMedium, Merge Intervals
1427Iterator in JavaDesign
1432Quick Sort AlgorithmArrays, Easy, Sorting
1435Kth Largest Element in an ArrayArrays, Medium, TopK
1437Median of an Unsorted ArrayArrays, Medium
1439Consistent Hashing in JavaDesign, Hash Table
1443Iterable in JavaDesign
1450ArrayList in JavaArrays, Design
1455LinkedList in JavaDesign, Linked List
1458Stack in JavaDesign, Stack
1462PriorityQueue in JavaDesign, Queue
1464HashSet in JavaArrays, Design
1466TreeSet in JavaDesign
1470LinkedHashSet in JavaDesign
1483Vector In JavaDesign
1502Pass By Value and Pass By ReferenceDesign
1507Java Memory Model and Garbage CollectionDesign
1514Find Median from Continuous Data StreamDesign, Hard, Two Heaps
1521Sliding Window MedianHard, Sliding Window, Two Heaps
1526Moving Average from Data StreamEasy, Sliding Window
1529Validate Next IntervalHard, Two Heaps
1534Top K Largest Elements in ArrayArrays, Medium, TopK
1537Kth Smallest Element in an ArrayArrays, Medium, TopK
1544K Closest Points to OriginMedium, TopK
1551Complexity Cheat SheetDesign, Medium
1559Sort Characters By FrequencyMedium, String, TopK
1564Find K Closest Elements to X in an ArrayBinary Search, TopK, Two Pointers
1567Rearrange StringMedium, String, TopK
1576Rearrange String k Distance ApartHard, String, TopK
1578Task SchedulerArrays, Hard, TopK
1582Maximum Frequency StackDesign, Hard, Stack, TopK
1597Subset of an Array (Removing Duplicate Sets)Arrays, Backtracking, Medium, Subsets
1619Letter Case PermutationMedium, String, Subsets
1627Combination SumArrays, Medium, Subsets
1631Combination Sum without DuplicatesArrays, Medium, Subsets
1647Evaluate All Answers For ExpressionDynamic Programming, Hard, Subsets
1651Introduction to ThreadsDesign, Thread
1660Multithreading in JavaDesign, Thread
1662Synchronized in JavaDesign, Thread
1667How To Create Thread In JavaDesign, Thread
2035Web Application : Basic ConceptsDesign
2078Object Pool Design PatternDesign
2099Shortest Distance to a CharacterEasy, String
2109Frequency Count of All Possible Item SetsHard, Hash Table, Subsets
2129Queue in JavaLinked List, Medium, Queue
2135LinkedHashMap in JavaDesign, Hash Table, Medium
2140Skyline ProblemArrays, Hard, Merge Intervals
2149Single Element in a Sorted ArrayArrays, Binary Search, Medium
2154Level Order Successor in Binary TreeBreadth First Search, Easy, Tree
2156Connect Level Order SiblingsBreadth First Search, Medium, Tree
2159Connect All Level Order Siblings in Binary TreeBreadth First Search, Medium, Tree
2179Find Path (Root to Leaf) With Sum In Binary TreeDepth First Search, Easy, Tree
2181All Path Sum for Binary TreeDepth First Search, Medium, Tree
2184Count Total Paths For Sum in Binary TreeDepth First Search, Medium, Tree
2187Breadth First Search Traversal of Binary TreeBreadth First Search, Easy, Tree
2190Depth First Search Traversal of Binary TreeDepth First Search, Easy, Tree
2193All Paths From Root to Leaf in Binary TreeDepth First Search, Medium, Tree
2196Path With Given SequenceDepth First Search, Medium, Tree
2199Diameter of Binary Tree (Longest path between any Two Nodes)Depth First Search, Medium, Tree
22020-1 Knapsack ProblemDynamic Programming, Hard
2206Find Subset With SumDynamic Programming, Medium
2213Binary SearchBinary Search, Easy
2218Search in a Sorted Array of Unknown SizeBinary Search, Medium
2220Peak Index in Mountain ArrayBinary Search, Easy
2223Magic Index or Fixed Point in ArrayBinary Search, Easy
2226Binary Search with Order-Agnostic ArrayBinary Search, Easy
2230Largest Element Smaller than Target in ArrayBinary Search, Medium
2233Smallest Element Greater than Target in ArrayBinary Search, Medium
2235Find Smallest Letter Greater Than Target in ArrayBinary Search, Medium
2242Find First and Last Position of Element in Sorted ArrayBinary Search, Medium
2248Closest Element in ArrayBinary Search, Medium
2257Search in Mountain ArrayBinary Search Tree, Medium
2260Search in Circular Array (Rotated Sorted Array)Binary Search, Medium
2264Equal Subset Sum PartitionDynamic Programming, Medium
2268Count subsets with sum equal to XDynamic Programming, Medium
2271Unbounded KnapsackDynamic Programming, Medium
2273Rotate Array by K StepsArrays, Easy
2275Search a 2D MatrixArrays, Binary Search, Medium
2278Merge K Sorted ListsHard, K Way Merge
2286Kth Smallest Element in M ArraysHard, K Way Merge
2291Kth Smallest Element in Sorted MatrixBinary Search, Hard, K Way Merge
2300Smallest Range Covering Elements from K ListsHard, K Way Merge
2303Find Median in M Sorted ArrayHard, K Way Merge
2305Median of Two Sorted ArraysBinary Search, Hard
2320REST API : Basics and How to Use itDesign
2341N-ary Tree TraversalDepth First Search, Easy, Tree
2347Maximum Depth of N-ary TreeBreadth First Search, Depth First Search, Easy, Tree
2351Encode N-ary Tree to Binary TreeDepth First Search, Hard, Tree
2363Serialize and Deserialize N-ary TreeDepth First Search, Hard, Tree
2368Serialize Deserialize a Binary TreeDepth First Search, Hard, Tree
2381Relative Sort ArrayArrays, Easy
2388Custom Sort StringArrays, Medium
2398Maximize CapitalHard, Two Heaps
2403Find Next Right IntervalHard, Two Heaps
2410LRU CacheDesign, Medium
2417LFU CacheDesign, Hard
2425ConcurrentHashMap in JavaDesign, Hard
2442Sort HashMap by ValueEasy, Hash Table
2447Coin Change Count Min CoinsDynamic Programming, Medium
2453Coin Change Count Total WaysDynamic Programming, Medium
2460Coin Change Count Max CoinsDynamic Programming, Medium
2467Fibonacci NumberDynamic Programming, Easy
2470Merge SortArrays, Easy, Sorting
2478External SortingDesign, Hard, Sorting
2594System Design YoutubeDesign
2602Quad TreeDepth First Search, Flood Fill, Hard, Tree
2614Lowest Common Ancestor of Binary TreeDepth First Search, Medium, Tree
2655Check Completeness of Binary TreeBreadth First Search, Medium, Tree
2700Perfect Rectangle CoverHard
2706Maximum Sum of Two Non-Overlapping SubarraysArrays, Medium
2722Word Search in MatrixBacktracking, Depth First Search, Flood Fill, Medium
2727All Words Search In Matrix – Boggler ProblemBacktracking, Depth First Search, Flood Fill, Hard, Trie
2733Trie or Prefix TreeMedium, Tree, Trie
2741Snakes and LaddersBacktracking, Breadth First Search, Medium
2800Flatten Nested List IteratorDesign
2809Word Break ProblemDynamic Programming, Medium, Recursion
2813Word Break – Find All WordsDynamic Programming, Hard, Recursion
2835Design Tic Tac ToeArrays, Design, Medium
2851Abstract Factory Design PatternDesign
2858Builder PatternDesign
2869Prototype Design PatternDesign
2876Singleton Design PatternDesign
2895Application TiersDesign
2909Client Server ArchitectureDesign
2913SOAP and RESTDesign
2922HTTP Push and HTTP Pull MechanismDesign
2965CAP TheoremDesign
2971Proxy ServerDesign
2976Load BalancerDesign
2983What happens when user types URL in the BrowserDesign
3002Relational and Non Relational DatabaseDesign
3008ACID vs BASE PropertyDesign
3010Database Consistency PatternsDesign
3016Database Sharding or PartitioningDesign
3025Types of NOSQL DatabaseDesign
3053How HTTPS Works?Design, Hard
3091Vertical Order Traversal sorted by Level and ValueDepth First Search, Hard, Tree
3095Decode WaysDynamic Programming, Hard
3111Verify in Alien DictionaryEasy, String
3114Minimum Remove to make Valid Parenthesis in StringMedium, Stack
3116Count Total Consecutive Subarray Whose Sum Equals KArrays, Hash Table, Medium
3119Validate Palindrome by Removing One CharacterEasy, String, Two Pointers
3124Leftmost Column with at Least a OneArrays, Medium
3129Add Strings of IntegerEasy, Numbers
3138Design Add and Search Words Data StructureDesign, Medium
3144Minimum Remove to make Valid Parenthesis (Get All Combination)Backtracking, Hard, String
3155Range Sum of Binary Search TreeBinary Search Tree, Depth First Search, Easy
3158All String Anagram Pattern MatchingMedium, Sliding Window
3161Binary Tree Maximum Path Sum (Any Start to End)Depth First Search, Tree
3164Expression Operators Combination to Get TargetBacktracking, Hard, Subsets
3167Validate String Palindrome Skipping Special CharactersEasy, Two Pointers
3174Random Index Pick with WeightBinary Search, Medium, Random
3188Architecture Options for Multiple DatacenterDesign
3195Insert Delete GetRandom O(1) – With DuplicatesDesign
3200Insert Delete GetRandom O(1) – Without DuplicatesDesign, Medium
3206Flatten Binary Tree to Linked ListDepth First Search, Medium, Tree
3214Decode Ways With Special CharacterDynamic Programming, Hard
3221Largest SubMatrix with All Border 1Arrays, Medium
3224Regular Expression Wildcard Pattern MatchingDynamic Programming, Hard
3229Remove Comments from String of CodeEasy, String
3246All Nodes at k Distance from Target NodeBreadth First Search, Depth First Search, Medium, Tree
3250CombinationsMedium, Subsets
3270Design Circular Queue (RingBuffer)Design, Medium
3272Design Circular DequeDesign, Medium
3289Longest Increasing SubsequenceDynamic Programming, Medium
3295Partition a LinkedList by TargetLinked List, Medium
3298String CompressionMedium, Sliding Window
3302Repeated DNA SequencesMedium, Sliding Window
3304Largest Square Submatrix With All 1Dynamic Programming, Medium
3310Remove Duplicates And Original From Sorted LinkedListLinked List, Medium, Two Pointers
3317Search in Circular Array With DuplicatesBinary Search, Medium
3322Four SumMedium, Two Pointers
3333Word LadderDepth First Search, Medium
3337Gas Station or Petrol Filling ProblemArrays, Medium
3352Introduction to Union Find or Disjoint SetUnion Find
3379Cycle in Undirected Graph Using Disjoint SetGraph, Union Find
3384Cycle in Graph Using Union By Rank with Path CompressionGraph, Union Find
3391Find if A is Friend of BUnion Find
3399Earliest Time When All are FriendsMedium, Union Find
3409Shortest Distance from All Building in GridBreadth First Search, Hard
3416Find K Pairs with Smallest SumsArrays, Medium
3424Maximum Subarray SumEasy, Sliding Window
3434Max Value StackDesign, Medium, Stack
3441Can Place Neighboring 1’s in ArrayArrays, Easy
3460Min Value StackDesign, Easy
3463Design Bounded Blocking QueueDesign, Medium
3479Shuffle an ArrayArrays, Medium
3487Nim GameBacktracking, Easy, minimax
3501Flip GameEasy, minimax
3505Predict the WinnerDynamic Programming, Medium, minimax
3515100 Game – Without Reusing IntegersDynamic Programming, Medium, minimax
3520Climbing StairsDynamic Programming, Easy
3532HTTP AttacksDesign, Hard
3544Operating System in NutshellDesign, Hard
3568Computer Networks in NutshellDesign
3594Design RESTful Shopping CartDesign, Hard, System Design
3623Continuous Subarray SumArrays, Medium
3627Max Area Of A IslandDepth First Search, Flood Fill
3629Design Browser HistoryDesign, Hard
3641Nested List Weight SumDesign, Easy
3647How to make a Service Scalable?Design, Hard
3664Distributed TransactionsDesign, Hard
3690Divide Two IntegersMedium, Numbers
3705Power Of XEasy, Numbers
3711Validate Decimal StringHard, Numbers
3717Add Binary StringBitwise, Easy
3721Clone Graph (Deep Copy Graph)Graph, Medium
3752Find Closest Node in BSTBinary Search Tree, Easy
3776Random VariablesEasy, Random
3785Randomized AlgorithmEasy, Random
3791Binomial Random VariablesEasy, Random
3797Implement Random7 Using Random5Medium, Random
3812Implement Random10 Using Random 7Easy, Random
3817Shuffle a Given Array or Deck Of CardsMedium, Random
3826Reservoir SamplingEasy, Random
3832Random Number From StreamMedium, Random
3838Random Pick IndexMedium, Random
3849Convert BST To Sorted Doubly Linked List
3902Domain Name SystemDesign, Medium
3917Content Distribution Network (CDN)Design, Medium
3928AsynchronismDesign, Medium
3937Tweet Counts Per FrequencyDesign, Hash Table, Medium
3949Maximum One Swap For Max Valued Number
3962Insert Value in Sorted Circular LinkedListLinked List, Medium
3970Insert Value in Sorted LinkedListLinked List, Medium
3980Accounts MergeMedium, Union Find
4026Design Instagram (Photo Sharing Social Network)Design, System Design
4083Copy LinkedList with Random PointerLinked List, Medium
4089Validate Binary Search TreeBinary Search Tree, Easy
4092Remove K Consecutive CharactersMedium, Stack, String
4108Lexicographically Smallest String From Root To Leaf in Binary TreeDepth First Search, Medium
4127Is Graph Bipartite ?Graph, Medium
4162Design Web CrawlerDesign, Medium, System Design
4189Design TwitterDesign, Hard, System Design
4368Design Kubernates (Application Deployment Management System)Design, Hard, System Design
4419Design Twitter (User Tweet Feed And Follow)Design, Medium
4441Making A Large Island (Replacing/Swapping One Zero with One)Flood Fill, Hard
4473Total Subsequence with Min and Max Less Than TargetMedium, Two Pointers
4544Shortest Palindrome By Adding CharacterHard, String
4551Design Autocomplete SystemDesign, Hard, System Design
4642Wildcard Pattern Matching
4657Dot Product of Two Sparse VectorsArrays, Medium
4694Distributed Ledger Technology (Blockchain)
4845Design WhatsAppDesign, Hard, System Design
4855Deciding Best Storage SolutionDesign, Hard, System Design
4954Group All Shifted String TogetherArrays, Medium
4962Merging IteratorDesign, Hard
5007Average of Each Subtree Excluding NodeDepth First Search, Medium
5015Group Duplicate File In SystemArrays, Medium
5026Wrap Sentence in Limit Length (Word Wrap)Hard
5034Basic CalculatorMedium, Numbers
5038Basic Calculator (Including Parenthesis)Hard, Numbers
5050Design Google MapsDesign, Hard, System Design
5062Delete Given Node From LinkedListEasy, Linked List
5079Largest BST Subtree in Binary TreeBinary Search Tree, Depth First Search
5084Friends Of Appropriate Ages (Count Friend Request)Arrays, Medium
5106Absolute Path to Canonical PathMedium, String
5119Cracking the Safe
5128De Bruijn Sequence (Inverse Burrows Wheeler Transform)Hard, String
5132Hash Table Using ChainingDesign, Hash Table, Medium
5144Binary Tree Iterator II (Inorder)Binary Search Tree, Design, Medium
5149Maximum Sum of Three Non Overlapping SubarraysArrays, Dynamic Programming, Hard
5153Minimum Stickers to Generate WordDynamic Programming, Hard
5160Natural Sorting ComparatorDesign, Hard
5165Balance a Binary Search TreeBinary Search Tree, Medium
5189Design UberDesign, Hard, System Design
5203Design DropboxDesign, Hard, System Design
5233Design Twitter Search
5258Design LeaderboardDesign, Hard, System Design
5292Design Google AdsDesign, Hard, System Design
5334Lowest Common Ancestor in Undirected GraphGraph, Hard
5369Design Google TranslateDesign, Hard, System Design
5436Design YelpDesign, Hard, System Design

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