1Word LadderHardHash TableStringBreadth-First Search
Solve → 2LRU CacheMediumHash TableLinked ListDesign
Solve → 3Word LadderHardHash TableStringBreadth-First Search
Solve → 4All Nodes Distance K in Binary TreeMediumHash TableTreeDepth-First Search
Solve → 5Design Task ManagerMediumHash TableDesignHeap (Priority Queue)
Solve → 6Time Based Key-Value StoreMediumHash TableStringBinary Search
Solve → 7LRU CacheMediumHash TableLinked ListDesign
Solve → 8Word LadderHardHash TableStringBreadth-First Search
Solve → 9Time Based Key-Value StoreMediumHash TableStringBinary Search
Solve → 10Longest Substring Without Repeating CharactersMediumHash TableStringSliding Window
Solve → 11Permutation in StringMediumHash TableTwo PointersString
Solve → 12Binary Tree Vertical Order TraversalMediumHash TableTreeDepth-First Search
Solve → 13Letter Combinations of a Phone NumberMediumHash TableStringBacktracking
Solve → 14Implement Trie (Prefix Tree)MediumHash TableStringDesign
Solve → 15Design Log Storage SystemMediumHash TableStringDesign
Solve → 16All Nodes Distance K in Binary TreeMediumHash TableTreeDepth-First Search
Solve → 17All O`one Data StructureHardHash TableLinked ListDesign
Solve → 18Parse Lisp ExpressionHardHash TableStringStack
Solve → 19Find Distance in a Binary TreeMediumHash TableTreeDepth-First Search
Solve → 20Design Task ManagerMediumHash TableDesignHeap (Priority Queue)
Solve → 21LRU CacheMediumHash TableLinked ListDesign
Solve → 22Longest Substring Without Repeating CharactersMediumHash TableStringSliding Window
Solve → 23Time Based Key-Value StoreMediumHash TableStringBinary Search
Solve → 24Word LadderHardHash TableStringBreadth-First Search
Solve → 25Implement Trie (Prefix Tree)MediumHash TableStringDesign
Solve → 26First Unique Character in a StringEasyHash TableStringQueue
Solve → 27Letter Combinations of a Phone NumberMediumHash TableStringBacktracking
Solve → 28Roman to IntegerEasyHash TableMathString
Solve → 29Valid AnagramEasyHash TableStringSorting
Solve → 30LFU CacheHardHash TableLinked ListDesign
Solve → 31Ransom NoteEasyHash TableStringCounting
Solve → 32Maximum Frequency StackHardHash TableStackDesign
Solve → 33Lowest Common Ancestor of a Binary Tree IIIMediumHash TableTwo PointersTree
Solve → 34Happy NumberEasyHash TableMathTwo Pointers
Solve → 35Find All Anagrams in a StringMediumHash TableStringSliding Window
Solve → 36Determine if Two Strings Are CloseMediumHash TableStringSorting
Solve → 37Intersection of Two Linked ListsEasyHash TableLinked ListTwo Pointers
Solve → 38Word Ladder IIHardHash TableStringBacktracking
Solve → 39Longest Substring with At Most K Distinct CharactersMediumHash TableStringSliding Window
Solve → 40Minimum Window SubstringHardHash TableStringSliding Window
Solve → 41Copy List with Random PointerMediumHash TableLinked List
Solve → 42Word Pattern IIMediumHash TableStringBacktracking
Solve → 43Clone GraphMediumHash TableDepth-First SearchBreadth-First Search
Solve → 44First Letter to Appear TwiceEasyHash TableStringBit Manipulation
Solve → 45Logger Rate LimiterEasyHash TableDesignData Stream
Solve → 46Design Log Storage SystemMediumHash TableStringDesign
Solve → 47Binary Tree Vertical Order TraversalMediumHash TableTreeDepth-First Search
Solve → 48LRU CacheMediumHash TableLinked ListDesign
Solve → 49Longest Substring Without Repeating CharactersMediumHash TableStringSliding Window
Solve → 50Time Based Key-Value StoreMediumHash TableStringBinary Search
Solve → 51Word LadderHardHash TableStringBreadth-First Search
Solve → 52Implement Trie (Prefix Tree)MediumHash TableStringDesign
Solve → 53Ransom NoteEasyHash TableStringCounting
Solve → 54First Unique Character in a StringEasyHash TableStringQueue
Solve → 55Letter Combinations of a Phone NumberMediumHash TableStringBacktracking
Solve → 56Roman to IntegerEasyHash TableMathString
Solve → 57Valid AnagramEasyHash TableStringSorting
Solve → 58LFU CacheHardHash TableLinked ListDesign
Solve → 59Lowest Common Ancestor of a Binary Tree IIIMediumHash TableTwo PointersTree
Solve → 60Maximum Frequency StackHardHash TableStackDesign
Solve → 61Happy NumberEasyHash TableMathTwo Pointers
Solve → 62Binary Tree Vertical Order TraversalMediumHash TableTreeDepth-First Search
Solve → 63Find All Anagrams in a StringMediumHash TableStringSliding Window
Solve → 64Design Log Storage SystemMediumHash TableStringDesign
Solve → 65Intersection of Two Linked ListsEasyHash TableLinked ListTwo Pointers
Solve → 66Determine if Two Strings Are CloseMediumHash TableStringSorting
Solve → 67Logger Rate LimiterEasyHash TableDesignData Stream
Solve → 68Word Ladder IIHardHash TableStringBacktracking
Solve → 69Longest Substring with At Most K Distinct CharactersMediumHash TableStringSliding Window
Solve → 70Minimum Window SubstringHardHash TableStringSliding Window
Solve → 71Copy List with Random PointerMediumHash TableLinked List
Solve → 72Design TwitterMediumHash TableLinked ListDesign
Solve → 73Longest Repeating Character ReplacementMediumHash TableStringSliding Window
Solve → 74First Letter to Appear TwiceEasyHash TableStringBit Manipulation
Solve → 75Word Pattern IIMediumHash TableStringBacktracking
Solve → 76Clone GraphMediumHash TableDepth-First SearchBreadth-First Search
Solve → 77Substring with Concatenation of All WordsHardHash TableStringSliding Window
Solve → 78Encode and Decode TinyURLMediumHash TableStringDesign
Solve → 79Permutation in StringMediumHash TableTwo PointersString
Solve → 80All Nodes Distance K in Binary TreeMediumHash TableTreeDepth-First Search
Solve → 81All O`one Data StructureHardHash TableLinked ListDesign
Solve → 82Parse Lisp ExpressionHardHash TableStringStack
Solve → 83Find Distance in a Binary TreeMediumHash TableTreeDepth-First Search
Solve → 84Design Task ManagerMediumHash TableDesignHeap (Priority Queue)
Solve →