1 Special Binary String String Divide and Conquer Sorting
Hard 100
0.8% 2 LRU Cache Hash Table Linked List Design Doubly-Linked List
Medium 88
0.5% 3 Longest Substring Without Repeating Characters Hash Table String Sliding Window
Medium 85
0.4% 4 Best Time to Buy and Sell Stock Array Dynamic Programming
Easy 82
0.6% 5 Two Sum Array Hash Table
Easy 81
0.6% 6 Merge k Sorted Lists Linked List Divide and Conquer Heap (Priority Queue) Merge Sort
Hard 79
0.6% 7 Valid Parentheses String Stack
Easy 77
0.4% 8 Group Anagrams Array Hash Table String Sorting
Medium 77
0.7% 9 Minimum Operations to Reduce an Integer to 0 Dynamic Programming Greedy Bit Manipulation
Medium 77
0.6% 10 Maximum Subarray Array Divide and Conquer Dynamic Programming
Medium 75
0.5% 11 Last Stone Weight Array Heap (Priority Queue)
Easy 75
0.7% 12 Maximize Greatness of an Array Array Two Pointers Greedy Sorting
Medium 75
0.6% 13 Number of Islands Array Depth-First Search Breadth-First Search Union-Find Matrix
Medium 73
0.6% 14 Maximum Number of Visible Points Array Math Geometry Sliding Window Sorting
Hard 73
0.4% 15 Search in Rotated Sorted Array Array Binary Search
Medium 71
0.5% 16 Fizz Buzz Math String Simulation
Easy 71
0.8% 17 Restore IP Addresses String Backtracking
Medium 71
0.6% 18 Trapping Rain Water Array Two Pointers Dynamic Programming Stack Monotonic Stack
Hard 68
0.7% 19 Reverse Bits Divide and Conquer Bit Manipulation
Easy 68
0.7% 20 Missing Number Array Hash Table Math Binary Search Bit Manipulation Sorting
Easy 65
0.7% 21 Dot Product of Two Sparse Vectors Array Hash Table Two Pointers Design
Medium 65
0.9% 22 Task Scheduler II Array Hash Table Simulation
Medium 65
0.5% 23 Merge Intervals Array Sorting
Medium 61
0.5% 24 Move Zeroes Array Two Pointers
Easy 61
0.6% 25 Find the Duplicate Number Array Two Pointers Binary Search Bit Manipulation
Medium 61
0.6% 26 Reverse Words in a String Two Pointers String
Medium 61
0.6% 27 4Sum Array Two Pointers Sorting
Medium 61
0.4% 28 Rotate List Linked List Two Pointers
Medium 61
0.4% 29 Container With Most Water Array Two Pointers Greedy
Medium 61
0.6% 30 Find The Original Array of Prefix Xor Array Bit Manipulation
Medium 61
0.9% 31 Add Two Numbers Linked List Math Recursion
Medium 57
0.5% 32 Fibonacci Number Math Dynamic Programming Recursion Memoization
Easy 57
0.7% 33 Insert Delete GetRandom O(1) Array Hash Table Math Design Randomized
Medium 57
0.6% 34 Reverse Linked List Linked List Recursion
Easy 57
0.8% 35 Merge Sorted Array Array Two Pointers Sorting
Easy 57
0.6% 36 Unique Paths II Array Dynamic Programming Matrix
Medium 57
0.4% 37 Max Sum of a Pair With Equal Sum of Digits Array Hash Table Sorting Heap (Priority Queue)
Medium 57
0.7% 38 Top K Frequent Elements Array Hash Table Divide and Conquer Sorting Heap (Priority Queue) Bucket Sort Counting Quickselect
Medium 57
0.7% 39 Sliding Window Maximum Array Queue Sliding Window Heap (Priority Queue) Monotonic Queue
Hard 57
0.5% 40 Rotate Image Array Math Matrix
Medium 52
0.8% 41 Copy List with Random Pointer Hash Table Linked List
Medium 52
0.6% 42 House Robber Array Dynamic Programming
Medium 52
0.5% 43 Break a Palindrome String Greedy
Medium 52
0.5% 44 String to Integer (atoi) String
Medium 52
0.2% 45 Rectangle Area Math Geometry
Medium 52
0.5% 46 Serialize and Deserialize Binary Tree String Tree Depth-First Search Breadth-First Search Design Binary Tree
Hard 52
0.6% 47 Remove Stones to Minimize the Total Array Greedy Heap (Priority Queue)
Medium 52
0.7% 48 String Compression Two Pointers String
Medium 52
0.6% 49 Asteroid Collision Array Stack Simulation
Medium 52
0.5% 50 Jump Game Array Dynamic Programming Greedy
Medium 52
0.4% 51 Power of Two Math Bit Manipulation Recursion
Easy 52
0.5% 52 Subarray Sum Equals K Array Hash Table Prefix Sum
Medium 52
0.5% 53 Valid Anagram Hash Table String Sorting
Easy 52
0.7% 54 Product of Array Except Self Array Prefix Sum
Medium 52
0.7% 55 Maximum Number of Events That Can Be Attended Array Greedy Sorting Heap (Priority Queue)
Medium 52
0.4% 56 Minimum Absolute Difference Array Sorting
Easy 52
0.8% 57 3Sum Array Two Pointers Sorting
Medium 46
0.4% 58 Generate Parentheses String Dynamic Programming Backtracking
Medium 46
0.8% 59 Climbing Stairs Math Dynamic Programming Memoization
Easy 46
0.5% 60 Set Matrix Zeroes Array Hash Table Matrix
Medium 46
0.6% 61 Reverse Linked List II Linked List
Medium 46
0.5% 62 Find Peak Element Array Binary Search
Medium 46
0.5% 63 Maximal Square Array Dynamic Programming Matrix
Medium 46
0.5% 64 Find Median from Data Stream Two Pointers Design Sorting Heap (Priority Queue) Data Stream
Hard 46
0.5% 65 Counting Bits Dynamic Programming Bit Manipulation
Easy 46
0.8% 66 Maximum Sum of Distinct Subarrays With Length K Array Hash Table Sliding Window
Medium 46
0.4% 67 Spiral Matrix Array Matrix Simulation
Medium 46
0.6% 68 Remove Duplicates from Sorted List Linked List
Easy 46
0.6% 69 Course Schedule II Depth-First Search Breadth-First Search Graph Theory Topological Sort
Medium 46
0.6% 70 Count the Number of Good Subsequences Hash Table Math String Combinatorics Counting
Medium 46
0.5% 71 Sort Colors Array Two Pointers Sorting
Medium 46
0.7% 72 Minimum Path Sum Array Dynamic Programming Matrix
Medium 46
0.7% 73 Linked List Cycle Hash Table Linked List Two Pointers
Easy 46
0.5% 74 First Unique Character in a String Hash Table String Queue Counting
Easy 46
0.7% 75 Rotting Oranges Array Breadth-First Search Matrix
Medium 46
0.6% 76 Find the Celebrity Two Pointers Graph Theory Interactive
Medium 46
0.5% 77 Course Schedule Depth-First Search Breadth-First Search Graph Theory Topological Sort
Medium 46
0.5% 78 Longest Increasing Subsequence Array Binary Search Dynamic Programming
Medium 46
0.6% 79 Min Stack Stack Design
Medium 46
0.6% 80 Longest Consecutive Sequence Array Hash Table Union-Find
Medium 46
0.5% 81 Palindrome Linked List Linked List Two Pointers Stack Recursion
Easy 46
0.6% 82 Minimum Knight Moves Breadth-First Search
Medium 37
0.4% 83 Max Points on a Line Array Hash Table Math Geometry
Hard 37
0.3% 84 Kth Largest Element in an Array Array Divide and Conquer Sorting Heap (Priority Queue) Quickselect
Medium 37
0.7% 85 H-Index Array Sorting Counting Sort
Medium 37
0.4% 86 Linked List Random Node Linked List Math Reservoir Sampling Randomized
Medium 37
0.6% 87 Sliding Puzzle Array Dynamic Programming Backtracking Breadth-First Search Memoization Matrix
Hard 37
0.7% 88 All Possible Full Binary Trees Dynamic Programming Tree Recursion Memoization Binary Tree
Medium 37
0.8% 89 Longest Common Prefix Array String Trie
Easy 37
0.5% 90 Minimum Size Subarray Sum Array Binary Search Sliding Window Prefix Sum
Medium 37
0.5% 91 Delete Duplicate Folders in System Array Hash Table String Depth-First Search Trie Sorting Hash Function
Hard 37
0.8% 92 Reverse String Two Pointers String
Easy 37
0.8% 93 Number of 1 Bits Divide and Conquer Bit Manipulation
Easy 37
0.8% 94 Merge In Between Linked Lists Linked List
Medium 37
0.8% 95 The Maze Array Depth-First Search Breadth-First Search Matrix
Medium 37
0.6% 96 Integer to English Words Math String Recursion
Hard 37
0.4% 97 Task Scheduler Array Hash Table Greedy Sorting Heap (Priority Queue) Counting
Medium 37
0.6% 98 Remove Duplicates from Sorted List II Linked List Two Pointers
Medium 37
0.5% 99 Largest Number Array String Greedy Sorting
Medium 37
0.4% 100 Clone Graph Hash Table Depth-First Search Breadth-First Search Graph Theory
Medium 37
0.7% 101 Daily Temperatures Array Stack Monotonic Stack
Medium 37
0.7% 102 Middle of the Linked List Linked List Two Pointers
Easy 37
0.8% 103 Merge Two Sorted Lists Linked List Recursion
Easy 37
0.7% 104 Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit Array Queue Sliding Window Heap (Priority Queue) Ordered Set Monotonic Queue
Medium 37
0.6% 105 Number of Ways to Split Array Array Prefix Sum
Medium 37
0.6% 106 Pow(x, n) Math Recursion
Medium 37
0.4% 107 Maximum Product of Three Numbers Array Math Sorting
Easy 37
0.5% 108 Sqrt(x) Math Binary Search
Easy 37
0.4% 109 Unique Paths Math Dynamic Programming Combinatorics
Medium 37
0.7% 110 Simplify Path String Stack
Medium 37
0.5% 111 Word Pattern Hash Table String
Easy 37
0.4% 112 The Skyline Problem Array Divide and Conquer Binary Indexed Tree Segment Tree Sweep Line Sorting Heap (Priority Queue) Ordered Set
Hard 37
0.5% 113 Find K Closest Elements Array Two Pointers Binary Search Sliding Window Sorting Heap (Priority Queue)
Medium 37
0.5% 114 Third Maximum Number Array Sorting
Easy 37
0.4% 115 Decode String String Stack Recursion
Medium 37
0.6% 116 Median of Two Sorted Arrays Array Binary Search Divide and Conquer
Hard 37
0.5% 117 Number of Lines To Write String Array String
Easy 37
0.7% 118 Shuffle an Array Array Math Design Randomized
Medium 37
0.6% 119 Longest Palindromic Substring Two Pointers String Dynamic Programming
Medium 37
0.4% 120 Next Greater Element II Array Stack Monotonic Stack
Medium 37
0.7% 121 Diameter of Binary Tree Tree Depth-First Search Binary Tree
Easy 37
0.7% 122 Compare Version Numbers Two Pointers String
Medium 37
0.5% 123 Maximum Product Subarray Array Dynamic Programming
Medium 37
0.4% 124 Number of Visible People in a Queue Array Stack Monotonic Stack
Hard 37
0.7% 125 Count Primes Array Math Enumeration Number Theory
Medium 37
0.4% 126 All Nodes Distance K in Binary Tree Hash Table Tree Depth-First Search Breadth-First Search Binary Tree
Medium 37
0.7% 127 Add Two Numbers II Linked List Math Stack
Medium 37
0.6% 128 Contains Duplicate Array Hash Table Sorting
Easy 37
0.6% 129 Design Memory Allocator Array Hash Table Design Simulation
Medium 37
0.5% 130 Fizz Buzz Multithreaded Concurrency
Medium 37
0.7% 131 Longest Cycle in a Graph Depth-First Search Breadth-First Search Graph Theory Topological Sort
Hard 37
0.5% 132 Network Delay Time Depth-First Search Breadth-First Search Graph Theory Heap (Priority Queue) Shortest Path
Medium 37
0.6% 133 Design Circular Queue Array Linked List Design Queue
Medium 37
0.5% 134 Binary Subarrays With Sum Array Hash Table Sliding Window Prefix Sum
Medium 37
0.7% 135 Previous Permutation With One Swap Array Greedy
Medium 37
0.5% 136 Koko Eating Bananas Array Binary Search
Medium 37
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