1 Longest Non-decreasing Subarray From Two Arrays Array Dynamic Programming
Medium 100
29.8% 2 Binary Tree Maximum Path Sum Dynamic Programming Tree Depth-First Search Binary Tree
Hard 99
41.2% 3 Delete and Earn Array Hash Table Dynamic Programming
Medium 93
56.7% 4 Minimum Knight Moves Breadth-First Search
Medium 93
41.3% 5 Palindromic Substrings Two Pointers String Dynamic Programming
Medium 87
71.7% 6 Sliding Window Maximum Array Queue Sliding Window Heap (Priority Queue) Monotonic Queue
Hard 85
47.6% 7 Count Palindromic Subsequences String Dynamic Programming
Hard 81
39.3% 8 Minimum Equal Sum of Two Arrays After Replacing Zeros Array Greedy
Medium 80
50.2% 9 LFU Cache Hash Table Linked List Design Doubly-Linked List
Hard 80
46.6% 10 Minimum Operations to Make Numbers Non-positive Array Binary Search
Hard 78
42.2% 11 Number of Good Binary Strings Dynamic Programming
Medium 76
52.5% 12 Maximum Total Damage With Spell Casting Array Hash Table Two Pointers Binary Search Dynamic Programming Sorting Counting
Medium 76
27.7% 13 Maximum Length of Repeated Subarray Array Binary Search Dynamic Programming Sliding Window Rolling Hash Hash Function
Medium 74
51.0% 14 LRU Cache Hash Table Linked List Design Doubly-Linked List
Medium 74
45.2% 15 Minimum Costs Using the Train Line Array Dynamic Programming
Hard 74
77.6% 16 Best Position for a Service Centre Array Math Geometry Randomized
Hard 74
34.9% 17 Evaluate Division Array String Depth-First Search Breadth-First Search Union Find Graph Shortest Path
Medium 72
63.1% 18 First Completely Painted Row or Column Array Hash Table Matrix
Medium 72
63.9% 19 Longest String Chain Array Hash Table Two Pointers String Dynamic Programming Sorting
Medium 70
62.0% 20 Merge Intervals Array Sorting
Medium 70
49.4% 21 Best Time to Buy and Sell Stock Array Dynamic Programming
Easy 67
55.3% 22 Serialize and Deserialize Binary Tree String Tree Depth-First Search Breadth-First Search Design Binary Tree
Hard 67
59.0% 23 Find the Duplicate Number Array Two Pointers Binary Search Bit Manipulation
Medium 67
62.8% 24 Evaluate Reverse Polish Notation Array Math Stack
Medium 65
55.0% 25 Insert Delete GetRandom O(1) Array Hash Table Math Design Randomized
Medium 65
55.0% 26 Sudoku Solver Array Hash Table Backtracking Matrix
Hard 61
63.9% 27 Length of Longest Subarray With at Most K Frequency Array Hash Table Sliding Window
Medium 61
55.8% 28 Parallel Courses III Array Dynamic Programming Graph Topological Sort
Hard 61
66.7% 29 Number of Islands Array Depth-First Search Breadth-First Search Union Find Matrix
Medium 61
62.3% 30 Couples Holding Hands Greedy Depth-First Search Breadth-First Search Union Find Graph
Hard 57
58.4% 31 Find Median from Data Stream Two Pointers Design Sorting Heap (Priority Queue) Data Stream
Hard 57
53.3% 32 Group Anagrams Array Hash Table String Sorting
Medium 57
70.9% 33 Validate Binary Search Tree Tree Depth-First Search Binary Search Tree Binary Tree
Medium 57
34.4% 34 Meeting Scheduler Array Two Pointers Sorting
Medium 57
55.2% 35 Employee Free Time Array Line Sweep Sorting Heap (Priority Queue)
Hard 57
72.6% 36 Merge k Sorted Lists Linked List Divide and Conquer Heap (Priority Queue) Merge Sort
Hard 57
56.8% 37 Permutations Array Backtracking
Medium 57
80.7% 38 Robot Room Cleaner Backtracking Interactive
Hard 57
77.5% 39 Binary Tree Zigzag Level Order Traversal Tree Breadth-First Search Binary Tree
Medium 52
61.7% 40 Design Search Autocomplete System String Depth-First Search Design Trie Sorting Heap (Priority Queue) Data Stream
Hard 52
49.4% 41 N-Queens Array Backtracking
Hard 52
72.8% 42 Fizz Buzz Math String Simulation
Easy 52
74.4% 43 Best Time to Buy and Sell Stock II Array Dynamic Programming Greedy
Medium 52
69.5% 44 Regular Expression Matching String Dynamic Programming Recursion
Hard 52
29.3% 45 Best Time to Buy and Sell Stock III Array Dynamic Programming
Hard 52
51.1% 46 Search Suggestions System Array String Binary Search Trie Sorting Heap (Priority Queue)
Medium 52
65.1% 47 Combination Sum Array Backtracking
Medium 52
74.7% 48 Design Circular Queue Array Linked List Design Queue
Medium 52
52.6% 49 Trapping Rain Water Array Two Pointers Dynamic Programming Stack Monotonic Stack
Hard 52
65.1% 50 Word Search Array String Backtracking Depth-First Search Matrix
Medium 46
45.3% 51 Design Excel Sum Formula Array Hash Table String Graph Design Topological Sort Matrix
Hard 46
42.6% 52 Climbing Stairs Math Dynamic Programming Memoization
Easy 46
53.5% 53 Letter Combinations of a Phone Number Hash Table String Backtracking
Medium 46
63.9% 54 Sqrt(x) Math Binary Search
Easy 46
40.4% 55 Implement Trie (Prefix Tree) Hash Table String Design Trie
Medium 46
67.9% 56 Moving Average from Data Stream Array Design Queue Data Stream
Easy 46
79.9% 57 Sort Items by Groups Respecting Dependencies Depth-First Search Breadth-First Search Graph Topological Sort
Hard 46
65.6% 58 Design Front Middle Back Queue Array Linked List Design Queue Data Stream
Medium 46
56.3% 59 Median of Two Sorted Arrays Array Binary Search Divide and Conquer
Hard 46
43.8% 60 Find Servers That Handled Most Number of Requests Array Greedy Heap (Priority Queue) Ordered Set
Hard 46
44.1% 61 Longest Increasing Path in a Matrix Array Dynamic Programming Depth-First Search Breadth-First Search Graph Topological Sort Memoization Matrix
Hard 46
55.3% 62 House Robber Array Dynamic Programming
Medium 46
52.3% 63 Maximal Square Array Dynamic Programming Matrix
Medium 46
48.8% 64 3Sum Array Two Pointers Sorting
Medium 46
37.1% 65 Perfect Squares Math Dynamic Programming Breadth-First Search
Medium 46
55.7% 66 Minimum Height Trees Depth-First Search Breadth-First Search Graph Topological Sort
Medium 46
42.0% 67 Alien Dictionary Array String Depth-First Search Breadth-First Search Graph Topological Sort
Hard 46
36.7% 68 Count Ways To Build Good Strings Dynamic Programming
Medium 46
59.2% 69 Transform to Chessboard Array Math Bit Manipulation Matrix
Hard 46
50.6% 70 Best Time to Buy and Sell Stock with Transaction Fee Array Dynamic Programming Greedy
Medium 37
70.5% 71 Open the Lock Array Hash Table String Breadth-First Search
Medium 37
60.7% 72 Koko Eating Bananas Array Binary Search
Medium 37
49.1% 73 Populating Next Right Pointers in Each Node II Linked List Tree Depth-First Search Breadth-First Search Binary Tree
Medium 37
55.6% 74 Max Points on a Line Array Hash Table Math Geometry
Hard 37
29.0% 75 Integer to Roman Hash Table Math String
Medium 37
68.6% 76 Permutations II Array Backtracking Sorting
Medium 37
61.6% 77 Pow(x, n) Math Recursion
Medium 37
37.0% 78 Simplify Path String Stack
Medium 37
47.9% 79 Container With Most Water Array Two Pointers Greedy
Medium 37
57.8% 80 Rotting Oranges Array Breadth-First Search Matrix
Medium 37
56.6% 81 Longest Increasing Subsequence Array Binary Search Dynamic Programming
Medium 37
57.8% 82 Rank Transform of a Matrix Array Union Find Graph Topological Sort Sorting Matrix
Hard 37
41.4% 83 Paint House Array Dynamic Programming
Medium 37
63.7% 84 Subarray Sums Divisible by K Array Hash Table Prefix Sum
Medium 37
55.6% 85 Search a 2D Matrix II Array Binary Search Divide and Conquer Matrix
Medium 37
55.2% 86 Best Time to Buy and Sell Stock IV Array Dynamic Programming
Hard 37
47.1% 87 Insert Delete GetRandom O(1) - Duplicates allowed Array Hash Table Math Design Randomized
Hard 37
35.8% 88 Word Ladder II Hash Table String Backtracking Breadth-First Search
Hard 37
27.2% 89 Bus Routes Array Hash Table Breadth-First Search
Hard 37
47.0% 90 Course Schedule Depth-First Search Breadth-First Search Graph Topological Sort
Medium 37
49.2% 91 Reorganize String Hash Table String Greedy Sorting Heap (Priority Queue) Counting
Medium 37
56.2% 92 Longest Common Subsequence String Dynamic Programming
Medium 37
58.2% 93 Egg Drop With 2 Eggs and N Floors Math Dynamic Programming
Medium 37
73.7% 94 Course Schedule II Depth-First Search Breadth-First Search Graph Topological Sort
Medium 37
53.4% 95 Populating Next Right Pointers in Each Node Linked List Tree Depth-First Search Breadth-First Search Binary Tree
Medium 37
65.4% 96 Knight Probability in Chessboard Dynamic Programming
Medium 37
56.6% 97 Asteroid Collision Array Stack Simulation
Medium 37
45.5% 98 The Skyline Problem Array Divide and Conquer Binary Indexed Tree Segment Tree Line Sweep Heap (Priority Queue) Ordered Set
Hard 37
44.0% 99 Basic Calculator Math String Stack Recursion
Hard 37
45.6% 100 Count Number of Maximum Bitwise-OR Subsets Array Backtracking Bit Manipulation Enumeration
Medium 37
87.9%