1 LRU Cache Hash Table Linked List Design Doubly-Linked List
Medium 100
0.5% 2 Meeting Rooms II Array Two Pointers Greedy Sorting Heap (Priority Queue) Prefix Sum
Medium 96
0.5% 3 Number of Islands Array Depth-First Search Breadth-First Search Union-Find Matrix
Medium 94
0.6% 4 Minimum Window Substring Hash Table String Sliding Window
Hard 93
0.5% 5 Word Ladder Hash Table String Breadth-First Search
Hard 93
0.5% 6 Design Log Storage System Hash Table String Design Ordered Set
Medium 91
0.6% 7 Making A Large Island Array Depth-First Search Breadth-First Search Union-Find Matrix
Hard 89
0.6% 8 Number of Distinct Islands Array Hash Table Depth-First Search Breadth-First Search Union-Find Sorting Matrix Hash Function
Medium 89
0.6% 9 Word Break II Array Hash Table String Dynamic Programming Backtracking Trie Memoization
Hard 87
0.6% 10 Bus Routes Array Hash Table Breadth-First Search
Hard 87
0.5% 11 Combination Sum Array Backtracking
Medium 85
0.8% 12 Reverse Words in a String Two Pointers String
Medium 85
0.6% 13 Basic Calculator II Math String Stack
Medium 85
0.5% 14 Valid Sudoku Array Hash Table Matrix
Medium 83
0.6% 15 Sudoku Solver Array Hash Table Backtracking Matrix
Hard 83
0.7% 16 Combination Sum II Array Backtracking
Medium 83
0.6% 17 Wildcard Matching String Dynamic Programming Greedy Recursion
Hard 83
0.3% 18 Unique Binary Search Trees Math Dynamic Programming Tree Binary Search Tree Binary Tree
Medium 83
0.6% 19 Min Stack Stack Design
Medium 83
0.6% 20 One Edit Distance Two Pointers String
Medium 83
0.3% 21 Reverse Linked List Linked List Recursion
Easy 83
0.8% 22 Alien Dictionary Array String Depth-First Search Breadth-First Search Graph Theory Topological Sort
Hard 83
0.4% 23 Closest Binary Search Tree Value Binary Search Tree Depth-First Search Binary Search Tree Binary Tree
Easy 83
0.5% 24 Game of Life Array Matrix Simulation
Medium 83
0.7% 25 Burst Balloons Array Dynamic Programming
Hard 83
0.6% 26 Binary Tree Vertical Order Traversal Hash Table Tree Depth-First Search Breadth-First Search Sorting Binary Tree
Medium 83
0.6% 27 Combination Sum IV Array Dynamic Programming
Medium 83
0.6% 28 Remove K Digits String Stack Greedy Monotonic Stack
Medium 83
0.4% 29 Frog Jump Array Dynamic Programming
Hard 83
0.5% 30 Ternary Expression Parser String Stack Recursion
Medium 83
0.6% 31 String Compression Two Pointers String
Medium 83
0.6% 32 Word Abbreviation Array String Greedy Trie Sorting
Hard 83
0.6% 33 Largest Merge Of Two Strings Two Pointers String Greedy
Medium 83
0.5% 34 Least Operators to Express Number Math Dynamic Programming Memoization
Hard 83
0.5% 35 Bricks Falling When Hit Array Union-Find Matrix
Hard 83
0.4% 36 Course Schedule II Depth-First Search Breadth-First Search Graph Theory Topological Sort
Medium 77
0.6% 37 Top K Frequent Elements Array Hash Table Divide and Conquer Sorting Heap (Priority Queue) Bucket Sort Counting Quickselect
Medium 77
0.7% 38 Best Time to Buy and Sell Stock III Array Dynamic Programming
Hard 66
0.5% 39 Decode Ways String Dynamic Programming
Medium 66
0.4% 40 Best Meeting Point Array Math Sorting Matrix
Hard 66
0.6% 41 Evaluate Division Array String Depth-First Search Breadth-First Search Union-Find Graph Theory Shortest Path
Medium 60
0.6% 42 Basic Calculator III Math String Stack Recursion
Hard 60
0.5% 43 Count Unreachable Pairs of Nodes in an Undirected Graph Depth-First Search Breadth-First Search Union-Find Graph Theory
Medium 60
0.5% 44 Escape the Spreading Fire Array Binary Search Breadth-First Search Matrix
Hard 60
0.4% 45 Merge Intervals Array Sorting
Medium 53
0.5% 46 Course Schedule Depth-First Search Breadth-First Search Graph Theory Topological Sort
Medium 53
0.5% 47 Power of Two Math Bit Manipulation Recursion
Easy 53
0.5% 48 Minimum Remove to Make Valid Parentheses String Stack
Medium 53
0.7% 49 Shortest Path in a Grid with Obstacles Elimination Array Breadth-First Search Matrix
Hard 53
0.5% 50 Group Anagrams Array Hash Table String Sorting
Medium 53
0.7% 51 Minimum Area Rectangle Array Hash Table Math Geometry Sorting
Medium 53
0.6% 52 Reorder List Linked List Two Pointers Stack Recursion
Medium 53
0.7% 53 Word Search II Array String Backtracking Trie Matrix
Hard 53
0.4% 54 LFU Cache Hash Table Linked List Design Doubly-Linked List
Hard 53
0.5% 55 Reaching Points Math
Hard 53
0.3% 56 Basic Calculator Math String Stack Recursion
Hard 53
0.5% 57 Open the Lock Array Hash Table String Breadth-First Search
Medium 53
0.6% 58 Word Search Array String Backtracking Depth-First Search Matrix
Medium 43
0.5% 59 Binary Tree Maximum Path Sum Dynamic Programming Tree Depth-First Search Binary Tree
Hard 43
0.4% 60 Cheapest Flights Within K Stops Dynamic Programming Depth-First Search Breadth-First Search Graph Theory Heap (Priority Queue) Shortest Path
Medium 43
0.4% 61 Random Pick with Weight Array Math Binary Search Prefix Sum Randomized
Medium 43
0.5% 62 Design Browser History Array Linked List Stack Design Doubly-Linked List Data Stream
Medium 43
0.8% 63 K Closest Points to Origin Array Math Divide and Conquer Geometry Sorting Heap (Priority Queue) Quickselect
Medium 43
0.7% 64 The Maze Array Depth-First Search Breadth-First Search Matrix
Medium 43
0.6% 65 Product of Array Except Self Array Prefix Sum
Medium 43
0.7% 66 Search in Rotated Sorted Array Array Binary Search
Medium 43
0.5% 67 Shortest Path in Binary Matrix Array Breadth-First Search Matrix
Medium 43
0.5% 68 Minimum Number of Pushes to Type Word I Math String Greedy
Easy 43
0.7% 69 Letter Combinations of a Phone Number Hash Table String Backtracking
Medium 43
0.7% 70 Snapshot Array Array Hash Table Binary Search Design
Medium 43
0.4% 71 Add Binary Math String Bit Manipulation Simulation
Easy 43
0.6% 72 Number of Ways to Form a Target String Given a Dictionary Array String Dynamic Programming
Hard 43
0.6% 73 Design Add and Search Words Data Structure String Depth-First Search Design Trie
Medium 43
0.5% 74 Longest Substring Without Repeating Characters Hash Table String Sliding Window
Medium 43
0.4% 75 Minimum Path Sum Array Dynamic Programming Matrix
Medium 43
0.7% 76 Number of Submatrices That Sum to Target Array Hash Table Matrix Prefix Sum
Hard 43
0.7% 77 UTF-8 Validation Array Bit Manipulation
Medium 43
0.5% 78 Koko Eating Bananas Array Binary Search
Medium 43
0.5% 79 Sliding Window Median Array Hash Table Sliding Window Heap (Priority Queue)
Hard 43
0.4% 80 Possible Bipartition Depth-First Search Breadth-First Search Union-Find Graph Theory
Medium 43
0.5% 81 Most Stones Removed with Same Row or Column Hash Table Depth-First Search Union-Find Graph Theory
Medium 43
0.6% 82 Fraction to Recurring Decimal Hash Table Math String
Medium 43
0.3% 83 Design Hit Counter Array Binary Search Design Queue Data Stream
Medium 43
0.7% 84 Merge k Sorted Lists Linked List Divide and Conquer Heap (Priority Queue) Merge Sort
Hard 43
0.6%