1 Binary Tree Cameras Dynamic Programming Tree Depth-First Search Binary Tree
Hard 100
0.5% 2 Find Minimum Cost to Remove Array Elements Array Dynamic Programming
Medium 86
0.2% 3 Maximum Number of Subsequences After One Inserting String Dynamic Programming Greedy Prefix Sum
Medium 81
0.3% 4 Maximum Points After Collecting Coins From All Nodes Array Dynamic Programming Bit Manipulation Tree Depth-First Search Memoization
Hard 79
0.4% 5 Minimum Size Subarray in Infinite Array Array Hash Table Sliding Window Prefix Sum
Medium 79
0.3% 6 Maximum Subsequence Score Array Greedy Sorting Heap (Priority Queue)
Medium 79
0.5% 7 Minimum Number of Taps to Open to Water a Garden Array Dynamic Programming Greedy
Hard 77
0.5% 8 Relative Sort Array Array Hash Table Sorting Counting Sort
Easy 75
0.8% 9 Number of Subarrays With AND Value of K Array Binary Search Bit Manipulation Segment Tree
Hard 75
0.4% 10 Max Number of K-Sum Pairs Array Hash Table Two Pointers Sorting
Medium 75
0.6% 11 Sum Game Math String Greedy Game Theory
Medium 75
0.5% 12 Maximum Points Tourist Can Earn Array Dynamic Programming Matrix
Medium 75
0.5% 13 Letter Combinations of a Phone Number Hash Table String Backtracking
Medium 73
0.7% 14 Maximum Strength of K Disjoint Subarrays Array Dynamic Programming Prefix Sum
Hard 73
0.3% 15 Removing Minimum Number of Magic Beans Array Greedy Sorting Enumeration Prefix Sum
Medium 73
0.4% 16 Find the Sum of the Power of All Subsequences Array Dynamic Programming
Hard 73
0.4% 17 Minimum Cost Walk in Weighted Graph Array Bit Manipulation Union-Find Graph Theory
Hard 73
0.7% 18 Minimum Deletions to Make String K-Special Hash Table String Greedy Sorting Counting
Medium 73
0.7% 19 Greatest Sum Divisible by Three Array Dynamic Programming Greedy Sorting
Medium 73
0.6% 20 Query Kth Smallest Trimmed Number Array String Divide and Conquer Sorting Heap (Priority Queue) Radix Sort Quickselect
Medium 73
0.5% 21 Equal Row and Column Pairs Array Hash Table Matrix Simulation
Medium 73
0.7% 22 Number of Substrings Containing All Three Characters Hash Table String Sliding Window
Medium 73
0.7% 23 Maximum Deletions on a String String Dynamic Programming Rolling Hash String Matching Hash Function
Hard 73
0.4% 24 Median of a Row Wise Sorted Matrix Array Binary Search Matrix
Medium 73
0.7% 25 Determine the Winner of a Bowling Game Array Simulation
Easy 73
0.4% 26 Take Gifts From the Richest Pile Array Heap (Priority Queue) Simulation
Easy 73
0.8% 27 Find the Maximum Divisibility Score Array
Easy 73
0.5% 28 Shortest String That Contains Three Strings String Greedy Enumeration
Medium 73
0.3% 29 Find Peak Calling Hours for Each City Database
Medium 73
0.6% 30 Minimize Connected Groups by Inserting Interval Array Binary Search Sliding Window Sorting
Medium 73
0.5% 31 Minimum Runes to Add to Cast Spell Array Depth-First Search Breadth-First Search Graph Theory Topological Sort
Hard 73
0.4% 32 Count the Number of Incremovable Subarrays II Array Two Pointers Binary Search
Hard 71
0.4% 33 Trapping Rain Water Array Two Pointers Dynamic Programming Stack Monotonic Stack
Hard 62
0.7% 34 House Robber Array Dynamic Programming
Medium 58
0.5% 35 Insert Delete GetRandom O(1) Array Hash Table Math Design Randomized
Medium 58
0.6% 36 K-th Smallest in Lexicographical Order Trie
Hard 58
0.5% 37 Valid Parentheses String Stack
Easy 58
0.4% 38 Majority Element Array Hash Table Divide and Conquer Sorting Counting
Easy 58
0.7% 39 Minimum Number of Refueling Stops Array Dynamic Programming Greedy Heap (Priority Queue)
Hard 58
0.4% 40 Using a Robot to Print the Lexicographically Smallest String Hash Table String Stack Greedy
Medium 58
0.6% 41 Maximum Product Subarray Array Dynamic Programming
Medium 53
0.4% 42 Sliding Window Maximum Array Queue Sliding Window Heap (Priority Queue) Monotonic Queue
Hard 53
0.5% 43 Koko Eating Bananas Array Binary Search
Medium 53
0.5% 44 Kth Smallest Number in Multiplication Table Math Binary Search
Hard 53
0.5% 45 Longest String Chain Array Hash Table Two Pointers String Dynamic Programming Sorting
Medium 53
0.6% 46 Rotting Oranges Array Breadth-First Search Matrix
Medium 53
0.6% 47 Reorganize String Hash Table String Greedy Sorting Heap (Priority Queue) Counting
Medium 53
0.6% 48 Median of Two Sorted Arrays Array Binary Search Divide and Conquer
Hard 46
0.5% 49 Longest Consecutive Sequence Array Hash Table Union-Find
Medium 46
0.5% 50 Put Marbles in Bags Array Greedy Sorting Heap (Priority Queue)
Hard 46
0.7% 51 Average Waiting Time Array Simulation
Medium 46
0.7% 52 Open the Lock Array Hash Table String Breadth-First Search
Medium 46
0.6% 53 Minimum Number of Pushes to Type Word II Hash Table String Greedy Sorting Counting
Medium 46
0.8% 54 Find the Smallest Divisor Given a Threshold Array Binary Search
Medium 46
0.7% 55 Heaters Array Two Pointers Binary Search Sorting
Medium 46
0.4% 56 Shortest Subarray to be Removed to Make Array Sorted Array Two Pointers Binary Search Stack Monotonic Stack
Medium 46
0.5% 57 Consecutive Numbers Sum Math Enumeration
Hard 46
0.4% 58 Coin Change II Array Dynamic Programming
Medium 46
0.6% 59 K-th Symbol in Grammar Math Bit Manipulation Recursion
Medium 46
0.5% 60 Implement Rand10() Using Rand7() Math Rejection Sampling Randomized Probability and Statistics
Medium 46
0.5% 61 Excel Sheet Column Title Math String
Easy 46
0.5% 62 Maximize Score of Numbers in Ranges Array Binary Search Greedy Sorting
Medium 46
0.4% 63 Sum of Subarray Ranges Array Stack Monotonic Stack
Medium 46
0.6% 64 Asteroid Collision Array Stack Simulation
Medium 46
0.5% 65 Find Triangular Sum of an Array Array Math Simulation Combinatorics Number Theory
Medium 46
0.8% 66 Number of Islands Array Depth-First Search Breadth-First Search Union-Find Matrix
Medium 46
0.6% 67 LRU Cache Hash Table Linked List Design Doubly-Linked List
Medium 46
0.5% 68 Minimum Cost to Merge Stones Array Dynamic Programming Prefix Sum
Hard 46
0.5% 69 Furthest Building You Can Reach Array Greedy Heap (Priority Queue)
Medium 46
0.5% 70 Search a 2D Matrix Array Binary Search Matrix
Medium 46
0.5% 71 Unique Paths Math Dynamic Programming Combinatorics
Medium 37
0.7% 72 Best Time to Buy and Sell Stock Array Dynamic Programming
Easy 37
0.6% 73 Basic Calculator II Math String Stack
Medium 37
0.5% 74 Maximum Performance of a Team Array Greedy Sorting Heap (Priority Queue)
Hard 37
0.5% 75 Peak Index in a Mountain Array Array Binary Search
Medium 37
0.7% 76 Best Time to Buy and Sell Stock II Array Dynamic Programming Greedy
Medium 37
0.7% 77 Number of Ways to Reorder Array to Get Same BST Array Math Divide and Conquer Dynamic Programming Tree Union-Find Binary Search Tree Memoization Combinatorics Binary Tree
Hard 37
0.5% 78 Minimum Number of Visited Cells in a Grid Array Dynamic Programming Stack Breadth-First Search Union-Find Heap (Priority Queue) Matrix Monotonic Stack
Hard 37
0.2% 79 Maximum OR Array Greedy Bit Manipulation Prefix Sum
Medium 37
0.4% 80 Minimum Size Subarray Sum Array Binary Search Sliding Window Prefix Sum
Medium 37
0.5% 81 4Sum Array Two Pointers Sorting
Medium 37
0.4% 82 Maximum Points You Can Obtain from Cards Array Sliding Window Prefix Sum
Medium 37
0.6% 83 Find the Shortest Superstring Array String Dynamic Programming Bit Manipulation Bitmask
Hard 37
0.5% 84 Find First and Last Position of Element in Sorted Array Array Binary Search
Medium 37
0.5% 85 Split Array Largest Sum Array Binary Search Dynamic Programming Greedy Prefix Sum
Hard 37
0.6% 86 Flatten Nested List Iterator Stack Tree Depth-First Search Design Queue Iterator
Medium 37
0.7% 87 Design A Leaderboard Hash Table Design Sorting
Medium 37
0.7% 88 Decode Ways String Dynamic Programming
Medium 37
0.4% 89 Text Justification Array String Simulation
Hard 37
0.5% 90 Number of Ways to Wear Different Hats to Each Other Array Dynamic Programming Bit Manipulation Bitmask
Hard 37
0.5% 91 Word Search II Array String Backtracking Trie Matrix
Hard 37
0.4% 92 Longest Valid Parentheses String Dynamic Programming Stack
Hard 37
0.4% 93 Wildcard Matching String Dynamic Programming Greedy Recursion
Hard 37
0.3% 94 Longest Substring Without Repeating Characters Hash Table String Sliding Window
Medium 37
0.4% 95 Minimum Cost to Make at Least One Valid Path in a Grid Array Breadth-First Search Graph Theory Heap (Priority Queue) Matrix Shortest Path
Hard 37
0.7% 96 Number of Ways to Select Buildings String Dynamic Programming Prefix Sum
Medium 37
0.5% 97 Maximum Width Ramp Array Two Pointers Stack Monotonic Stack
Medium 37
0.6% 98 Loud and Rich Array Depth-First Search Graph Theory Topological Sort
Medium 37
0.6% 99 Count Binary Substrings Two Pointers String
Easy 37
0.7% 100 Two Sum Array Hash Table
Easy 37
0.6% 101 Merge Sorted Array Array Two Pointers Sorting
Easy 37
0.6% 102 Remove Duplicate Letters String Stack Greedy Monotonic Stack
Medium 37
0.5% 103 Next Permutation Array Two Pointers
Medium 37
0.5% 104 House Robber II Array Dynamic Programming
Medium 37
0.5% 105 Container With Most Water Array Two Pointers Greedy
Medium 37
0.6%