1 Friday Purchases I Database
Medium 100
0.8% 2 Two Sum Array Hash Table
Easy 87
0.6% 3 Longest Palindromic Substring Two Pointers String Dynamic Programming
Medium 77
0.4% 4 Palindrome Number Math
Easy 77
0.6% 5 Maximum Subarray Array Divide and Conquer Dynamic Programming
Medium 73
0.5% 6 Move Zeroes Array Two Pointers
Easy 72
0.6% 7 Majority Element Array Hash Table Divide and Conquer Sorting Counting
Easy 67
0.7% 8 Longest Common Prefix Array String Trie
Easy 66
0.5% 9 Best Time to Buy and Sell Stock Array Dynamic Programming
Easy 65
0.6% 10 Sort Colors Array Two Pointers Sorting
Medium 63
0.7% 11 Find the Index of the First Occurrence in a String Two Pointers String String Matching
Easy 62
0.5% 12 Valid Parentheses String Stack
Easy 62
0.4% 13 Single Number Array Bit Manipulation
Easy 62
0.8% 14 Second Highest Salary Database
Medium 62
0.5% 15 Valid Anagram Hash Table String Sorting
Easy 62
0.7% 16 Longest Substring Without Repeating Characters Hash Table String Sliding Window
Medium 61
0.4% 17 Subarray Sum Equals K Array Hash Table Prefix Sum
Medium 61
0.5% 18 Rotate Array Array Math Two Pointers
Medium 59
0.5% 19 Median of Two Sorted Arrays Array Binary Search Divide and Conquer
Hard 59
0.5% 20 Reverse Integer Math
Medium 57
0.3% 21 Container With Most Water Array Two Pointers Greedy
Medium 57
0.6% 22 3Sum Array Two Pointers Sorting
Medium 57
0.4% 23 Remove Duplicates from Sorted Array Array Two Pointers
Easy 57
0.6% 24 Jump Game Array Dynamic Programming Greedy
Medium 57
0.4% 25 Contains Duplicate Array Hash Table Sorting
Easy 57
0.6% 26 Remove Letter To Equalize Frequency Hash Table String Counting
Easy 57
0.2% 27 Count the Digits That Divide a Number Math
Easy 57
0.9% 28 Maximum Ascending Subarray Sum Array
Easy 57
0.7% 29 Maximum Product Subarray Array Dynamic Programming
Medium 56
0.4% 30 Reverse String Two Pointers String
Easy 56
0.8% 31 Minimum Cuts to Divide a Circle Math Geometry
Easy 56
0.6% 32 Minimum Operations to Exceed Threshold Value I Array
Easy 56
0.9% 33 Minimum Operations to Exceed Threshold Value II Array Heap (Priority Queue) Simulation
Medium 56
0.5% 34 Palindrome Partitioning IV String Dynamic Programming
Hard 56
0.5% 35 Check if Array Is Sorted and Rotated Array
Easy 56
0.6% 36 Valid Palindrome Two Pointers String
Easy 56
0.5% 37 Zigzag Grid Traversal With Skip Array Matrix Simulation
Easy 56
0.7% 38 Task Scheduler Array Hash Table Greedy Sorting Heap (Priority Queue) Counting
Medium 56
0.6% 39 Spiral Matrix Array Matrix Simulation
Medium 54
0.6% 40 Find First and Last Position of Element in Sorted Array Array Binary Search
Medium 51
0.5% 41 Trapping Rain Water Array Two Pointers Dynamic Programming Stack Monotonic Stack
Hard 51
0.7% 42 Pow(x, n) Math Recursion
Medium 51
0.4% 43 First Unique Character in a String Hash Table String Queue Counting
Easy 51
0.7% 44 Contains Duplicate II Array Hash Table Sliding Window
Easy 51
0.5% 45 Climbing Stairs Math Dynamic Programming Memoization
Easy 49
0.5% 46 Merge Sorted Array Array Two Pointers Sorting
Easy 49
0.6% 47 Toeplitz Matrix Array Matrix
Easy 49
0.7% 48 Bitwise ORs of Subarrays Array Dynamic Programming Bit Manipulation
Medium 49
0.6% 49 Fibonacci Number Math Dynamic Programming Recursion Memoization
Easy 49
0.7% 50 Merge Intervals Array Sorting
Medium 49
0.5% 51 Burst Balloons Array Dynamic Programming
Hard 49
0.6% 52 Search in Rotated Sorted Array Array Binary Search
Medium 49
0.5% 53 Roman to Integer Hash Table Math String
Easy 46
0.7% 54 Unique Paths Math Dynamic Programming Combinatorics
Medium 46
0.7% 55 Plus One Array Math
Easy 46
0.5% 56 Missing Number Array Hash Table Math Binary Search Bit Manipulation Sorting
Easy 46
0.7% 57 Add Binary Math String Bit Manipulation Simulation
Easy 46
0.6% 58 Single Element in a Sorted Array Array Binary Search
Medium 46
0.6% 59 Sort an Array Array Divide and Conquer Sorting Heap (Priority Queue) Merge Sort Bucket Sort Radix Sort Counting Sort
Medium 46
0.6% 60 Search Insert Position Array Binary Search
Easy 46
0.5% 61 N-Queens Array Backtracking
Hard 46
0.8% 62 Smallest Sufficient Team Array Dynamic Programming Bit Manipulation Bitmask
Hard 46
0.6% 63 Employees Earning More Than Their Managers Database
Easy 46
0.7% 64 Add Two Numbers Linked List Math Recursion
Medium 42
0.5% 65 4Sum Array Two Pointers Sorting
Medium 42
0.4% 66 Generate Parentheses String Dynamic Programming Backtracking
Medium 42
0.8% 67 Length of Last Word String
Easy 42
0.6% 68 Set Matrix Zeroes Array Hash Table Matrix
Medium 42
0.6% 69 Sqrt(x) Math Binary Search
Easy 42
0.4% 70 Pascal's Triangle Array Dynamic Programming
Easy 42
0.8% 71 Happy Number Hash Table Math Two Pointers
Easy 42
0.6% 72 Find the Duplicate Number Array Two Pointers Binary Search Bit Manipulation
Medium 42
0.6% 73 Split Array With Same Average Array Hash Table Math Dynamic Programming Bit Manipulation Bitmask
Hard 42
0.3% 74 Count Number of Pairs With Absolute Difference K Array Hash Table Counting
Easy 42
0.9% 75 Group Anagrams Array Hash Table String Sorting
Medium 42
0.7% 76 Remove Nth Node From End of List Linked List Two Pointers
Medium 42
0.5% 77 House Robber Array Dynamic Programming
Medium 42
0.5% 78 Min Stack Stack Design
Medium 42
0.6% 79 Middle of the Linked List Linked List Two Pointers
Easy 42
0.8% 80 Duplicate Emails Database
Easy 42
0.7% 81 Squares of a Sorted Array Array Two Pointers Sorting
Easy 42
0.7% 82 Next Permutation Array Two Pointers
Medium 38
0.5% 83 Reverse Words in a String Two Pointers String
Medium 38
0.6% 84 Sliding Window Maximum Array Queue Sliding Window Heap (Priority Queue) Monotonic Queue
Hard 38
0.5% 85 Diameter of Binary Tree Tree Depth-First Search Binary Tree
Easy 38
0.7% 86 Partition Equal Subset Sum Array Dynamic Programming
Medium 38
0.5% 87 Tallest Billboard Array Dynamic Programming
Hard 38
0.5% 88 Maximum Product of Three Numbers Array Math Sorting
Easy 38
0.5% 89 Serialize and Deserialize Binary Tree String Tree Depth-First Search Breadth-First Search Design Binary Tree
Hard 38
0.6% 90 Maximum Average Subarray I Array Sliding Window
Easy 38
0.5% 91 Search in Rotated Sorted Array II Array Binary Search
Medium 38
0.4% 92 Product Sales Analysis I Database
Easy 38
0.9% 93 Subsets II Array Backtracking Bit Manipulation
Medium 38
0.6% 94 Letter Combinations of a Phone Number Hash Table String Backtracking
Medium 38
0.7% 95 Find Minimum in Rotated Sorted Array Array Binary Search
Medium 38
0.5% 96 String to Integer (atoi) String
Medium 38
0.2% 97 Longest Palindromic Subsequence String Dynamic Programming
Medium 38
0.7% 98 Two Sum II - Input Array Is Sorted Array Two Pointers Binary Search
Medium 38
0.7% 99 Product of Array Except Self Array Prefix Sum
Medium 38
0.7% 100 Merge Two Sorted Lists Linked List Recursion
Easy 33
0.7% 101 Subsets Array Backtracking Bit Manipulation
Medium 33
0.8% 102 Best Time to Buy and Sell Stock II Array Dynamic Programming Greedy
Medium 33
0.7% 103 Largest Number Array String Greedy Sorting
Medium 33
0.4% 104 Department Top Three Salaries Database
Hard 33
0.6% 105 Count Primes Array Math Enumeration Number Theory
Medium 33
0.4% 106 Fizz Buzz Math String Simulation
Easy 33
0.8% 107 K-diff Pairs in an Array Array Hash Table Two Pointers Binary Search Sorting
Medium 33
0.5% 108 Find Customer Referee Database
Easy 33
0.7% 109 Peak Index in a Mountain Array Array Binary Search
Medium 33
0.7% 110 Article Views I Database
Easy 33
0.8% 111 Recyclable and Low Fat Products Database
Easy 33
0.9% 112 Maximal Rectangle Array Dynamic Programming Stack Matrix Monotonic Stack
Hard 33
0.6% 113 Max Consecutive Ones Array
Easy 33
0.7% 114 Project Employees I Database
Easy 33
0.7% 115 Number of Good Pairs Array Hash Table Math Counting
Easy 33
0.9% 116 Jump Game II Array Dynamic Programming Greedy
Medium 33
0.4% 117 Binary Tree Maximum Path Sum Dynamic Programming Tree Depth-First Search Binary Tree
Hard 33
0.4% 118 Merge k Sorted Lists Linked List Divide and Conquer Heap (Priority Queue) Merge Sort
Hard 33
0.6% 119 Ugly Number Math
Easy 33
0.4% 120 Koko Eating Bananas Array Binary Search
Medium 33
0.5% 121 Minimum Moves to Equal Array Elements II Array Math Sorting
Medium 33
0.6% 122 LRU Cache Hash Table Linked List Design Doubly-Linked List
Medium 33
0.5% 123 Delete the Middle Node of a Linked List Linked List Two Pointers
Medium 33
0.6% 124 Third Maximum Number Array Sorting
Easy 33
0.4% 125 First Missing Positive Array Hash Table
Hard 33
0.4% 126 Find Subsequence of Length K With the Largest Sum Array Hash Table Sorting Heap (Priority Queue)
Easy 33
0.6% 127 Longest Subarray of 1's After Deleting One Element Array Dynamic Programming Sliding Window
Medium 33
0.7% 128 Water Bottles Math Simulation
Easy 33
0.7% 129 Next Greater Element I Array Hash Table Stack Monotonic Stack
Easy 33
0.8% 130 Assign Cookies Array Two Pointers Greedy Sorting
Easy 33
0.6% 131 Remove Element Array Two Pointers
Easy 33
0.6% 132 Non-overlapping Intervals Array Dynamic Programming Greedy Sorting
Medium 33
0.6% 133 Range Sum Query - Immutable Array Design Prefix Sum
Easy 33
0.7% 134 Remove Duplicates from Sorted List Linked List
Easy 33
0.6% 135 Customer Who Visited but Did Not Make Any Transactions Database
Easy 33
0.7% 136 Longest Increasing Subsequence Array Binary Search Dynamic Programming
Medium 33
0.6% 137 String Compression Two Pointers String
Medium 33
0.6% 138 Maximum Total Subarray Value I Array Greedy
Medium 33
0.7% 139 Palindrome Linked List Linked List Two Pointers Stack Recursion
Easy 33
0.6% 140 Remove Duplicates from Sorted Array II Array Two Pointers
Medium 25
0.6% 141 Longest Consecutive Sequence Array Hash Table Union-Find
Medium 25
0.5% 142 Reverse Linked List Linked List Recursion
Easy 25
0.8% 143 Power of Two Math Bit Manipulation Recursion
Easy 25
0.5% 144 Employee Bonus Database
Easy 25
0.8% 145 Binary Search Array Binary Search
Easy 25
0.6% 146 Unique Paths II Array Dynamic Programming Matrix
Medium 25
0.4% 147 The kth Factor of n Math Number Theory
Medium 25
0.7% 148 Integer to English Words Math String Recursion
Hard 25
0.4% 149 Divisor Game Math Dynamic Programming Brainteaser Game Theory
Easy 25
0.7% 150 Maximum Swap Math Greedy
Medium 25
0.5% 151 Majority Element II Array Hash Table Sorting Counting
Medium 25
0.6% 152 String Compression III String
Medium 25
0.7% 153 Maximum Sum of Distinct Subarrays With Length K Array Hash Table Sliding Window
Medium 25
0.4% 154 Linked List Cycle Hash Table Linked List Two Pointers
Easy 25
0.5% 155 Running Sum of 1d Array Array Prefix Sum
Easy 25
0.9% 156 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 25
0.7% 157 Replace Employee ID With The Unique Identifier Database
Easy 25
0.8% 158 Permutation in String Hash Table Two Pointers String Sliding Window
Medium 25
0.5% 159 Check If Array Pairs Are Divisible by k Array Hash Table Counting
Medium 25
0.5% 160 Rotate Image Array Math Matrix
Medium 25
0.8% 161 Find K Closest Elements Array Two Pointers Binary Search Sliding Window Sorting Heap (Priority Queue)
Medium 25
0.5% 162 Count the Number of Fair Pairs Array Two Pointers Binary Search Sorting
Medium 25
0.5% 163 Return Length of Arguments Passed Easy 25
0.9% 164 Remove All Occurrences of a Substring String Stack Simulation
Medium 25
0.8% 165 Repeated Substring Pattern String String Matching
Easy 25
0.5% 166 Find the Original Typed String I String
Easy 25
0.7% 167 Maximum Gap Array Sorting Bucket Sort Radix Sort
Medium 25
0.5% 168 Maximum Number of Events That Can Be Attended II Array Binary Search Dynamic Programming Sorting
Hard 25
0.6% 169 Odd Even Linked List Linked List
Medium 25
0.6% 170 Convert Sorted List to Binary Search Tree Linked List Divide and Conquer Tree Binary Search Tree Binary Tree
Medium 25
0.7% 171 Subarray Product Less Than K Array Binary Search Sliding Window Prefix Sum
Medium 25
0.5% 172 Valid Word String
Easy 25
0.5% 173 Maximum Nesting Depth of the Parentheses String Stack
Easy 25
0.8% 174 Linked List Cycle II Hash Table Linked List Two Pointers
Medium 25
0.6% 175 Teemo Attacking Array Simulation
Easy 25
0.6% 176 Distribute Coins in Binary Tree Tree Depth-First Search Binary Tree
Medium 25
0.8% 177 Minimum Size Subarray Sum Array Binary Search Sliding Window Prefix Sum
Medium 25
0.5% 178 Binary Tree Inorder Traversal Stack Tree Depth-First Search Binary Tree
Easy 25
0.8% 179 Smallest Integer Divisible by K Hash Table Math
Medium 25
0.5% 180 Department Highest Salary Database
Medium 25
0.6% 181 How Many Numbers Are Smaller Than the Current Number Array Hash Table Sorting Counting Sort
Easy 25
0.9% 182 Reorder List Linked List Two Pointers Stack Recursion
Medium 25
0.7% 183 Bulb Switcher Math Brainteaser
Medium 25
0.6% 184 Regular Expression Matching String Dynamic Programming Recursion
Hard 25
0.3% 185 Managers with at Least 5 Direct Reports Database
Medium 25
0.5% 186 Intersection of Two Arrays II Array Hash Table Two Pointers Binary Search Sorting
Easy 25
0.6% 187 Rotting Oranges Array Breadth-First Search Matrix
Medium 25
0.6% 188 Longest Balanced Substring II Hash Table String Prefix Sum
Medium 25
0.4% 189 Count and Say String
Medium 25
0.6% 190 Integer to Roman Hash Table Math String
Medium 25
0.7% 191 Number of Islands Array Depth-First Search Breadth-First Search Union-Find Matrix
Medium 25
0.6% 192 Daily Temperatures Array Stack Monotonic Stack
Medium 25
0.7% 193 Convert a Number to Hexadecimal Math String Bit Manipulation
Easy 25
0.5% 194 Continuous Subarray Sum Array Hash Table Math Prefix Sum
Medium 25
0.3% 195 Longest Common Subsequence String Dynamic Programming
Medium 25
0.6% 196 Reshape the Matrix Array Matrix Simulation
Easy 25
0.7% 197 Permutations Array Backtracking
Medium 25
0.8% 198 Zigzag Conversion String
Medium 25
0.5% 199 Longest Palindrome Hash Table String Greedy
Easy 25
0.6% 200 Search a 2D Matrix Array Binary Search Matrix
Medium 25
0.5% 201 Find the Winner of the Circular Game Array Math Recursion Queue Simulation
Medium 25
0.8% 202 Intersection of Two Linked Lists Hash Table Linked List Two Pointers
Easy 25
0.6% 203 Word Ladder Hash Table String Breadth-First Search
Hard 25
0.5% 204 Remove Outermost Parentheses String Stack
Easy 25
0.9% 205 Min Cost Climbing Stairs Array Dynamic Programming
Easy 25
0.7% 206 Create Hello World Function Easy 25
0.8% 207 Rotate String String String Matching
Easy 25
0.7% 208 Swap Nodes in Pairs Linked List Recursion
Medium 25
0.7% 209 Find Smallest Letter Greater Than Target Array Binary Search
Easy 25
0.6% 210 Find Numbers with Even Number of Digits Array Math
Easy 25
0.8% 211 3Sum Closest Array Two Pointers Sorting
Medium 25
0.5% 212 Find Pivot Index Array Prefix Sum
Easy 25
0.6% 213 Top K Frequent Elements Array Hash Table Divide and Conquer Sorting Heap (Priority Queue) Bucket Sort Counting Quickselect
Medium 25
0.7% 214 Minimum Depth of Binary Tree Tree Depth-First Search Breadth-First Search Binary Tree
Easy 25
0.5% 215 Insert Interval Array
Medium 25
0.5% 216 Sort Array By Parity Array Two Pointers Sorting
Easy 25
0.8% 217 Subtract the Product and Sum of Digits of an Integer Math
Easy 25
0.9% 218 Delete Duplicate Emails Database
Easy 25
0.7% 219 Spiral Matrix II Array Matrix Simulation
Medium 25
0.8% 220 Multiply Strings Math String Simulation
Medium 25
0.4% 221 Same Tree Tree Depth-First Search Breadth-First Search Binary Tree
Easy 25
0.7% 222 Find All Numbers Disappeared in an Array Array Hash Table
Easy 25
0.6% 223 Contiguous Array Array Hash Table Prefix Sum
Medium 25
0.5% 224 Maximum Depth of Binary Tree Tree Depth-First Search Breadth-First Search Binary Tree
Easy 25
0.8% 225 Maximum Ice Cream Bars Array Greedy Sorting Counting Sort
Medium 25
0.8% 226 Binary Subarrays With Sum Array Hash Table Sliding Window Prefix Sum
Medium 25
0.7% 227 Consecutive Numbers Database
Medium 25
0.5% 228 Largest Rectangle in Histogram Array Stack Monotonic Stack
Hard 25
0.5%