1 LRU Cache Hash Table Linked List Design Doubly-Linked List
Medium 100
0.5% 2 Longest Substring Without Repeating Characters Hash Table String Sliding Window
Medium 87
0.4% 3 Number of Islands Array Depth-First Search Breadth-First Search Union-Find Matrix
Medium 83
0.6% 4 Two Sum Array Hash Table
Easy 83
0.6% 5 Group Anagrams Array Hash Table String Sorting
Medium 81
0.7% 6 Top K Frequent Elements Array Hash Table Divide and Conquer Sorting Heap (Priority Queue) Bucket Sort Counting Quickselect
Medium 77
0.7% 7 Sliding Window Maximum Array Queue Sliding Window Heap (Priority Queue) Monotonic Queue
Hard 76
0.5% 8 Merge k Sorted Lists Linked List Divide and Conquer Heap (Priority Queue) Merge Sort
Hard 73
0.6% 9 Valid Parentheses String Stack
Easy 73
0.4% 10 Merge Intervals Array Sorting
Medium 70
0.5% 11 Longest Palindromic Substring Two Pointers String Dynamic Programming
Medium 69
0.4% 12 Spiral Matrix Array Matrix Simulation
Medium 69
0.6% 13 Meeting Rooms II Array Two Pointers Greedy Sorting Heap (Priority Queue) Prefix Sum
Medium 69
0.5% 14 Minimum One Bit Operations to Make Integers Zero Math Dynamic Programming Bit Manipulation Recursion Memoization
Hard 68
0.8% 15 Search in Rotated Sorted Array Array Binary Search
Medium 66
0.5% 16 LFU Cache Hash Table Linked List Design Doubly-Linked List
Hard 66
0.5% 17 Asteroid Collision Array Stack Simulation
Medium 65
0.5% 18 Container With Most Water Array Two Pointers Greedy
Medium 63
0.6% 19 3Sum Array Two Pointers Sorting
Medium 63
0.4% 20 Reverse Linked List Linked List Recursion
Easy 63
0.8% 21 Remove All Adjacent Duplicates in String II String Stack
Medium 63
0.6% 22 Trapping Rain Water Array Two Pointers Dynamic Programming Stack Monotonic Stack
Hard 62
0.7% 23 Longest Consecutive Sequence Array Hash Table Union-Find
Medium 62
0.5% 24 Min Stack Stack Design
Medium 62
0.6% 25 Minimum Absolute Difference Array Sorting
Easy 62
0.8% 26 Roman to Integer Hash Table Math String
Easy 60
0.7% 27 Maximum Subarray Array Divide and Conquer Dynamic Programming
Medium 60
0.5% 28 Valid Anagram Hash Table String Sorting
Easy 60
0.7% 29 Count Pairs Of Similar Strings Array Hash Table String Bit Manipulation Counting
Easy 60
0.7% 30 Maximize Value of Function in a Ball Passing Game Array Dynamic Programming Bit Manipulation
Hard 60
0.3% 31 Rotting Oranges Array Breadth-First Search Matrix
Medium 60
0.6% 32 Find Valid Pair of Adjacent Digits in String Hash Table String Counting
Easy 60
0.6% 33 Generate Parentheses String Dynamic Programming Backtracking
Medium 58
0.8% 34 Best Time to Buy and Sell Stock Array Dynamic Programming
Easy 58
0.6% 35 Binary Tree Right Side View Tree Depth-First Search Breadth-First Search Binary Tree
Medium 58
0.7% 36 Lowest Common Ancestor of a Binary Tree Tree Depth-First Search Binary Tree
Medium 58
0.7% 37 Decode String String Stack Recursion
Medium 58
0.6% 38 Count Ways To Build Good Strings Dynamic Programming
Medium 58
0.6% 39 Count Ways to Group Overlapping Ranges Array Sorting
Medium 58
0.4% 40 Count Distinct Numbers on Board Array Hash Table Math Simulation
Easy 58
0.6% 41 Minimize Length of Array Using Operations Array Math Greedy Number Theory
Medium 58
0.4% 42 Count the Number of Houses at a Certain Distance I Breadth-First Search Graph Theory Prefix Sum
Medium 58
0.6% 43 Count the Number of Houses at a Certain Distance II Graph Theory Prefix Sum
Hard 58
0.2% 44 All Ancestors of a Node in a Directed Acyclic Graph Depth-First Search Breadth-First Search Graph Theory Topological Sort
Medium 58
0.6% 45 Lucky Numbers in a Matrix Array Matrix
Easy 58
0.8% 46 HTML Entity Parser Hash Table String
Medium 58
0.5% 47 Design Authentication Manager Hash Table Linked List Design Doubly-Linked List
Medium 58
0.6% 48 Koko Eating Bananas Array Binary Search
Medium 58
0.5% 49 Median of Two Sorted Arrays Array Binary Search Divide and Conquer
Hard 56
0.5% 50 Longest Common Prefix Array String Trie
Easy 56
0.5% 51 Sort Colors Array Two Pointers Sorting
Medium 56
0.7% 52 Binary Tree Zigzag Level Order Traversal Tree Breadth-First Search Binary Tree
Medium 56
0.6% 53 Course Schedule Depth-First Search Breadth-First Search Graph Theory Topological Sort
Medium 56
0.5% 54 Find Median from Data Stream Two Pointers Design Sorting Heap (Priority Queue) Data Stream
Hard 56
0.5% 55 Maximum Number of Events That Can Be Attended Array Greedy Sorting Heap (Priority Queue)
Medium 56
0.4% 56 Word Squares II Array String Backtracking Sorting Enumeration
Medium 56
0.6% 57 Zigzag Conversion String
Medium 53
0.5% 58 First Missing Positive Array Hash Table
Hard 53
0.4% 59 Restore IP Addresses String Backtracking
Medium 53
0.6% 60 Kth Largest Element in an Array Array Divide and Conquer Sorting Heap (Priority Queue) Quickselect
Medium 53
0.7% 61 Coin Change Array Dynamic Programming Breadth-First Search
Medium 53
0.5% 62 Delete Node in a BST Tree Binary Search Tree Binary Tree
Medium 53
0.5% 63 Contiguous Array Array Hash Table Prefix Sum
Medium 53
0.5% 64 Diameter of Binary Tree Tree Depth-First Search Binary Tree
Easy 53
0.7% 65 Unique Binary Search Trees Math Dynamic Programming Tree Binary Search Tree Binary Tree
Medium 53
0.6% 66 Simplify Path String Stack
Medium 53
0.5% 67 Implement Trie (Prefix Tree) Hash Table String Design Trie
Medium 53
0.7% 68 Binary Tree Maximum Path Sum Dynamic Programming Tree Depth-First Search Binary Tree
Hard 50
0.4% 69 Copy List with Random Pointer Hash Table Linked List
Medium 50
0.6% 70 Majority Element Array Hash Table Divide and Conquer Sorting Counting
Easy 50
0.7% 71 Kth Smallest Element in a BST Tree Depth-First Search Binary Search Tree Binary Tree
Medium 50
0.8% 72 Product of Array Except Self Array Prefix Sum
Medium 50
0.7% 73 Logger Rate Limiter Hash Table Design Data Stream
Easy 50
0.8% 74 Insert Delete GetRandom O(1) Array Hash Table Math Design Randomized
Medium 50
0.6% 75 Binary Tree Level Order Traversal Tree Breadth-First Search Binary Tree
Medium 50
0.7% 76 Task Scheduler Array Hash Table Greedy Sorting Heap (Priority Queue) Counting
Medium 50
0.6% 77 Degree of an Array Array Hash Table
Easy 50
0.6% 78 Time Based Key-Value Store Hash Table String Binary Search Design
Medium 50
0.5% 79 Vertical Order Traversal of a Binary Tree Hash Table Tree Depth-First Search Breadth-First Search Sorting Binary Tree
Hard 50
0.5% 80 Word Ladder Hash Table String Breadth-First Search
Hard 50
0.5% 81 Count the Number of Infection Sequences Array Math Combinatorics
Hard 50
0.4% 82 Integer to Roman Hash Table Math String
Medium 47
0.7% 83 Letter Combinations of a Phone Number Hash Table String Backtracking
Medium 47
0.7% 84 Find First and Last Position of Element in Sorted Array Array Binary Search
Medium 47
0.5% 85 Minimum Window Substring Hash Table String Sliding Window
Hard 47
0.5% 86 Validate Binary Search Tree Tree Depth-First Search Binary Search Tree Binary Tree
Medium 47
0.4% 87 Gas Station Array Greedy
Medium 47
0.5% 88 Word Break II Array Hash Table String Dynamic Programming Backtracking Trie Memoization
Hard 47
0.6% 89 Maximal Square Array Dynamic Programming Matrix
Medium 47
0.5% 90 Search a 2D Matrix II Array Binary Search Divide and Conquer Matrix
Medium 47
0.6% 91 Move Zeroes Array Two Pointers
Easy 47
0.6% 92 Longest Increasing Subsequence Array Binary Search Dynamic Programming
Medium 47
0.6% 93 Reverse Vowels of a String Two Pointers String
Easy 47
0.6% 94 Search a 2D Matrix Array Binary Search Matrix
Medium 47
0.5% 95 String Compression Two Pointers String
Medium 47
0.6% 96 Subarray Sum Equals K Array Hash Table Prefix Sum
Medium 47
0.5% 97 Design In-Memory File System Hash Table String Design Trie Sorting
Hard 47
0.5% 98 Maximum Profit From Trading Stocks Array Dynamic Programming
Medium 47
0.5% 99 Valid Palindrome Two Pointers String
Easy 47
0.5% 100 Palindromic Substrings Two Pointers String Dynamic Programming
Medium 47
0.7% 101 N-Queens Array Backtracking
Hard 47
0.8% 102 Merge In Between Linked Lists Linked List
Medium 47
0.8% 103 Pour Water Array Simulation
Medium 47
0.5% 104 Diagonal Traverse Array Matrix Simulation
Medium 47
0.7% 105 Longest Mountain in Array Array Two Pointers Dynamic Programming Enumeration
Medium 47
0.4% 106 Add Two Numbers Linked List Math Recursion
Medium 43
0.5% 107 Rotate Image Array Math Matrix
Medium 43
0.8% 108 Jump Game Array Dynamic Programming Greedy
Medium 43
0.4% 109 Set Matrix Zeroes Array Hash Table Matrix
Medium 43
0.6% 110 Word Search Array String Backtracking Depth-First Search Matrix
Medium 43
0.5% 111 Largest Number Array String Greedy Sorting
Medium 43
0.4% 112 Course Schedule II Depth-First Search Breadth-First Search Graph Theory Topological Sort
Medium 43
0.6% 113 Palindrome Number Math
Easy 43
0.6% 114 Meeting Rooms Array Sorting
Easy 43
0.6% 115 Single Element in a Sorted Array Array Binary Search
Medium 43
0.6% 116 Top K Frequent Words Array Hash Table String Trie Sorting Heap (Priority Queue) Bucket Sort Counting
Medium 43
0.6% 117 Number of Distinct Islands Array Hash Table Depth-First Search Breadth-First Search Union-Find Sorting Matrix Hash Function
Medium 43
0.6% 118 Reorganize String Hash Table String Greedy Sorting Heap (Priority Queue) Counting
Medium 43
0.6% 119 Design HashMap Array Hash Table Linked List Design Hash Function
Easy 43
0.7% 120 Pairs of Songs With Total Durations Divisible by 60 Array Hash Table Counting
Medium 43
0.5% 121 Maximum Profit in Job Scheduling Array Binary Search Dynamic Programming Sorting
Hard 43
0.5% 122 Search Suggestions System Array String Binary Search Trie Sorting Heap (Priority Queue)
Medium 43
0.7% 123 Max Area of Island Array Depth-First Search Breadth-First Search Union-Find Matrix
Medium 43
0.7% 124 Reverse Words in a String Two Pointers String
Medium 43
0.6% 125 Count Vowel Substrings of a String Hash Table String
Easy 43
0.7% 126 Next Permutation Array Two Pointers
Medium 43
0.5% 127 Number of Visible People in a Queue Array Stack Monotonic Stack
Hard 43
0.7% 128 Second Highest Salary Database
Medium 43
0.5% 129 Consecutive Numbers Sum Math Enumeration
Hard 43
0.4% 130 Merge Two Sorted Lists Linked List Recursion
Easy 39
0.7% 131 Remove Duplicates from Sorted Array Array Two Pointers
Easy 39
0.6% 132 Combination Sum II Array Backtracking
Medium 39
0.6% 133 Permutations Array Backtracking
Medium 39
0.8% 134 Rotate List Linked List Two Pointers
Medium 39
0.4% 135 Linked List Cycle Hash Table Linked List Two Pointers
Easy 39
0.5% 136 Delete Node in a Linked List Linked List
Medium 39
0.8% 137 Maximum Number of Non-overlapping Palindrome Substrings Two Pointers String Dynamic Programming Greedy
Hard 39
0.4% 138 Capacity To Ship Packages Within D Days Array Binary Search
Medium 39
0.7% 139 Kth Smallest Element in a Sorted Matrix Array Binary Search Sorting Heap (Priority Queue) Matrix
Medium 39
0.6% 140 Maximum Good People Based on Statements Array Backtracking Bit Manipulation Enumeration
Hard 39
0.5% 141 Sort an Array Array Divide and Conquer Sorting Heap (Priority Queue) Merge Sort Bucket Sort Radix Sort Counting Sort
Medium 39
0.6% 142 Kill Process Array Hash Table Tree Depth-First Search Breadth-First Search
Medium 39
0.7% 143 Find the Winner of the Circular Game Array Math Recursion Queue Simulation
Medium 39
0.8% 144 House Robber Array Dynamic Programming
Medium 39
0.5% 145 Permutation in String Hash Table Two Pointers String Sliding Window
Medium 39
0.5% 146 Find the Smallest Divisor Given a Threshold Array Binary Search
Medium 39
0.7% 147 Subarray Product Less Than K Array Binary Search Sliding Window Prefix Sum
Medium 39
0.5% 148 Reverse Integer Math
Medium 39
0.3% 149 Divide Two Integers Math Bit Manipulation
Medium 39
0.2% 150 Surrounded Regions Array Depth-First Search Breadth-First Search Union-Find Matrix
Medium 39
0.5% 151 Minimum Array Sum Array Dynamic Programming
Medium 39
0.3% 152 Find Leaves of Binary Tree Tree Depth-First Search Binary Tree
Medium 39
0.8% 153 Regular Expression Matching String Dynamic Programming Recursion
Hard 33
0.3% 154 Pow(x, n) Math Recursion
Medium 33
0.4% 155 Remove Duplicates from Sorted List Linked List
Easy 33
0.6% 156 Merge Sorted Array Array Two Pointers Sorting
Easy 33
0.6% 157 Populating Next Right Pointers in Each Node Linked List Tree Depth-First Search Breadth-First Search Binary Tree
Medium 33
0.7% 158 Sort List Linked List Two Pointers Divide and Conquer Sorting Merge Sort
Medium 33
0.6% 159 Two Sum II - Input Array Is Sorted Array Two Pointers Binary Search
Medium 33
0.7% 160 Isomorphic Strings Hash Table String
Easy 33
0.5% 161 Minimum Size Subarray Sum Array Binary Search Sliding Window Prefix Sum
Medium 33
0.5% 162 Basic Calculator Math String Stack Recursion
Hard 33
0.5% 163 Palindrome Linked List Linked List Two Pointers Stack Recursion
Easy 33
0.6% 164 Integer to English Words Math String Recursion
Hard 33
0.4% 165 Sqrt(x) Math Binary Search
Easy 33
0.4% 166 Find K Pairs with Smallest Sums Array Heap (Priority Queue)
Medium 33
0.4% 167 First Unique Character in a String Hash Table String Queue Counting
Easy 33
0.7% 168 Add Strings Math String Simulation
Easy 33
0.5% 169 Island Perimeter Array Depth-First Search Breadth-First Search Matrix
Easy 33
0.7% 170 Rearranging Fruits Array Hash Table Greedy Sort
Hard 33
0.6% 171 Count Binary Substrings Two Pointers String
Easy 33
0.7% 172 Word Break Array Hash Table String Dynamic Programming Trie Memoization
Medium 33
0.5% 173 Daily Temperatures Array Stack Monotonic Stack
Medium 33
0.7% 174 Remove All Adjacent Duplicates In String String Stack
Easy 33
0.7% 175 Distinct Subsequences String Dynamic Programming
Hard 33
0.5% 176 Non-overlapping Intervals Array Dynamic Programming Greedy Sorting
Medium 33
0.6% 177 Flatten Binary Tree to Linked List Linked List Stack Tree Depth-First Search Binary Tree
Medium 33
0.7% 178 Contains Duplicate Array Hash Table Sorting
Easy 33
0.6% 179 Reformat Date String
Easy 33
0.7% 180 Next Greater Element I Array Hash Table Stack Monotonic Stack
Easy 33
0.8% 181 Find Minimum in Rotated Sorted Array Array Binary Search
Medium 33
0.5% 182 Basic Calculator II Math String Stack
Medium 33
0.5% 183 Longest Substring with At Most K Distinct Characters Hash Table String Sliding Window
Medium 33
0.5% 184 Calculate Amount Paid in Taxes Array Simulation
Easy 33
0.7% 185 Convert Binary Number in a Linked List to Integer Linked List Math
Easy 33
0.8% 186 All Nodes Distance K in Binary Tree Hash Table Tree Depth-First Search Breadth-First Search Binary Tree
Medium 33
0.7% 187 Triangle Array Dynamic Programming
Medium 33
0.6% 188 Minimum Remove to Make Valid Parentheses String Stack
Medium 33
0.7% 189 Minimum Cost to Make Array Equal Array Binary Search Greedy Sorting Prefix Sum
Hard 33
0.5% 190 Clone Graph Hash Table Depth-First Search Breadth-First Search Graph Theory
Medium 33
0.7% 191 Maximum Earnings From Taxi Array Hash Table Binary Search Dynamic Programming Sorting
Medium 33
0.5% 192 Keys and Rooms Depth-First Search Breadth-First Search Graph Theory
Medium 33
0.8% 193 Rotate String String String Matching
Easy 33
0.7% 194 Candy Array Greedy
Hard 33
0.5% 195 Reverse Substrings Between Each Pair of Parentheses String Stack
Medium 33
0.7% 196 Valid Sudoku Array Hash Table Matrix
Medium 33
0.6% 197 Climbing Stairs Math Dynamic Programming Memoization
Easy 33
0.5% 198 Frog Jump Array Dynamic Programming
Hard 33
0.5% 199 Reverse Linked List II Linked List
Medium 33
0.5% 200 Meeting Rooms III Array Hash Table Sorting Heap (Priority Queue) Simulation
Hard 33
0.5% 201 Decrypt String from Alphabet to Integer Mapping String
Easy 33
0.8% 202 Number of Closed Islands Array Depth-First Search Breadth-First Search Union-Find Matrix
Medium 33
0.7% 203 Number of Music Playlists Math Dynamic Programming Combinatorics
Hard 33
0.6% 204 Invalid Transactions Array Hash Table String Sorting
Medium 33
0.3% 205 Distance to a Cycle in Undirected Graph Depth-First Search Breadth-First Search Graph Theory Topological Sort
Hard 33
0.7% 206 Open the Lock Array Hash Table String Breadth-First Search
Medium 33
0.6% 207 Sum Root to Leaf Numbers Tree Depth-First Search Binary Tree
Medium 33
0.7% 208 Longest Valid Parentheses String Dynamic Programming Stack
Hard 25
0.4% 209 Sudoku Solver Array Hash Table Backtracking Matrix
Hard 25
0.7% 210 Combination Sum Array Backtracking
Medium 25
0.8% 211 Jump Game II Array Dynamic Programming Greedy
Medium 25
0.4% 212 Insert Interval Array
Medium 25
0.5% 213 Text Justification Array String Simulation
Hard 25
0.5% 214 Decode Ways String Dynamic Programming
Medium 25
0.4% 215 Path Sum II Backtracking Tree Depth-First Search Binary Tree
Medium 25
0.6% 216 Find Peak Element Array Binary Search
Medium 25
0.5% 217 Rotate Array Array Math Two Pointers
Medium 25
0.5% 218 Invert Binary Tree Tree Depth-First Search Breadth-First Search Binary Tree
Easy 25
0.8% 219 Find the Duplicate Number Array Two Pointers Binary Search Bit Manipulation
Medium 25
0.6% 220 Validate IP Address String
Medium 25
0.3% 221 Remove Nth Node From End of List Linked List Two Pointers
Medium 25
0.5% 222 Design Circular Queue Array Linked List Design Queue
Medium 25
0.5% 223 Backspace String Compare Two Pointers String Stack Simulation
Easy 25
0.5% 224 K Closest Points to Origin Array Math Divide and Conquer Geometry Sorting Heap (Priority Queue) Quickselect
Medium 25
0.7% 225 Subarrays with K Different Integers Array Hash Table Sliding Window Counting
Hard 25
0.7% 226 Max Consecutive Ones III Array Binary Search Sliding Window Prefix Sum
Medium 25
0.7% 227 Design File System Hash Table String Design Trie
Medium 25
0.7% 228 Minimum Number of Steps to Make Two Strings Anagram Hash Table String Counting
Medium 25
0.8% 229 Sort Array by Increasing Frequency Array Hash Table Sorting
Easy 25
0.8% 230 Last Stone Weight Array Heap (Priority Queue)
Easy 25
0.7% 231 Swapping Nodes in a Linked List Linked List Two Pointers
Medium 25
0.7% 232 Max Stack Linked List Stack Design Doubly-Linked List Ordered Set
Hard 25
0.5% 233 Binary Search Array Binary Search
Easy 25
0.6% 234 Remove Duplicates from Sorted List II Linked List Two Pointers
Medium 25
0.5% 235 Minimum Cost to Cut a Stick Array Dynamic Programming Sorting
Hard 25
0.6% 236 Split Array Largest Sum Array Binary Search Dynamic Programming Greedy Prefix Sum
Hard 25
0.6% 237 Trapping Rain Water II Array Breadth-First Search Heap (Priority Queue) Matrix
Hard 25
0.6% 238 Subsets Array Backtracking Bit Manipulation
Medium 25
0.8% 239 Fraction to Recurring Decimal Hash Table Math String
Medium 25
0.3% 240 Count of Range Sum Array Binary Search Divide and Conquer Binary Indexed Tree Segment Tree Merge Sort Ordered Set
Hard 25
0.4% 241 Edit Distance String Dynamic Programming
Medium 25
0.6% 242 Minimum Operations to Halve Array Sum Array Greedy Heap (Priority Queue)
Medium 25
0.5% 243 Count Servers that Communicate Array Depth-First Search Breadth-First Search Union-Find Matrix Counting
Medium 25
0.7% 244 My Calendar I Array Binary Search Design Segment Tree Ordered Set
Medium 25
0.6% 245 Letter Tile Possibilities Hash Table String Backtracking Counting
Medium 25
0.8% 246 Maximize Greatness of an Array Array Two Pointers Greedy Sorting
Medium 25
0.6% 247 Linked List Cycle II Hash Table Linked List Two Pointers
Medium 25
0.6% 248 Serialize and Deserialize Binary Tree String Tree Depth-First Search Breadth-First Search Design Binary Tree
Hard 25
0.6% 249 Maximum Candies Allocated to K Children Array Binary Search
Medium 25
0.5% 250 Can Place Flowers Array Greedy
Easy 25
0.3% 251 Find All Duplicates in an Array Array Hash Table Sorting
Medium 25
0.8% 252 Basic Calculator III Math String Stack Recursion
Hard 25
0.5% 253 Cache With Time Limit Medium 25
0.8% 254 Maximum Employees to Be Invited to a Meeting Array Dynamic Programming Depth-First Search Graph Theory Topological Sort
Hard 25
0.6% 255 Plates Between Candles Array String Binary Search Prefix Sum
Medium 25
0.5% 256 Remove Linked List Elements Linked List Recursion
Easy 25
0.5% 257 Create Maximum Number Array Two Pointers Stack Greedy Monotonic Stack
Hard 25
0.4% 258 Nested List Weight Sum Depth-First Search Breadth-First Search
Medium 25
0.9% 259 Count and Say String
Medium 25
0.6% 260 Remove Invalid Parentheses String Backtracking Breadth-First Search
Hard 25
0.5% 261 Minimum Sideway Jumps Array Dynamic Programming Greedy
Medium 25
0.5% 262 Largest Divisible Subset Array Math Dynamic Programming Sorting
Medium 25
0.5% 263 Word Search II Array String Backtracking Trie Matrix
Hard 25
0.4% 264 Maximum Depth of Binary Tree Tree Depth-First Search Breadth-First Search Binary Tree
Easy 25
0.8% 265 Multiply Strings Math String Simulation
Medium 25
0.4% 266 Sparse Matrix Multiplication Array Hash Table Matrix
Medium 25
0.7% 267 Next Greater Element III Math Two Pointers String
Medium 25
0.4% 268 Swap Nodes in Pairs Linked List Recursion
Medium 25
0.7% 269 Remove K Digits String Stack Greedy Monotonic Stack
Medium 25
0.4% 270 Minimize Maximum of Array Array Binary Search Dynamic Programming Greedy Prefix Sum
Medium 25
0.5% 271 Greatest Common Divisor of Strings Math String
Easy 25
0.5% 272 3Sum Smaller Array Two Pointers Binary Search Sorting
Medium 25
0.5% 273 Merge Strings Alternately Two Pointers String
Easy 25
0.8% 274 Count Number of Nice Subarrays Array Hash Table Math Sliding Window Prefix Sum
Medium 25
0.8% 275 Evaluate Reverse Polish Notation Array Math Stack
Medium 25
0.6% 276 Merge Nodes in Between Zeros Linked List Simulation
Medium 25
0.9% 277 Missing Number Array Hash Table Math Binary Search Bit Manipulation Sorting
Easy 25
0.7% 278 Encode and Decode Strings Array String Design
Medium 25
0.5% 279 Minimum Insertion Steps to Make a String Palindrome String Dynamic Programming
Hard 25
0.7% 280 Design Add and Search Words Data Structure String Depth-First Search Design Trie
Medium 25
0.5% 281 Boundary of Binary Tree Tree Depth-First Search Binary Tree
Medium 25
0.5% 282 Water and Jug Problem Math Depth-First Search Breadth-First Search
Medium 25
0.5% 283 Minimum Cost Homecoming of a Robot in a Grid Array Greedy
Medium 25
0.5% 284 The kth Factor of n Math Number Theory
Medium 25
0.7% 285 Number of Valid Words in a Sentence String
Easy 25
0.3% 286 Minimum Number of Increments on Subarrays to Form a Target Array Array Dynamic Programming Stack Greedy Monotonic Stack
Hard 25
0.8% 287 Collect Coins in a Tree Array Tree Graph Theory Topological Sort
Hard 25
0.4% 288 Kth Missing Positive Number Array Binary Search
Easy 25
0.6% 289 Maximum Size Subarray Sum Equals k Array Hash Table Prefix Sum
Medium 25
0.5% 290 Add Two Numbers II Linked List Math Stack
Medium 25
0.6% 291 Find in Mountain Array Array Binary Search Interactive
Hard 25
0.4% 292 Single Number III Array Bit Manipulation
Medium 25
0.7% 293 Largest Rectangle in Histogram Array Stack Monotonic Stack
Hard 25
0.5% 294 Counting Bits Dynamic Programming Bit Manipulation
Easy 25
0.8% 295 Merge Operations to Turn Array Into a Palindrome Array Two Pointers Greedy
Medium 25
0.7% 296 Minimum Edge Reversals So Every Node Is Reachable Dynamic Programming Depth-First Search Breadth-First Search Graph Theory
Hard 25
0.6% 297 Wildcard Matching String Dynamic Programming Greedy Recursion
Hard 25
0.3% 298 Least Number of Unique Integers after K Removals Array Hash Table Greedy Sorting Counting
Medium 25
0.6% 299 Binary Tree Level Order Traversal II Tree Breadth-First Search Binary Tree
Medium 25
0.7% 300 Redundant Connection Depth-First Search Breadth-First Search Union-Find Graph Theory
Medium 25
0.7% 301 Minimum Knight Moves Breadth-First Search
Medium 25
0.4% 302 Bus Routes Array Hash Table Breadth-First Search
Hard 25
0.5% 303 Minimum Cost Path with Edge Reversals Graph Theory Heap (Priority Queue) Shortest Path
Medium 25
0.6% 304 Avoid Flood in The City Array Hash Table Binary Search Greedy Heap (Priority Queue)
Medium 25
0.4% 305 Happy Number Hash Table Math Two Pointers
Easy 25
0.6% 306 Generate Schedule Array Math Greedy
Medium 25
0.2% 307 Flood Fill Array Depth-First Search Breadth-First Search Matrix
Easy 25
0.7% 308 Percentage of Users Attended a Contest Database
Easy 25
0.6% 309 Reverse Nodes in k-Group Linked List Recursion
Hard 25
0.7% 310 Design Hit Counter Array Binary Search Design Queue Data Stream
Medium 25
0.7% 311 Simple Bank System Array Hash Table Design Simulation
Medium 25
0.7% 312 Find Minimum Diameter After Merging Two Trees Tree Depth-First Search Breadth-First Search Graph Theory
Hard 25
0.6% 313 Path Sum III Tree Depth-First Search Binary Tree
Medium 25
0.5% 314 Monthly Transactions I Database
Medium 25
0.6%