1 Two Sum 23.0% Easy 21 Merge Two Sorted Lists 35.4% Easy 23 Merge k Sorted Lists 23.3% Hard 33 Search in Rotated Sorted Array 30.2% Hard 34 Search for a Range 29.1% Medium 46 Permutations 35.7% Medium 47 Permutations II 28.0% Medium 50 Pow(x, n) 27.9% Medium 53 Maximum Subarray 36.6% Medium 56 Merge Intervals 25.3% Hard 57 Insert Interval 23.8% Hard 65 Valid Number 12.1% Hard 68 Text Justification 16.1% Hard 76 Minimum Window Substring 21.2% Hard 101 Symmetric Tree 33.9% Easy 102 Binary Tree Level Order Traversal 32.7% Easy 103 Binary Tree Zigzag Level Order Traversal 28.6% Medium 104 Maximum Depth of Binary Tree 47.8% Easy 127 Word Ladder 19.6% Medium 149 Max Points on a Line 14.2% Hard 150 Evaluate Reverse Polish Notation 23.5% Medium 152 Maximum Product Subarray 22.1% Medium 156 Binary Tree Upside Down 38.3% Medium 170 Two Sum III – Data structure design 24.0% Easy 173 Binary Search Tree Iterator 34.5% Medium 187 Repeated DNA Sequences 25.2% Medium 198 House Robber 34.2% Easy 205 Isomorphic Strings 29.5% Easy 236 Lowest Common Ancestor of a Binary Tree 28.8% Medium 238 Product of Array Except Self 42.6% Medium 243 Shortest Word Distance 46.3% Easy 244 Shortest Word Distance II 35.3% Medium 245 Shortest Word Distance III 46.0% Medium 254 Factor Combinations 34.7% Medium 256 Paint House 42.6% Medium 277 Find the Celebrity 35.1% Medium 297 Serialize and Deserialize Binary Tree 27.8% Hard 311 Sparse Matrix Multiplication 47.2% Medium 339 Nested List Weight Sum 54.7% Easy
Median of Two Sorted Arrays 18.6% Hard 10 Regular Expression Matching 22.0% Hard 17 Letter Combinations of a Phone Number 28.6% Medium 20 Valid Parentheses 29.3% Easy 22 Generate Parentheses 36.9% Medium 23 Merge k Sorted Lists 23.3% Hard 31 Next Permutation 26.5% Medium 42 Trapping Rain Water 32.2% Hard 44 Wildcard Matching 17.4% Hard 50 Pow(x, n) 27.9% Medium 54 Spiral Matrix 22.5% Medium 56 Merge Intervals 25.3% Hard 57 Insert Interval 23.8% Hard 66 Plus One 33.5% Easy 128 Longest Consecutive Sequence 32.1% Hard 133 Clone Graph 24.9% Medium 139 Word Break 25.2% Medium 140 Word Break II 19.7% Hard 146 LRU Cache 15.8% Hard 155 Min Stack 22.0% Easy 158 Read N Characters Given Read4 II – Call multiple times 23.4% Hard 159 Longest Substring with At Most Two Distinct Characters 34.7% Hard 162 Find Peak Element 33.0% Medium 163 Missing Ranges 29.2% Medium 166 Fraction to Recurring Decimal 15.1% Medium 173 Binary Search Tree Iterator 34.5% Medium 200 Number of Islands 27.6% Medium 208 Implement Trie (Prefix Tree) 25.3% Medium 212 Word Search II 19.3% Hard 214 Shortest Palindrome 19.7% Hard 218 The Skyline Problem 22.0% Hard 224 Basic Calculator 22.1% Hard 228 Summary Ranges 24.1% Medium 230 Kth Smallest Element in a BST 37.6% Medium 231 Power of Two 36.4% Easy 239 Sliding Window Maximum 27.3% Hard 240 Search a 2D Matrix II 34.4% Medium 246 Strobogrammatic Number 36.3% Easy 247 Strobogrammatic Number II 34.1% Medium 249 Group Shifted Strings 31.3% Easy 251 Flatten 2D Vector 33.8% Medium 253 Meeting Rooms II 34.6% Medium 257 Binary Tree Paths 28.4% Easy 259 3Sum Smaller 38.2% Medium 261 Graph Valid Tree 32.5% Medium 266 Palindrome Permutation 50.4% Easy 269 Alien Dictionary 22.9% Hard 270 Closest Binary Search Tree Value 34.3% Easy 271 Encode and Decode Strings 27.1% Medium 272 Closest Binary Search Tree Value II 33.1% Hard 274 H-Index 29.3% Medium 276 Paint Fence 30.9% Easy 279 Perfect Squares 32.5% Medium 280 Wiggle Sort 49.5% Medium 281 Zigzag Iterator 42.8% Medium 282 Expression Add Operators 24.8% Hard 284 Peeking Iterator 33.5% Medium 286 Walls and Gates 37.2% Medium 288 Unique Word Abbreviation 15.7% Easy 289 Game of Life 34.2% Medium 293 Flip Game 49.5% Easy 294 Flip Game II 41.3% Medium 295 Find Median from Data Stream 22.0% Hard 297 Serialize and Deserialize Binary Tree 27.8% Hard 298 Binary Tree Longest Consecutive Sequence 36.9% Medium 302 Smallest Rectangle Enclosing Black Pixels 39.0% Hard 305 Number of Islands II 34.0% Hard 308 Range Sum Query 2D – Mutable 21.6% Hard 309 Best Time to Buy and Sell Stock with Cooldown 36.6% Medium 310 Minimum Height Trees 26.6% Medium 312 Burst Balloons 36.4% Hard 313 Super Ugly Number 33.9% Medium 314 Binary Tree Vertical Order Traversal 30.3% Medium 315 Count of Smaller Numbers After Self 30.1% Hard 316 Remove Duplicate Letters 24.9% Hard 317 Shortest Distance from All Buildings 31.1% Hard 318 Maximum Product of Word Lengths 39.6% Medium 320 Generalized Abbreviation 40.8% Medium 321 Create Maximum Number 20.8% Hard 323 Number of Connected Components in an Undirected Graph 42.8% Medium 324 Wiggle Sort II 22.1% Medium 326 Power of Three 36.5% Easy 327 Count of Range Sum 25.9% Hard 329 Longest Increasing Path in a Matrix 31.2% Hard 330 Patching Array 28.9% Medium 331 Verify Preorder Serialization of a Binary Tree 31.7% Medium 332 Reconstruct Itinerary 23.8% Medium 336 Palindrome Pairs 19.5% Hard 340 Longest Substring with At Most K Distinct Characters 37.2% Hard 341 Flatten Nested List Iterator 19.8% Medium
1 Two Sum 23.0% Easy 8 String to Integer (atoi) 13.5% Easy 10 Regular Expression Matching 22.0% Hard 13 Roman to Integer 39.2% Easy 17 Letter Combinations of a Phone Number 28.6% Medium 22 Generate Parentheses 36.9% Medium 23 Merge k Sorted Lists 23.3% Hard 24 Swap Nodes in Pairs 35.1% Easy 33 Search in Rotated Sorted Array 30.2% Hard 36 Valid Sudoku 30.5% Easy 37 Sudoku Solver 24.8% Hard 39 Combination Sum 30.9% Medium 49 Group Anagrams 27.4% Medium 54 Spiral Matrix 22.5% Medium 76 Minimum Window Substring 21.2% Hard 78 Subsets 31.3% Medium 91 Decode Ways 17.5% Medium 104 Maximum Depth of Binary Tree 47.8% Easy 121 Best Time to Buy and Sell Stock 36.0% Easy 125 Valid Palindrome 23.8% Easy 133 Clone Graph 24.9% Medium 138 Copy List with Random Pointer 26.1% Hard 139 Word Break 25.2% Medium 140 Word Break II 19.7% Hard 146 LRU Cache 15.8% Hard 155 Min Stack 22.0% Easy 161 One Edit Distance 28.4% Medium 171 Excel Sheet Column Number 41.5% Easy 186 Reverse Words in a String II 29.1% Medium 202 Happy Number 36.5% Easy 206 Reverse Linked List 39.4% Easy 208 Implement Trie (Prefix Tree) 25.3% Medium 230 Kth Smallest Element in a BST 37.6% Medium 242 Valid Anagram 41.7% Easy 249 Group Shifted Strings 31.3% Easy 254 Factor Combinations 34.7% Medium 262 Trips and Users 16.1% Hard 266 Palindrome Permutation 50.4% Easy 290 Word Pattern 29.0% Easy 291 Word Pattern II 34.8% Hard 297 Serialize and Deserialize Binary Tree 27.8% Har 337 House Robber III 37.0% Medium
1 Two Sum 23.0% Easy 2 Add Two Numbers 23.0% Medium 10 Regular Expression Matching 22.0% Hard 20 Valid Parentheses 29.3% Easy 23 Merge k Sorted Lists 23.3% Hard 68 Text Justification 16.1% Hard 108 Convert Sorted Array to Binary Search Tree 37.2% Medium 136 Single Number 49.6% Medium 160 Intersection of Two Linked Lists 30.2% Easy 190 Reverse Bits 29.3% Easy 198 House Robber 34.2% Easy 202 Happy Number 36.5% Easy 212 Word Search II 19.3% Hard 217 Contains Duplicate 41.1% Easy 219 Contains Duplicate II 29.9% Easy 220 Contains Duplicate III 18.5% Medium 221 Maximal Square 23.5% Medium 251 Flatten 2D Vector 33.8% Medium 269 Alien Dictionary 22.9% Hard 336 Palindrome Pairs 19.5% Hard
1 Two Sum 23.0% Easy 10 Regular Expression Matching 22.0% Hard 13 Roman to Integer 39.2% Easy 15 3Sum 18.8% Medium 17 Letter Combinations of a Phone Number 28.6% Medium 20 Valid Parentheses 29.3% Easy 23 Merge k Sorted Lists 23.3% Hard 25 Reverse Nodes in k-Group 27.5% Hard 26 Remove Duplicates from Sorted Array 33.4% Easy 28 Implement strStr() 24.8% Easy 33 Search in Rotated Sorted Array 30.2% Hard 38 Count and Say 28.9% Easy 43 Multiply Strings 23.4% Medium 44 Wildcard Matching 17.4% Hard 49 Group Anagrams 27.4% Medium 50 Pow(x, n) 27.9% Medium 56 Merge Intervals 25.3% Hard 57 Insert Interval 23.8% Hard 67 Add Binary 27.4% Easy 69 Sqrt(x) 25.2% Medium 71 Simplify Path 21.9% Medium 75 Sort Colors 34.7% Medium 76 Minimum Window Substring 21.2% Hard 78 Subsets 31.3% Medium 79 Word Search 22.9% Medium 80 Remove Duplicates from Sorted Array II 32.7% Medium 85 Maximal Rectangle 23.4% Hard 88 Merge Sorted Array 30.0% Easy 90 Subsets II 30.5% Medium 91 Decode Ways 17.5% Medium 98 Validate Binary Search Tree 20.9% Medium 102 Binary Tree Level Order Traversal 32.7% Easy 117 Populating Next Right Pointers in Each Node II 32.8% Hard 121 Best Time to Buy and Sell Stock 36.0% Easy 125 Valid Palindrome 23.8% Easy 127 Word Ladder 19.6% Medium 128 Longest Consecutive Sequence 32.1% Hard 133 Clone Graph 24.9% Medium 139 Word Break 25.2% Medium 146 LRU Cache 15.8% Hard 157 Read N Characters Given Read4 29.5% Easy 158 Read N Characters Given Read4 II – Call multiple times 23.4% Hard 161 One Edit Distance 28.4% Medium 168 Excel Sheet Column Title 21.6% Easy 173 Binary Search Tree Iterator 34.5% Medium 200 Number of Islands 27.6% Medium 206 Reverse Linked List 39.4% Easy 208 Implement Trie (Prefix Tree) 25.3% Medium 209 Minimum Size Subarray Sum 26.8% Medium 210 Course Schedule II 21.0% Medium 211 Add and Search Word – Data structure design 20.2% Medium 215 Kth Largest Element in an Array 33.1% Medium 218 The Skyline Problem 22.0% Hard 221 Maximal Square 23.5% Medium 234 Palindrome Linked List 28.0% Easy 235 Lowest Common Ancestor of a Binary Search Tree 37.7% Easy 236 Lowest Common Ancestor of a Binary Tree 28.8% Medium 238 Product of Array Except Self 42.6% Medium 252 Meeting Rooms 41.6% Easy 253 Meeting Rooms II 34.6% Medium 257 Binary Tree Paths 28.4% Easy 261 Graph Valid Tree 32.5% Medium 265 Paint House II 35.6% Hard 269 Alien Dictionary 22.9% Hard 273 Integer to English Words 18.7% Hard 274 H-Index 29.3% Medium 275 H-Index II 32.5% Medium 277 Find the Celebrity 35.1% Medium 278 First Bad Version 22.4% Easy 282 Expression Add Operators 24.8% Hard 283 Move Zeroes 44.0% Easy 285 Inorder Successor in BST 35.6% Medium 286 Walls and Gates 37.2% Medium 297 Serialize and Deserialize Binary Tree 27.8% Hard 301 Remove Invalid Parentheses 31.9% Hard 311 Sparse Matrix Multiplication 47.2% Medium 314 Binary Tree Vertical Order Traversal 30.3% Medium 325 Maximum Size Subarray Sum Equals k 39.9% Easy 334 Increasing Triplet Subsequence 33.2% Medium
Regular Expression Matching 22.0% Hard 12 Integer to Roman 38.8% Medium 20 Valid Parentheses 29.3% Easy 23 Merge k Sorted Lists 23.3% Hard 42 Trapping Rain Water 32.2% Hard 43 Multiply Strings 23.4% Medium 56 Merge Intervals 25.3% Hard 60 Permutation Sequence 25.1% Medium 118 Pascal’s Triangle 33.3% Easy 140 Word Break II 19.7% Hard 146 LRU Cache 15.8% Hard 149 Max Points on a Line 14.2% Hard 161 One Edit Distance 28.4% Medium 202 Happy Number 36.5% Easy 206 Reverse Linked List 39.4% Easy 208 Implement Trie (Prefix Tree) 25.3% Medium 218 The Skyline Problem 22.0% Hard 235 Lowest Common Ancestor of a Binary Search Tree 37.7% Easy 251 Flatten 2D Vector 33.8% Medium 269 Alien Dictionary 22.9% Hard 296 Best Meeting Point 46.7% Hard
4 Median of Two Sorted Arrays 18.6% Hard 20 Valid Parentheses 29.3% Easy 22 Generate Parentheses 36.9% Medium 42 Trapping Rain Water 32.2% Hard 52 N-Queens II 39.2% Hard 109 Convert Sorted List to Binary Search Tree 30.4% Medium 125 Valid Palindrome 23.8% Easy 146 LRU Cache 15.8% Hard 155 Min Stack 22.0% Easy 168 Excel Sheet Column Title 21.6% Easy 169 Majority Element 41.1% Easy 200 Number of Islands 27.6% Medium 206 Reverse Linked List 39.4% Easy 207 Course Schedule 26.8% Medium 210 Course Schedule II 21.0% Medium 229 Majority Element II 25.6% Medium 239 Sliding Window Maximum 27.3% Hard 251 Flatten 2D Vector 33.8% Medium 255 Verify Preorder Sequence in Binary Search Tree 37.1% Medium 261 Graph Valid Tree 32.5% Medium 317 Shortest Distance from All Buildings 31.1% Hard
1 Two Sum 23.0% Easy 2 Add Two Numbers 23.0% Medium 3 Longest Substring Without Repeating Characters 21.9% Medium 5 Longest Palindromic Substring 23.0% Medium 8 String to Integer (atoi) 13.5% Easy 15 3Sum 18.8% Medium 17 Letter Combinations of a Phone Number 28.6% Medium 20 Valid Parentheses 29.3% Easy 21 Merge Two Sorted Lists 35.4% Easy 23 Merge k Sorted Lists 23.3% Hard 42 Trapping Rain Water 32.2% Hard 48 Rotate Image 34.6% Medium 49 Group Anagrams 27.4% Medium 78 Subsets 31.3% Medium 89 Gray Code 36.3% Medium 98 Validate Binary Search Tree 20.9% Medium 102 Binary Tree Level Order Traversal 32.7% Easy 121 Best Time to Buy and Sell Stock 36.0% Easy 126 Word Ladder II 13.6% Hard 127 Word Ladder 19.6% Medium 138 Copy List with Random Pointer 26.1% Hard 139 Word Break 25.2% Medium 141 Linked List Cycle 37.0% Medium 146 LRU Cache 15.8% Hard 155 Min Stack 22.0% Easy 160 Intersection of Two Linked Lists 30.2% Easy 167 Two Sum II – Input array is sorted 47.8% Medium 186 Reverse Words in a String II 29.1% Medium 199 Binary Tree Right Side View 34.3% Medium 200 Number of Islands 27.6% Medium 204 Count Primes 24.2% Easy 206 Reverse Linked List 39.4% Easy 215 Kth Largest Element in an Array 33.1% Medium 234 Palindrome Linked List 28.0% Easy 235 Lowest Common Ancestor of a Binary Search Tree 37.7% Easy 236 Lowest Common Ancestor of a Binary Tree 28.8% Medium 238 Product of Array Except Self 42.6% Medium 239 Sliding Window Maximum 27.3% Hard 240 Search a 2D Matrix II 34.4% Medium 242 Valid Anagram 41.7% Easy 297 Serialize and Deserialize Binary Tree 27.8% Hard
1 Two Sum 23.0% Easy 2 Add Two Numbers 23.0% Medium 4 Median of Two Sorted Arrays 18.6% Hard 5 Longest Palindromic Substring 23.0% Medium 8 String to Integer (atoi) 13.5% Easy 13 Roman to Integer 39.2% Easy 15 3Sum 18.8% Medium 20 Valid Parentheses 29.3% Easy 21 Merge Two Sorted Lists 35.4% Easy 23 Merge k Sorted Lists 23.3% Hard 24 Swap Nodes in Pairs 35.1% Easy 25 Reverse Nodes in k-Group 27.5% Hard 26 Remove Duplicates from Sorted Array 33.4% Easy 28 Implement strStr() 24.8% Easy 33 Search in Rotated Sorted Array 30.2% Hard 46 Permutations 35.7% Medium 47 Permutations II 28.0% Medium 48 Rotate Image 34.6% Medium 53 Maximum Subarray 36.6% Medium 54 Spiral Matrix 22.5% Medium 55 Jump Game 28.2% Medium 56 Merge Intervals 25.3% Hard 71 Simplify Path 21.9% Medium 73 Set Matrix Zeroes 33.4% Medium 75 Sort Colors 34.7% Medium 79 Word Search 22.9% Medium 88 Merge Sorted Array 30.0% Easy 91 Decode Ways 17.5% Medium 94 Binary Tree Inorder Traversal 39.6% Medium 98 Validate Binary Search Tree 20.9% Medium 101 Symmetric Tree 33.9% Easy 102 Binary Tree Level Order Traversal 32.7% Easy 103 Binary Tree Zigzag Level Order Traversal 28.6% Medium 106 Construct Binary Tree from Inorder and Postorder Traversal 29.0% Medium 112 Path Sum 31.3% Easy 114 Flatten Binary Tree to Linked List 31.0% Medium 116 Populating Next Right Pointers in Each Node 36.5% Medium 117 Populating Next Right Pointers in Each Node II 32.8% Hard 121 Best Time to Buy and Sell Stock 36.0% Easy 124 Binary Tree Maximum Path Sum 23.3% Hard 125 Valid Palindrome 23.8% Easy 138 Copy List with Random Pointer 26.1% Hard 141 Linked List Cycle 37.0% Medium 146 LRU Cache 15.8% Hard 151 Reverse Words in a String 15.7% Medium 153 Find Minimum in Rotated Sorted Array 36.1% Medium 160 Intersection of Two Linked Lists 30.2% Easy 162 Find Peak Element 33.0% Medium 165 Compare Version Numbers 17.4% Easy 168 Excel Sheet Column Title 21.6% Easy 171 Excel Sheet Column Number 41.5% Easy 173 Binary Search Tree Iterator 34.5% Medium 174 Dungeon Game 20.8% Hard 186 Reverse Words in a String II 29.1% Medium 189 Rotate Array 21.1% Easy 191 Number of 1 Bits 37.5% Easy 200 Number of Islands 27.6% Medium 204 Count Primes 24.2% Easy 206 Reverse Linked List 39.4% Easy 208 Implement Trie (Prefix Tree) 25.3% Medium 212 Word Search II 19.3% Hard 213 House Robber II 30.5% Medium 215 Kth Largest Element in an Array 33.1% Medium 218 The Skyline Problem 22.0% Hard 232 Implement Queue using Stacks 33.9% Easy 235 Lowest Common Ancestor of a Binary Search Tree 37.7% Easy 236 Lowest Common Ancestor of a Binary Tree 28.8% Medium 237 Delete Node in a Linked List 43.7% Easy 238 Product of Array Except Self 42.6% Medium 258 Add Digits 48.4% Easy 268 Missing Number 40.0% Medium 270 Closest Binary Search Tree Value 34.3% Easy 273 Integer to English Words 18.7% Hard 285 Inorder Successor in BST 35.6% Medium 297 Serialize and Deserialize Binary Tree 27.8% Hard 300 Longest Increasing Subsequence 34.2% Medium 333 Largest BST Subtree 26.5% Medium
36 Valid Sudoku 30.5% Easy 39 Combination Sum 30.9% Medium 44 Wildcard Matching 17.4% Hard 96 Unique Binary Search Trees 37.4% Medium 127 Word Ladder 19.6% Medium 140 Word Break II 19.7% Hard 146 LRU Cache 15.8% Hard 151 Reverse Words in a String 15.7% Medium 155 Min Stack 22.0% Easy 161 One Edit Distance 28.4% Medium 206 Reverse Linked List 39.4% Easy 269 Alien Dictionary 22.9% Hard 270 Closest Binary Search Tree Value 34.3% Easy 289 Game of Life 34.2% Medium 314 Binary Tree Vertical Order Traversal 30.3% Medium
1 Two Sum 23.0% Easy 4 Median of Two Sorted Arrays 18.6% Hard 7 Reverse Integer 23.6% Easy 21 Merge Two Sorted Lists 35.4% Easy 28 Implement strStr() 24.8% Easy 36 Valid Sudoku 30.5% Easy 42 Trapping Rain Water 32.2% Hard 48 Rotate Image 34.6% Medium 69 Sqrt(x) 25.2% Medium 70 Climbing Stairs 36.7% Easy 102 Binary Tree Level Order Traversal 32.7% Easy 104 Maximum Depth of Binary Tree 47.8% Easy 118 Pascal’s Triangle 33.3% Easy 149 Max Points on a Line 14.2% Hard 151 Reverse Words in a String 15.7% Medium 165 Compare Version Numbers 17.4% Easy 190 Reverse Bits 29.3% Easy 191 Number of 1 Bits 37.5% Easy 206 Reverse Linked List 39.4% Easy 207 Course Schedule 26.8% Medium 215 Kth Largest Element in an Array 33.1% Medium 221 Maximal Square 23.5% Medium 236 Lowest Common Ancestor of a Binary Tree 28.8% Medium 237 Delete Node in a Linked List 43.7% Easy 238 Product of Array Except Self 42.6% Medium 240 Search a 2D Matrix II 34.4% Medium 257 Binary Tree Paths 28.4% Easy 284 Peeking Iterator 33.5% Medium
1 Two Sum 23.0% Easy 4 Median of Two Sorted Arrays 18.6% Hard 13 Roman to Integer 39.2% Easy 104 Maximum Depth of Binary Tree 47.8% Easy 139 Word Break 25.2% Medium 141 Linked List Cycle 37.0% Medium 146 LRU Cache 15.8% Hard 206 Reverse Linked List 39.4% Easy 217 Contains Duplicate 41.1% Easy 284 Peeking Iterator 33.5% Medium 297 Serialize and Deserialize Binary Tree 27.8% Hard
1 Two Sum 23.0% Easy 4 Median of Two Sorted Arrays 18.6% Hard 17 Letter Combinations of a Phone Number 28.6% Medium 140 Word Break II 19.7% Hard 289 Game of Life 34.2% Medium 290 Word Pattern 29.0% Easy 291 Word Pattern II 34.8% Hard
1 Two Sum 23.0% Easy 2 Add Two Numbers 23.0% Medium 3 Longest Substring Without Repeating Characters 21.9% Medium 5 Longest Palindromic Substring 23.0% Medium 7 Reverse Integer 23.6% Easy 8 String to Integer (atoi) 13.5% Easy 11 Container With Most Water 34.5% Medium 13 Roman to Integer 39.2% Easy 15 3Sum 18.8% Medium 16 3Sum Closest 29.0% Medium 20 Valid Parentheses 29.3% Easy 24 Swap Nodes in Pairs 35.1% Easy 26 Remove Duplicates from Sorted Array 33.4% Easy 33 Search in Rotated Sorted Array 30.2% Hard 42 Trapping Rain Water 32.2% Hard 49 Group Anagrams 27.4% Medium 50 Pow(x, n) 27.9% Medium 53 Maximum Subarray 36.6% Medium 56 Merge Intervals 25.3% Hard 62 Unique Paths 36.2% Medium 63 Unique Paths II 29.3% Medium 69 Sqrt(x) 25.2% Medium 79 Word Search 22.9% Medium 88 Merge Sorted Array 30.0% Easy 98 Validate Binary Search Tree 20.9% Medium 100 Same Tree 43.2% Easy 101 Symmetric Tree 33.9% Easy 102 Binary Tree Level Order Traversal 32.7% Easy 103 Binary Tree Zigzag Level Order Traversal 28.6% Medium 105 Construct Binary Tree from Preorder and Inorder Traversal 28.6% Medium 110 Balanced Binary Tree 34.0% Easy 113 Path Sum II 28.2% Medium 117 Populating Next Right Pointers in Each Node II 32.8% Hard 121 Best Time to Buy and Sell Stock 36.0% Easy 122 Best Time to Buy and Sell Stock II 42.2% Medium 131 Palindrome Partitioning 27.6% Medium 138 Copy List with Random Pointer 26.1% Hard 139 Word Break 25.2% Medium 141 Linked List Cycle 37.0% Medium 146 LRU Cache 15.8% Hard 151 Reverse Words in a String 15.7% Medium 155 Min Stack 22.0% Easy 158 Read N Characters Given Read4 II – Call multiple times 23.4% Hard 160 Intersection of Two Linked Lists 30.2% Easy 172 Factorial Trailing Zeroes 32.7% Easy 189 Rotate Array 21.1% Easy 206 Reverse Linked List 39.4% Easy 208 Implement Trie (Prefix Tree) 25.3% Medium 215 Kth Largest Element in an Array 33.1% Medium 225 Implement Stack using Queues 30.5% Easy 230 Kth Smallest Element in a BST 37.6% Medium 232 Implement Queue using Stacks 33.9% Easy 268 Missing Number 40.0% Medium 274 H-Index 29.3% Medium 283 Move Zeroes 44.0% Easy 287 Find the Duplicate Number 38.5% Hard 297 Serialize and Deserialize Binary Tree 27.8% Hard
1 Two Sum 23.0% Easy 3 Longest Substring Without Repeating Characters 21.9% Medium 14 Longest Common Prefix 28.1% Easy 49 Group Anagrams 27.4% Medium 56 Merge Intervals 25.3% Hard 126 Word Ladder II 13.6% Hard 127 Word Ladder 19.6% Medium 151 Reverse Words in a String 15.7% Medium 206 Reverse Linked List 39.4% Easy 207 Course Schedule 26.8% Medium 218 The Skyline Problem 22.0% Hard 242 Valid Anagram 41.7% Easy
136 Single Number 49.6% Medium 146 LRU Cache 15.8% Hard 217 Contains Duplicate 41.1% Easy 219 Contains Duplicate II 29.9% Easy 220 Contains Duplicate III 18.5% Medium 303 Range Sum Query – Immutable 24.4% Easy 325 Maximum Size Subarray Sum Equals k 39.9% Easy
1 Two Sum 23.0% Easy 2 Add Two Numbers 23.0% Medium 3 Longest Substring Without Repeating Characters 21.9% Medium 4 Median of Two Sorted Arrays 18.6% Hard 15 3Sum 18.8% Medium 70 Climbing Stairs 36.7% Easy 169 Majority Element 41.1% Easy 195 Tenth Line 32.4% Easy 206 Reverse Linked List 39.4% Easy 237 Delete Node in a Linked List 43.7% Easy 258 Add Digits 48.4% Easy 292 Nim Game 52.7% Easy