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
Facebook(79)
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