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
Microsoft(77)
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