Leetcode LeetCode Solutions in Java and Go # Title Solutions Difficulty 1 Two Sum Java Go Easy 2 Add Two Numbers Java Go Medium 3 Longest Substring Without Repeating Characters Java Go Medium 11 Container With Most Water Medium 15 3Sum Java Go Medium 17 Letter Combinations of a Phone Number Java Go Medium 20 Valid Parentheses Easy 21 Merge Two Sorted Lists Easy 22 Generate Parentheses Java Go Medium 23 Merge k Sorted Lists Hard 33 Search in Rotated Sorted Array Medium 34 Find First and Last Position of Element in Sorted Array Medium 35 Search Insert Position Easy 36 Valid Sudoku Medium 37 Sudoku Solver Hard 39 Combination Sum Java Go Medium 46 Permutations Java Go Medium 47 Permutations II Medium 50 Pow(x, n) Java Go Medium 51 N-Queens Hard 52 N-Queens II Hard 53 Maximum Subarray Easy 56 Merge Intervals Medium 62 Unique Paths Medium 63 Unique Paths II Medium 64 Minimum Path Sum Medium 69 Sqrt(x) Easy 70 Climbing Stairs Java Go Easy 72 Edit Distance Hard 73 Set Matrix Zeroes Java Go Medium 74 Search a 2D Matrix Medium 75 Sort Colors Medium 78 Subsets Java Go Medium 79 Word Search Medium 91 Decode Ways Medium 94 Binary Tree Inorder Traversal Java Go Medium 98 Validate Binary Search Tree Java Go Medium 100 Same Tree Java Go Easy 101 Symmetric Tree Java Go Easy 102 Binary Tree Level Order Traversal Java Go Medium 103 Binary Tree Zigzag Level Order Traversal Java Go Medium 104 Maximum Depth of Binary Tree Java Go Easy 105 Construct Binary Tree from Preorder and Inorder Traversal Java Go Medium 106 Construct Binary Tree from Inorder and Postorder Traversal Java Go Medium 107 Binary Tree Level Order Traversal II Java Go Easy 108 Convert Sorted Array to Binary Search Tree Java Go Easy 110 Balanced Binary Tree Java Go Easy 111 Minimum Depth of Binary Tree Java Go Easy 112 Path Sum Java Go Easy 113 Path Sum II Java Go Medium 114 Flatten Binary Tree to Linked List Java Go Medium 116 Populating Next Right Pointers in Each Node Java Go Medium 117 Populating Next Right Pointers in Each Node II Java Go Medium 120 Triangle Medium 121 Best Time to Buy and Sell Stock Easy 122 Best Time to Buy and Sell Stock II Easy 124 Binary Tree Maximum Path Sum Java Go Hard 125 Valid Palindrome Easy 127 Word Ladder Medium 133 Clone Graph Medium 136 Single Number Java Go Easy 144 Binary Tree Preorder Traversal Java Go Medium 145 Binary Tree Postorder Traversal Java Go Hard 146 LRU Cache Medium 147 Insertion Sort List Medium 148 Sort List Medium 152 Maximum Product Subarray Medium 153 Find Minimum in Rotated Sorted Array Medium 162 Find Peak Element Medium 167 Two Sum II - Input array is sorted Easy 191 Number of 1 Bits Easy 198 House Robber Easy 200 Number of Islands Medium 202 Happy Number Java Go Easy 203 Remove Linked List Elements Easy 206 Reverse Linked List Easy 207 Course Schedule Medium 210 Course Schedule II Medium 213 House Robber II Medium 221 Maximal Square Medium 226 Invert Binary Tree Java Go Easy 235 Lowest Common Ancestor of a Binary Search Tree Java Go Easy 236 Lowest Common Ancestor of a Binary Tree Java Go Medium 240 Search a 2D Matrix II Medium 263 Ugly Number Easy 270 Closest Binary Search Tree Value Easy 279 Perfect Squares Medium 287 Find the Duplicate Number Medium 300 Longest Increasing Subsequence Medium 310 Minimum Height Trees Medium 322 Coin Change Medium 332 Reconstruct Itinerary Medium 337 House Robber III Medium 338 Counting Bits Medium 367 Valid Perfect Square Easy 371 Sum of Two Integers Easy 437 Path Sum III Java Go Easy 450 Delete Node in a BST Java Go Medium 504 Base 7 Easy 509 Fibonacci Number Easy 518 Coin Change 2 Medium 538 Convert BST to Greater Tree Java Go Easy 540 Single Element in a Sorted Array Medium 543 Diameter of Binary Tree Java Go Easy 572 Subtree of Another Tree Java Go Easy 617 Merge Two Binary Trees Java Go Easy 695 Max Area of Island Medium 700 Search in a Binary Search Tree Java Go Easy 746 Min Cost Climbing Stairs Easy 994 Rotting Oranges Easy 1103 Distribute Candies to People Easy 1143 Longest Common Subsequence Medium