Invert a binary tree. Example: Input: 4 / \ 2 7 / \ / \1 3 6 9 Output: 4 / \ 7 2 / \ / \9 6 3 1 Trivia:This problem was inspired by this original tweet by Max Howell: Google: 90% of our engineers use the softw
Solution1: class Solution { public TreeNode invertTree(TreeNode root) { if (root == null) return null; TreeNode tmp = root.left; root.left = invertTree(root.right); root.right =
