LeetCode - Tree - Invert Binary Tree Invert a binary tree. Example: Input: 4 / \ 2 7 / \ / \ 1 3 6 9 Output: 4 / \ 7 2 / \ / \ 9 6 3 1 /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ class Solution { public TreeNode invertTree(TreeNode root) { TreeNode node = root; getInvertedNode(node); return node; } public void getInvertedNode(TreeNode node) { if(node != null){ if(node.left != null || node.right != null){ TreeNode temp = node.left; node.left = node.right; node.right = temp; } TreeNode left = node.left; TreeNode right = node.right; if(left != null) getInvertedNode(left); if(right != null) getInvertedNode(right); } } }