Given the root of a binary tree, invert the tree, and return its root.
Example 1
Input: root = [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() {} * TreeNode(int val) { this.val = val; } * TreeNode(int val, TreeNode left, TreeNode right) { * this.val = val; * this.left = left; * this.right = right; * } * } */ class Solution { public TreeNode invertTree(TreeNode root) { if(root==null){ return null; } TreeNode tmp=root.left; root.left=root.right; root.right=tmp; invertTree(root.left); invertTree(root.right); return root; } }