LeeCode-Invert Binary Tree

Invert a binary tree.

     4   /   \  2     7 / \   / \1   3 6   9

to

     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; } * } */public class Solution {    public TreeNode invertTree(TreeNode root) {                        if(root!=null)          {        TreeNode temp  = root.left;          root.left = root.right;          root.right = temp;                    invertTree(root.left);          invertTree(root.right);                    return root;           }        return null;    }}