Invert Binary Tree

题目链接地址

// Definition for a binary tree node.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;    temp = root.left;    root.left = root.right;    root.right = temp;    invertTree(root.left);    invertTree(root.right);    }return root;            }}