leetcode-226 翻转二叉树

题目描述：翻转一棵二叉树。

代码实现

递归实现

class Solution {
    public TreeNode invertTree(TreeNode root) {
        if (root == null || (root.left == null && root.right == null)){
            return root;
        }
        TreeNode node = invertTree(root.left);
        root.left = invertTree(root.right);
        root.right = node;
        return root;
    }
}