【二叉树】226.翻转二叉树

题目

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