题解 | #二叉树的镜像#

using System;
using System.Collections.Generic;

/*
public class TreeNode
{
    public int val;
    public TreeNode left;
    public TreeNode right;

    public TreeNode (int x)
    {
        val = x;
    }
}
*/

class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param pRoot TreeNode类
     * @return TreeNode类
     */
    public TreeNode Mirror (TreeNode pRoot) {
        // write code here
        if (pRoot == null)
            return null;
        TreeNode trL = Mirror(pRoot.left);
        TreeNode trR = Mirror(pRoot.right);
        pRoot.left = trR;
        pRoot.right = trL;
        return pRoot;
    }
}