.二叉树的堂兄弟节点

示例 1：

输入：root = [1,2,3,4], x = 4, y = 3

输出：false

示例 2：

输入：root = [1,2,3,null,4,null,5], x = 5, y = 4

输出：true

示例 3：

输入：root = [1,2,3,null,4], x = 2, y = 3

输出：false

# Definition for a binary tree node.

# class TreeNode:

#     def __init__(self, val=0, left=None, right=None):

#         self.val = val

#         self.left = left

#         self.right = right

class Solution:

    def isCousins(self, root, x, y):

        result_x = []

        result_y = []

        def dfs(node,parent,deep):

            if not node:

                return

            nonlocal result_x, result_y

            if node.val == x:

                result_x = [parent,deep]

            elif node.val == y:

                result_y = [parent,deep]

            dfs(node.left,node,deep + 1)

            dfs(node.right,node,deep + 1)

        dfs(root,root,0)

        return result_x[0] != result_y[0] and result_x[1] == result_y[1]