leetcode100. 相同的树

https://leetcode-cn.com/problems/same-tree/

给定两个二叉树，编写一个函数来检验它们是否相同。
如果两个树在结构上相同，并且节点具有相同的值，则认为它们是相同的。

很简单：

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution:
    def isSameTree(self, p, q):
        """
        :type p: TreeNode
        :type q: TreeNode
        :rtype: bool
        """
        if not p and not q:
            return True
        if p and q and p.val == q.val:
            return self.isSameTree(p.left, q.left) and\
                   self.isSameTree(p.right, q.right)
        else:
            return False