二叉树

https://leetcode-cn.com/problems/same-tree/
看完题目就感觉用递归最简单粗暴。搞明白二叉树的构造应该就容易了。

# 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: TreeNode, q: TreeNode) -> bool:
        if not p and not q:
            return True
        if not p or not q:
            return False
        if p.val !=q.val:
            return False
        return self.isSameTree(p.left,q.left) and self.isSameTree(p.right,q.right)