[LeetCode]题解（python）：100-Same Tree

题目来源：

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

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题意分析：

　　判断两棵树是否相等。

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题目思路：

　　用递归的思想，先判断根节点，再判断左右子树。

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代码（python）：

　　

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

class Solution(object):
    def isSameTree(self, p, q):
        """
        :type p: TreeNode
        :type q: TreeNode
        :rtype: bool
        """
        if p == None:
            return q == None
        if q == None:
            return p == None
        if p.val != q.val:
            return False
        else:
            return self.isSameTree(p.left,q.left) and self.isSameTree(p.right,q.right)