1 """
2 Given two binary trees, write a function to check if they are the same or not.
3 Two binary trees are considered the same if they are structurally identical and the nodes have the same value.
4 Example 1:
5 Input: 1 1
6 / \ / \
7 2 3 2 3
8 [1,2,3], [1,2,3]
9 Output: true
10 Example 2:
11 Input: 1 1
12 / \
13 2 2
14 [1,2], [1,null,2]
15 Output: false
16 Example 3:
17 Input: 1 1
18 / \ / \
19 2 1 1 2
20 [1,2,1], [1,1,2]
21 Output: false
22 """
23 class TreeNode:
24 def __init__(self, x):
25 self.val = x
26 self.left = None
27 self.right = None
28
29 class Solution:
30 def isSameTree(self, p: TreeNode, q: TreeNode) -> bool:
31 if p == None and q == None:
32 return True
33 # bug代码
34 # flag = False
35 # while p and q:
36 # if p.val == q.val:
37 # self.isSameTree(p.left, q.left)
38 # self.isSameTree(q.right, q.right)
39 # flag = True
40 # return flag
41 # 递归注意不用while循环，也应当注意return返回值
42 if p and q and p.val == q.val:
43 return self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)
