Description
Given the roots of two binary trees p
and q
, write a function to check if they are the same or not.
Two binary trees are considered the same if they are structurally identical, and the nodes have the same value.
Example 1:

Input: p = [1,2,3], q = [1,2,3] Output: true
Example 2:

Input: p = [1,2], q = [1,null,2] Output: false
Example 3:

Input: p = [1,2,1], q = [1,1,2] Output: false
Constraints:
- The number of nodes in both trees is in the range
[0, 100]
. -104 <= Node.val <= 104
Solution
Python3
# 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 isSameTree(self, p: Optional[TreeNode], q: Optional[TreeNode]) -> bool:
def same(node1, node2):
if not node1 and not node2: return True
if not node1 or not node2: return False
return node1.val == node2.val and same(node1.left, node2.left) and same(node1.right, node2.right)
return same(p, q)