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.
Β
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
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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 dfs(p, q):
            if not p and not q: return True
            if not p or not q: return False
 
            return p.val == q.val and dfs(p.left, q.left) and dfs(p.right, q.right)
        
        return dfs(p, q)