100. Same Tree

Python

# 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 __init__(self):
        self.is_same = True
        
    def isSameTree(self, p: Optional[TreeNode], q: Optional[TreeNode]) -> bool:
        self.checkSame(p, q)
        return self.is_same
    
    def checkSame(self, q, p):
        if q == None and p == None:
            return
        
        if (q == None and p != None) or (q != None and p == None):
            self.is_same = False
            return
        
        if q.val != p.val:
            self.is_same = False
            return
        
        self.checkSame(q.left, p.left)
        self.checkSame(q.right, p.right)