LC100_SameTree.py

# 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:
        # tree traversals, DFS
        # time complexity: O(p + q)

        if not p and not q:
            return True
        if not p or not q or p.val != q.val:
            return False
            
        return (self.isSameTree(p.left, q.left)) and (self.isSameTree(p.right, q.right))