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


    def isSubtree(self, root, subRoot) -> bool:
        if not subRoot:
            return True
        if not root:
            return False
        if self.isSameTree(root, subRoot):
            return True
        return self.isSubtree(root.left, subRoot) or self.isSubtree(root.right, subRoot)