same_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):
        if not p and not q:
            return True

        if (p and not q) or (not p and q):
            return False

        if p.val != q.val:
            return False

        return self.isSameTree(p.left, q.left) and self.isSameTree(p.right ,q.right)

        # Time Complexity: O(n)
        # Space Complexity: O(h)

    def isSameTree(self, p, q):
            stack = [(p, q)]
            while stack:
                p, q = stack.pop()

                if not p and not q:
                    continue

                if (p and not q) or (not p and q):
                    return False

                if p.val != q.val:
                    return False

                stack.append((p.left, q.left)) if p and q else None
                stack.append((p.right, q.right)) if p and q else None

            return True