题目：

题解：

class Solution:
    def isSameTree(self, p: TreeNode, q: TreeNode) -> bool:
        if not p and not q:
            return True
        if not p or not q:
            return False
        
        queue1 = collections.deque([p])
        queue2 = collections.deque([q])

        while queue1 and queue2:
            node1 = queue1.popleft()
            node2 = queue2.popleft()
            if node1.val != node2.val:
                return False
            left1, right1 = node1.left, node1.right
            left2, right2 = node2.left, node2.right
            if (not left1) ^ (not left2):
                return False
            if (not right1) ^ (not right2):
                return False
            if left1:
                queue1.append(left1)
            if right1:
                queue1.append(right1)
            if left2:
                queue2.append(left2)
            if right2:
                queue2.append(right2)

        return not queue1 and not queue2