二叉树的完全性检验

from collections import deque
class TreeNode:
    def __init__(____):
        self.val = val
        self.left = left
        self.right = right

def solve():
    def isCompleteTree(____):
        if not root:
            return True
        queue = deque(____)
        seen_null = False
        while queue:
            node = queue.popleft()
            if not node:
                seen_null = True
            else:
                if seen_null:
                    return False
                queue.append(____)
                queue.append(____)
        return True
    root = TreeNode(____, TreeNode(____, TreeNode(____), TreeNode(____)), TreeNode(____, TreeNode(____)))
    print(isCompleteTree(____))