2023.6.12
二叉树是先加左节点再加右节点，n叉树是一个循环把所有节点加到队列尾部
"""
# Definition for a Node.
class Node:def __init__(self, val=None, children=None):self.val = valself.children = children
"""class Solution:def levelOrder(self, root: 'Node') -> List[List[int]]:if not root:return []queue = collections.deque()queue.append(root)res = []while queue:level = []for _ in range(len(queue)):node = queue.popleft()level.append(node.val)for i in node.children:queue.append(i)res.append(level)return res
