Leetcode 429. N-ary Tree Level Order Traversal

bfs

class Solution:
    def levelOrder(self, root: 'Node') -> List[List[int]]:
        q,ans=[root],[]
        while q and q[0]:
            ans.append([node.val for node in q])
            q=[child for node in q for child in node.children if child]
        return ans