429. N-ary Tree Level Order Traversal

https://leetcode.com/problems/n-ary-tree-level-order-traversal/

Python

DFS

class Solution:
    def levelOrder(self, root: 'Node') -> List[List[int]]:
        def dfs(node, level, result):
            if not node:
                return

            if len(result) <= level:
                result.append([])

            result[level].append(node.val)

            for child in node.children:
                dfs(child, level+1, result)

        levels = []
        dfs(root, 0, levels)
        return levels