N-ary Tree Postorder Traversal

Problem Id: 590 Difficulty: Easy Tag: Tree


Intuition

Simple use post order traversal with an additional variable order. And when visiting a node, add the node's value to the order list.

Solution


"""
# Definition for a Node.
class Node:
    def __init__(self, val=None, children=None):
        self.val = val
        self.children = children
"""
class Solution:
    def postorder(self, root: 'Node') -> List[int]:
        order = []
        self._helper(root, order)
        return order

    def _helper(self, node, order):
        if node is None:
            return
        for child in node.children:
            self._helper(child, order)
        order.append(node.val)