LeetCode Algorithm 590. N 叉树的后序遍历

Posted 2022-03-28 Alex_996

590. N 叉树的后序遍历

Ideas

N叉树的后序遍历其实就是前序遍历翻转过来，所以我们可以用栈模拟递归得到前序遍历序列，然后翻转一下就OK了。

Code

Python

class Solution:
	def postorder(self, root: 'Node') -> List[int]:
		if root is None:
			return []
		
		stack, ans = [root], []
		while stack:
			node = stack.pop()
			if node is not None:
				ans.append(node.val)
			for item in node.children:
				stack.append(item)
		return ans[::-1]