标签:not extend ext end pen stack init child node
DFS,递归或者栈实现.
""" # Definition for a Node. class Node: def __init__(self, val, children): self.val = val self.children = children """ class Solution: def postorder(self, root: ‘Node‘) -> List[int]: if not root: return [] if not root.children: return [root.val] ans=[] stack=[root] node=stack[-1] mark={} while stack: if (not node.children) or (mark.get(node.children[0],0)==1): pop=stack.pop() mark[pop]=1 ans.append(pop.val) if not stack: break node=stack[-1] else: stack.extend(reversed(node.children)) node = stack[-1] return ans
""" # Definition for a Node. class Node: def __init__(self, val, children): self.val = val self.children = children """ class Solution: def postorder(self, root: ‘Node‘) -> List[int]: if not root: return [] if not root.children: return [root.val] ans=[] for c in root.children: ans.extend(self.postorder(c)) return ans+[root.val]
Leetcode 590. N-ary Tree Postorder Traversal
标签:not extend ext end pen stack init child node
原文地址:https://www.cnblogs.com/zywscq/p/10741936.html