From 2024fc272af5811c3c594bf08959af2c9f62371d Mon Sep 17 00:00:00 2001 From: jianghongcheng <35664721+jianghongcheng@users.noreply.github.com> Date: Mon, 22 May 2023 16:48:27 -0500 Subject: [PATCH] =?UTF-8?q?Update=200257.=E4=BA=8C=E5=8F=89=E6=A0=91?= =?UTF-8?q?=E7=9A=84=E6=89=80=E6=9C=89=E8=B7=AF=E5=BE=84.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0257.二叉树的所有路径.md | 40 ++++++++++------------- 1 file changed, 18 insertions(+), 22 deletions(-) diff --git a/problems/0257.二叉树的所有路径.md b/problems/0257.二叉树的所有路径.md index c396f4a0..4cafbded 100644 --- a/problems/0257.二叉树的所有路径.md +++ b/problems/0257.二叉树的所有路径.md @@ -473,31 +473,27 @@ class Solution { 递归法+回溯(版本一) ```Python # Definition for a binary tree node. -# class TreeNode: -# def __init__(self, val=0, left=None, right=None): -# self.val = val -# self.left = left -# self.right = right -import copy -from typing import List, Optional - class Solution: - def binaryTreePaths(self, root: Optional[TreeNode]) -> List[str]: - if not root: - return [] + def traversal(self, cur, path, result): + path.append(cur.val) # 中 + if not cur.left and not cur.right: # 到达叶子节点 + sPath = '->'.join(map(str, path)) + result.append(sPath) + return + if cur.left: # 左 + self.traversal(cur.left, path, result) + path.pop() # 回溯 + if cur.right: # 右 + self.traversal(cur.right, path, result) + path.pop() # 回溯 + + def binaryTreePaths(self, root): result = [] - self.generate_paths(root, [], result) + path = [] + if not root: + return result + self.traversal(root, path, result) return result - - def generate_paths(self, node: TreeNode, path: List[int], result: List[str]) -> None: - path.append(node.val) - if not node.left and not node.right: - result.append('->'.join(map(str, path))) - if node.left: - self.generate_paths(node.left, copy.copy(path), result) - if node.right: - self.generate_paths(node.right, copy.copy(path), result) - path.pop() ```