'''
Description: 
Autor: Au3C2
Date: 2021-03-18 16:22:15
LastEditors: Au3C2
LastEditTime: 2021-03-18 16:22:28
'''
# 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
class Solution:
    def binaryTreePaths(self, root: TreeNode) -> List[str]:
        self.path_list = list()
        t = list()
        self.recursion(root,t)
        res = list()
        for path in self.path_list:
            res.append('->'.join(path))
        return res
    def recursion(self,root,t):
        if not root:
            return 0
        else:
            t.append(str(root.val))
        if not root.left and not root.right:
            self.path_list.append(list(t))
        self.recursion(root.left,t)
        self.recursion(root.right,t)
        t.pop()

# 树，简单
# https://leetcode-cn.com/problems/binary-tree-paths/