'''
Description: 
Autor: Au3C2
Date: 2021-03-16 12:18:35
LastEditors: Au3C2
LastEditTime: 2021-03-16 12:19:25
'''
# 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 pathSum(self, root: TreeNode, targetSum: int) -> List[List[int]]:
        self.res = list()
        t = list()
        self.path_sum(root,targetSum,t)
        return self.res
    def path_sum(self,root,targetSum,t):
        if not root:
            return
        else:
            t.append(root.val)
        if not root.left and not root.right:
            if sum(t) == targetSum:
                self.res.append(list(t))
                
        if not self.path_sum(root.left,targetSum,t) and not self.path_sum(root.right,targetSum,t):
            t.pop()

# 树，中等，注意 self.res.append(list(t)) 很细节，没有list()的话，这题就不对了
# https://leetcode-cn.com/problems/path-sum-ii/