【leetcode❤python】 112. Path Sum

#-*- coding: UTF-8 -*-
# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution(object):
    sumList=[]
    def dfs(self,root):
        curSum=self.sumList[-1]
        
        if root.left!=None or root.right!=None:self.sumList.pop()
        else:return
        
        if root.left!=None:
            valsum=curSum+root.left.val
            self.sumList.append(valsum)
            self.dfs(root.left)
        if root.right!=None:
            valsum=curSum+root.right.val
            self.sumList.append(valsum)
            self.dfs(root.right)
   
    def hasPathSum(self, root, sum):
        """
        :type root: TreeNode
        :type sum: int
        :rtype: bool
        """
        self.sumList=[]
        if root==None:return False
        else:
            self.sumList.append(root.val)
            self.dfs(root)
            if self.sumList.__contains__(sum):
                return True
        return False