# 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):
def hasPathSum(self, root, sum):
"""
:type root: TreeNode
:type sum: int
:rtype: bool
"""
if root is None:
return False
sum = sum - root.val
if sum == 0 and root.left is None and root.right is None:
return True
# check left
left = self.hasPathSum(root.left, sum)
# check right
right = self.hasPathSum(root.right, sum)
return (left or right)
