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# https://leetcode.com/problems/path-sum/

#

# Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum.

#

# For example:

# Given the below binary tree and sum = 22,

# 5

# / \

# 4 8

# / / \

# 11 13 4

# / \ \

# 7 2 1

# return true, as there exist a root-to-leaf path 5->4->11->2 which sum is 22.

# Definition for a binary tree node

# class TreeNode:

# def __init__(self, x):

# self.val = x

# self.left = None

# self.right = None

class Solution:

# @param root, a tree node

# @param sum, an integer

# @return a boolean

def hasPathSum(self, root, sum):

if root == None:

return False

elif root.left == None and root.right == None :

return root.val == sum

elif root.left == None:

return self.hasPathSum(root.right , sum - root.val)

elif root.right == None:

return self.hasPathSum(root.left , sum - root.val)

else:

return self.hasPathSum(root.left,sum -root.val) or self.hasPathSum(root.right , sum - root.val)