4/10/2017 - 3:29 PM

## 124-Binary-Tree-Maximum-Path-Sum https://leetcode.com/problems/binary-tree-maximum-path-sum/

``````# 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 maxPathSum(self, root):
"""
:type root: TreeNode
:rtype: int
"""
self.maxSum =- float('inf')
self.findMax(root)
return self.maxSum

def findMax(self, root):
if root == None:
return 0
maxLeft = self.findMax(root.left)
maxRight = self.findMax(root.right)
self.maxSum = max(maxRight+maxLeft+root.val, self.maxSum)
return max(0, root.val, root.val+maxLeft, root.val+maxRight)``````

Given a binary tree, find the maximum path sum.

For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path must contain at least one node and does not need to go through the root.

For example: Given the below binary tree,

``````       1
/ \
2   3
``````

Return `6`.