Given a non-empty 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.
Example 1:
Input: [1,2,3]
1
/ \
2 3
Output: 6
Example 2:
Input: [-10,9,20,null,null,15,7]
-10
/ \
9 20
/ \
15 7
Output: 42
My code:
# 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
"""
def maxend(node):
if not node:
return 0
left = maxend(node.left)
right = maxend(node.right)
self.max = max(self.max, left + node.val + right)#Here we have child best result
return max(node.val + max(left, right), 0)
self.max = None
maxend(root)
return self.max
Solution: https://leetcode.com/problems/binary-tree-maximum-path-sum/