【题目描述】
【源代码】
class Solution(object): def maxPathSum(self, root): """ :type root: TreeNode :rtype: int """ self.res = float('-inf') self.dfs(root) return self.res def dfs(self, root): if not root: return 0 #print '执行dfs(',root.val,')' left = max(0, self.dfs(root.left)) right = max(0, self.dfs(root.right)) #print 'self.res',left + root.val + right self.res = max(self.res, left + root.val + right) #print '返回给上层的是',root.val + max(left, right) return root.val + max(left, right) 复制代码