本帖已被设为精华帖！
给定一颗二叉树，找到最长连续路径的长度，即任何序列起始节点到树种任一节点都必须遵循父 - 子关系，最长的连续路径必须是从父节点到子节点
参考代码:
class TreeNode:
def __init__(self, val):
self.val = val
self.left = None
self.right = None
class Solution:
def longestConsecutive(self, root):
return self.helper(root, None, 0)
def helper(self, root, parent, len):
if root is None:
return len
if parent != None and root.val == parent.val + 1:
len += 1
else:
len = 1
return max(len, max(self.helper(root.left, root, len), self.helper(root.right, root, len)))