687. Longest Univalue Path

class TreeNode: def __init__(self, x): self.val = x self.left = None self.right = None class Solution: def longestUnivaluePath(self, root): if root == None: return 0 def longestHelper(self, root): # this function returns both the value and whether include_root = True if root == None: val = 0 include_root = False return [val, include_root] elif (root.left == None and root.right == None): # leaf node val = 1 include_root = True return [val, include_root] else: if root.val == root.left.val: # current node val = left child val if longestHelper(root.left)[1] == True: lmax = longestHelper(root.left)[0] + 1 linclude = True else: lmax = longestHelper(root.left)[0] linclude = False else: