message: Update find-distance-in-a-binary-tree.py
diff: @@ -57,12 +57,12 @@ class Solution2(object):
  :type q: int
  :rtype: int
  """
  - def dfs(root, p, q, result):
  - if not root:
  + def dfs(node, p, q, result):
  + if not node:
  return -1
  - left = dfs(root.left, p, q, result)
  - right = dfs(root.right, p, q, result)
  - if root.val in (p, q):
  + left = dfs(node.left, p, q, result)
  + right = dfs(node.right, p, q, result)
  + if node.val in (p, q):
  if left == right == -1:
  return 0
  result[0] = left+1 if left != -1 else right+1
  