comefrom: <doocs>1740.Find Distance in a Binary Tree_2.py
code: def lca(root, p, q):
      if root is None or root.val in [p, q]:
          return root
      left = lca(root.left, p, q)
      right = lca(root.right, p, q)
      if left is None:
          return right
      if right is None:
          return left
      return root
masked: def sample_funcname ( var_1 , var_2 , var_3 ) :
      if var_1 is None or var_1.val in [ var_2 , var_3 ] :
          return var_1
      left = var_0 ( var_1.left , var_2 , var_3 )
      right = var_0 ( var_1.right , var_2 , var_3 )
      if left is None :
          return right
      if right is None :
          return left
      return var_1
  