comefrom: <doocs>2265.Count Nodes Equal to Average of Subtree_1.py
code: def dfs(root):
      if root is None:
          return 0, 0
      ls, ln = dfs(root.left)
      rs, rn = dfs(root.right)
      s = ls + rs + root.val
      n = ln + rn + 1
      if s // n == root.val:
          nonlocal ans
          ans += 1
      return s, n
masked: def sample_funcname ( var_1 ) :
      if var_1 is None :
          return 0 , 0
      var_4 , var_6 = var_0 ( var_1.left )
      var_7 , var_9 = var_0 ( var_1.right )
      var_11 = var_4 + var_7 + var_1.val
      var_13 = var_6 + var_9 + 1
      if var_11 // var_13 == var_1.val :
          nonlocal var_14
          var_14 += 1
      return var_11 , var_13
  