comefrom: <doocs>0123.Best Time to Buy and Sell Stock III_1.py
code: def maxProfit( prices: List[int]) -> int:
      f1, f2, f3, f4 = -prices[0], 0, -prices[0], 0
      for price in prices[1:]:
          f1 = max(f1, -price)
          f2 = max(f2, f1 + price)
          f3 = max(f3, f2 - price)
          f4 = max(f4, f3 + price)
      return f4
masked: def sample_funcname ( var_0 : List [ int ] ) -> int :
      var_4 , var_5 , var_6 , var_7 = - var_0 [ 0 ] , 0 , - var_0 [ 0 ] , 0
      for var_9 in var_0 [ 1 : ] :
          var_4 = max ( var_4 , - var_9 )
          var_5 = max ( var_5 , var_4 + var_9 )
          var_6 = max ( var_6 , var_5 - var_9 )
          var_7 = max ( var_7 , var_6 + var_9 )
      return var_7
  