comefrom: <doocs>2090.K Radius Subarray Averages_1.py
code: def getAverages( nums: List[int], k: int) -> List[int]:
      n = len(nums)
      presum = [0] * (n + 1)
      for i in range(n):
          presum[i + 1] = presum[i] + nums[i]
      return [
          -1
          if i - k < 0 or i + k >= n
          else (presum[i + k + 1] - presum[i - k]) // (k * 2 + 1)
          for i in range(n)
      ]
masked: def sample_funcname ( var_0 : List [ int ] , var_3 : int ) -> List [ int ] :
      var_5 = len ( var_0 )
      var_8 = [ 0 ] * ( var_5 + 1 )
      for var_10 in range ( var_5 ) :
          var_8 [ var_10 + 1 ] = var_8 [ var_10 ] + var_0 [ var_10 ]
      return [ - 1 if var_10 - var_3 < 0 or var_10 + var_3 >= var_5 else ( var_8 [ var_10 + var_3 + 1 ] - var_8 [ var_10 - var_3 ] ) // ( var_3 * 2 + 1 ) for var_10 in range ( var_5 ) ]
  