input: Write a function that performs a linear scaling on a list of numbers such that the smallest number is mapped to 0 and the largest number is mapped to 1.
  assert scale_to_unit_interval([2.0, 49.9]) == [0.0, 1.0]
  assert scale_to_unit_interval([100.0, 49.9]) == [1.0, 0.0]
  assert scale_to_unit_interval([1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
  assert scale_to_unit_interval([2.0, 1.0, 5.0, 3.0, 4.0]) == [0.25, 0.0, 1.0, 0.5, 0.75]
  assert scale_to_unit_interval([12.0, 11.0, 15.0, 13.0, 14.0]) == [0.25, 0.0, 1.0, 0.5, 0.75]
output: def scale_to_unit_interval(lst):
      min_val = min(lst)
      max_val = max(lst)
      return [(x - min_val) / (max_val - min_val) for x in lst]