input: Write a python function that determines the type of a triangle given a 0-indexed integer array sides of size 3 representing the lengths of its sides. The function should return "equilateral" if all the sides are equal, "isosceles" if exactly two sides are equal, "scalene" if all sides have different lengths, and "none" if the sides do not form a valid triangle.
  
  Examples:
  >>> sides = [2, 2, 2]
  "equilateral"
  >>> sides = [2, 3, 4]
  "scalene"
  
  Constraints:
  sides.length == 3
  1 <= sides[i] <= 100
output: def triangle_type(sides):
      a, b, c = sorted(sides)
      if a + b <= c:
          return "none"
      if a == b == c:
          return "equilateral"
      if a == b or b == c:
          return "isosceles"
      return "scalene"