poly py

class Polynomial:
  
  def __init__(self, coefficient, exponent, next = None):
    self.coefficient = coefficient
    self.exponent = exponent
    self.next = next

  def _add(term_a, term_b):
    if term_a == None:
      return term_b

    if term_b == None:
      return term_a

    if term_a.exponent == term_b.exponent:
      return Polynomial(
        term_a.coefficient + term_b.coefficient,
        term_a.exponent,
        Polynomial._add(term_a.next, term_b.next)
      )
    
    if term_a.exponent > term_b.exponent:
      return Polynomial(
        term_a.coefficient,
        term_a.exponent,
        Polynomial._add(term_a.next, term_b)
      )

    return Polynomial(
      term_b.coefficient,
      term_b.exponent,
      Polynomial._add(term_b.next, term_a)
    )

  def __add__(self, other):
    return Polynomial._add(self, other)

  def __str__(self):
    if self.next == None:
      next_str = ''
    else:
      next_str = str(self.next)
    return ' + ' + str(self.coefficient) + 'x^' + str(self.exponent) + next_str

# 3x^3 + 2x^2
term_3x3_2x2 = Polynomial(3, 3, Polynomial(2, 2))

# 3x^2 + 5x^0
term_3x2_5x0 = Polynomial(3, 2, Polynomial(5, 0))

new_term = term_3x3_2x2 + term_3x2_5x0
print(new_term)