Answer to Question #243522 in Python for Rishi

Question

Give two polynomials A and B write a program that adds the given two polynomials A and B

Answer 1

def tostring_polynom(p):
  res = ''
  first = True
  for Pi in sorted(p, reverse=True):
    Ci = p[Pi]
    if first:
      if Ci == 0 and Pi == 0:
        return '0'
       
      if Ci == 1 and Pi != 0:
        pass
      elif Ci == -1 and Pi != 0:
        res = '-'
      else:      
        res = f'{Ci}'
      first = False
       
    else:     
      if Ci > 0:
        res += ' + '
      elif Ci < 0:
        res += ' - '
      else:
        continue
      res += f'{abs(Ci)}'
     
    if Pi == 0:
      continue
    if Pi == 1:
      res += 'x'
    else:
      res += f'x^{Pi}'
  return res
def read_polynom():
  n = int(input())
  p = {}
  for i in range(n):
    L = input().split()
    Pi = int(L[0])
    Ci = int(L[1])
    p[Pi] = Ci
  return p

def add_polynomilas(p,q):
  final_dict = {}
  if len(p) >= len(q):
    for k,v in p.items():
      final_dict[k] = v + q.get(k,0)
    final_keys = list(final_dict.keys())
    for k1,v1 in q.items():
      if k1 not in final_keys:
        final_dict[k1] = v1
  else:
    for k,v in q.items():
      final_dict[k] = v + p.get(k,0)
    final_keys = list(final_dict.keys())
    for k1,v1 in p.items():
      if k1 not in final_keys:
        final_dict[k1] = v1
  return final_dict
     

def main():
  p = read_polynom()
  q = read_polynom()
  r = add_polynomilas(p, q)
  print(f'Add {tostring_polynom(p)} to {tostring_polynom(q)}')
  print(f'results {tostring_polynom(r)}')
   

if __name__ == '__main__':
  main()

Test Case

If M = 4 and for polynomial A

For power 0, co-efficient is 5

For power 1, co-efficient is 0

For power 2, co-efficient is 10

For power 3, co-efficient is 6.

If N = 3 and for polynomial B

For power 0, co-efficient is 1

For power 1, co-efficient is 2

For power 2, co-efficient is 4.

Then polynomial A represents "6x^3 + 10x^2 + 5", the polynomial B represents "4x^2 + 2x + 1" and the addition of A and B is "6x^3 + 14x^2 + 2x + 6"