px = input('Enter Message Polynomial: ')

gx = input('Enter Generator Polynomial: ')

to_append = len(gx) - 1

original_px = px

for i in range(to_append):

px = '{0}0'.format(px)

def filter_px(px):

"""

This function is used to remove the zero from the MSB bit.

:param px: unfiltered polynomial

:return: filtered polynomial

"""

if px[0] == '0':

return px[1:]

def binary_division(px, gx):

"""

This function divides two polynomial using binary operations

:param px: Dividend polynimial

:param gx: Divisor polynomial

:return: Remainder polynimial

"""

while len(px) >= len(gx):

while px[0] == '0':

px = filter_px(px)

if len(px) < len(gx):

return px

for i in range(0, len(gx)):

if gx[i] == px[i]:

s = list(px)

s[i] = '0'

px = "".join(s)

else:

s = list(px)

s[i] = '1'

px = "".join(s)

return px

crc = binary_division(px, gx)

print("CRC code: ", crc)

new_px = original_px + crc

print("New px: ", new_px)

remainder = binary_division(new_px, gx)

print("Remainder: ", remainder)