xea.py

# usage: python xea.py <num1> <num2>

from sys import argv

pa, pb = int(argv[1]), int(argv[2])

a, b = pa, pb

mods = [a, b]

mod = a % b
while mod != 0:
    mods.append(mod)
    a = b
    b = mod
    mod = a % b

xi = [1, 0]
yi = [0, 1]
for i in range(2, len(mods)):
    xi.append(xi[i - 2] - (xi[i - 1] * int(mods[i - 2] / mods[i - 1])))
    yi.append(yi[i - 2] - (yi[i - 1] * int(mods[i - 2] / mods[i - 1])))
    

print("ri =", mods)
print("xi =", xi)
print("yi =", yi)

print(xi[-1], "*", pa, "+", yi[-1], "*", pb, "=", end=" ")
print("gcd(" + str(pa) + ", " + str(pb) + ") = " + str(mods[-1]))