my code below seem to work well if either number's length is even, but if both length of number are odd(like in the pic), it outputs the wrong result. I have no idea where it went wrong or how to fix it.
def karatsubaMulti(num1, num2):
len1 = len(str(num1))
len2 = len(str(num2))
if len1==1 or len2==1:
return num1*num2
else:
maxLen = max(len1, len2)
if maxLen > len1:
a=0
b=num1
else:
a = num1 // pow(10, maxLen//2)
b = num1 % pow(10, maxLen//2)
if maxLen > len2:
c=0
d=num2
else:
c = num2 // pow(10, maxLen//2)
d = num2 % pow(10, maxLen//2)
z1 = karatsubaMulti(a, c)
z2 = karatsubaMulti(b, d)
z3 = karatsubaMulti(a+b, c+d)
return z1 * pow(10, maxLen) + (z3-z1-z2) * pow(10, maxLen//2) + z2
x = 171
y = 571
xy1 = karatsubaMulti(x, y)
print(xy1)
