def bm(s):
print("BM:")
p = s[0].p
field = get_field_elements(p)
l = 0
loc = Poly([one(p)])
b = Poly([one(p)])
for r in range(1, len(s) + 1):
b.l = [zero(p)] + b.l
d = calc_d(loc, s, l, r)
if d != zero(p):
t = loc + b.factor(d)
if 2 * l <= r - 1:
b = loc.factor(d.inverse())
l = r - l
loc = t
print("Step %d:" % r)
sys.stdout.write("\tΔ = ")
if d == zero(p):
print(0)
elif d == one(p):
print(1)
else:
print("a" + to_superscript(field.index(d)))
print("\tΛ(x) = " + gal_poly_str(loc, field))
print("\tL = %d" % l)
print("\tB(x) = " + gal_poly_str(b, field))
print()
if len(loc.l) - 1 == l:
return loc
else:
return None
def calc_d(loc, s, l, r):
p = s[0].p
d = zero(p)
for j in range(l + 1):
d += loc.l[j] * s[r - j - 1]
return d
