from fractions import gcd class Polynomial(): def __init__(self, lst, mod): self.poly = list(map(lambda x: x % mod, lst)) self.mod = mod self.normalize() def normalize(self): while self.poly and self.poly[-1] == 0: self.poly.pop() #zwraca jednomian stopnia n @staticmethod def Monomial(n, c, mod): zeros = [0]*n zeros.append(c) return Polynomial(zeros, mod) def __add__(self, p2): p1 = self len_p1, len_p2= len(p1.poly), len(p2.poly) res = [0] * max(len_p1, len_p2) if len_p1 > len_p2: for _ in range(len_p1-len_p2): p2.poly.append(0) else: for _ in range(len_p2-len_p1): p1.poly.append(0) for i in range(len(res)): res[i] = (p1.poly[i] + p2.poly[i]) % self.mod return Polynomial(res, self.mod) def __sub__(self, p2): p1 = self res = [] len_p2 = len(p2.poly) for i in range(len(p1.poly)): if i < len_p2: res.append(p1.poly[i] - p2.poly[i] % self.mod) else: res.append(p1.poly[i]) return Polynomial(res, self.mod) def __mul__(self, p2): res = [0]*(len(self.poly)+len(p2.poly)-1) for i, x1 in enumerate(self.poly): for j, x2 in enumerate(p2.poly): res[i+j] += x1 * x2 % self.mod return Polynomial(res, self.mod) def __eq__(self, p2): p1 = self return p1.poly == p2.poly and p1.mod == p2.mod def __pow__(self, n): p1 = self for i in range(n): p1 = p1 * p1 return p1 def __truediv__(self, p2): p1 = self m = self.mod if len(p1.poly) < len(p2.poly): return p1 if len(p2.poly) == 0: raise ZeroDivisionError divisor_coeff = p2.poly[-1] divisor_exp = len(p2.poly) - 1 while len(p1.poly) >= len(p2.poly): max_coeff_p1 = p1.poly[-1] #wspolczynnik przy najwyzszej potedze try: tmp_coeff = modDiv(max_coeff_p1, divisor_coeff, m) except ZeroDivisionError as e: raise e tmp_exp = len(p1.poly)-1 - divisor_exp tmp = [0] * tmp_exp tmp.append(tmp_coeff) sub = Polynomial(tmp, m) * p2 p1 = p1 - sub p1.normalize() return Polynomial(p1.poly, m) def poly_gcd(self, p2): p1 = self try: divisible = p2 except ZeroDivisionError as e: raise e if p2.poly == []: return p1 return p2.poly_gcd(p1 / p2) def modDiv(a, b, m): # a*b^-1 (mod m) if gcd(b, m) != 1: raise ZeroDivisionError else: return (a * modinv(b, m)) % m #rozszerzony algorytm euklidesa def egcd(a, b): if a == 0: return (b, 0, 1) else: g, y, x = egcd(b % a, a) return (g, x - (b // a) * y, y) def modinv(a, m): g, x, y = egcd(a, m) return x % m