crc16.py

@@ -1,74 +1,8 @@
+from poly import Polynomial
 import sys
 import ast
 
-class Polynomial:
-
-    def __init__(self, coef_list):
-        self.degree = len(coef_list) - 1
-        self.coefficients = coef_list
-
-    @staticmethod
-    def add(p1, p2):
-        result = []
-        f = p1.coefficients
-        g = p2.coefficients
-        if len(f) >= len(g):
-            result = f
-            for i in range(0, len(g)):
-                result[i] = f[i] + g[i]
-        else:
-            result = g
-            for i in range(0, len(f)):
-                result[i] = f[i] + g[i]
-        result = [x % int(n) for x in result]        
-        return Polynomial(result)             
-
-    @staticmethod
-    def multiply(p1, p2):
-        result = [0] * (p1.degree + p2.degree + 1)
-        f = p1.coefficients
-        g = p2.coefficients
-        for i in range(0, len(f)):
-            for j in range(0, len(g)):
-                result[i+j] += f[i] * g[j]
-        result = [x % int(n) for x in result]
-        return Polynomial(result)
-
-    @staticmethod
-    def divide(p1, p2):          
-        def inverse(x):
-            for i in range(1, int(n)):
-                r = (i * x) % int(n)
-                if r == 1:
-                    break
-            else:
-                raise ZeroDivisionError
-            return i       
-        if p1.degree < p2.degree:
-            return p1
-        f = p1.coefficients
-        g = p2.coefficients
-        g_lead_coef = g[-1]
-        g_deg = p2.degree
-        while len(f) >= len(g):
-            f_lead_coef = f[-1]
-            tmp_coef = f_lead_coef * inverse(g_lead_coef)
-            tmp_exp = len(f) - 1 - g_deg
-            tmp = []
-            for _ in range(tmp_exp):
-                tmp.append(0)
-            tmp.append(tmp_coef)
-            tmp_poly = Polynomial(tmp)
-            sub = Polynomial.multiply(p2, tmp_poly)
-            f = [x - y for x, y in zip(f, sub.coefficients)]
-            f = [x % int(n) for x in f]
-            while f and f[-1] == 0:
-                f.pop()
-        return Polynomial(f)
-
-
-n = 2
-
+Polynomial.n = 2
 
 def normalize_byte(data):
     while len(data) != 8: