Compute_lagrange fonctionnel

polynome.py

@@ -38,7 +38,7 @@ class polynome():
         coeff_poly_res = [0] * (len(self.coefs) + len(poly_2.coefs) - 1)
         for index_1, value_1 in enumerate(self.coefs):
             for index_2, value_2 in enumerate(poly_2.coefs):
-                coeff_poly_res[index_1 + index_2] += value_1 * value_2 % self.prime_mod
+                coeff_poly_res[index_1 + index_2] += (value_1 * value_2) % self.prime_mod
         return polynome(coeff_poly_res)
     
     def evaluate(self, x):
@@ -46,4 +46,4 @@ class polynome():
         res = 0
         for i in range(len(self.coefs) - 1, -1, -1):
             res = (res * x + self.coefs[i])
-        return res % self.prime_mod
+        return (res % self.prime_mod)

reed_solomon.py

@@ -29,12 +29,8 @@ def lagrange_compute(l: list) -> polynome:
 		poly_n = polynome([1])
 		for x_k, y_k in enumerate(l):
 			if x_k != x_i:
-				#print(f"value : {x_i - x_k}")
-				d = inverse_mult(x_i-x_k, poly_n.prime_mod)
-				#print(f"inverse : {d}")
-				#poly_n = poly_n.mul(polynome([-x_k / (x_i-x_k), 1 / (x_i-x_k)]))
+				d = inverse_mult((x_i-x_k) % poly_n.prime_mod, poly_n.prime_mod)
 				poly_n = poly_n.mul(polynome([-x_k * d % poly_n.prime_mod, d % poly_n.prime_mod]))
-				#poly_n.show()
 		poly_n = poly_n.mul(polynome([y_i[1] % poly_n.prime_mod]))
 		poly = poly.add(poly_n)
 	return poly
@@ -43,7 +39,7 @@ def check_nb_error(l: list, p: polynome) -> int:
 	pass
 
 if __name__ == '__main__':
-	list_ = [(0, 2), (1, 4), (2, 8)]
+	list_ = [(0, 0), (1, 1), (2, 2)]
 	poly = lagrange_compute(list_)
-	poly.show()
-	print(poly.evaluate(1))
+	#poly.show()
+	print(poly.evaluate(5))