Add prime number for lagrange

polynomial.py

@@ -147,11 +147,12 @@ def compute_lagrange_polynomial(points, prime_number):
                 poly_li *= dividend
                 divider *= (points[i][0] - points[k][0])
 
-        divider = 1 / divider
+        divider = modular_inverse(divider, prime_number)
         point_yi = points[i][1]
         poly_li = poly_li * Polynomial((divider,)) * Polynomial((point_yi,))
 
         lagrange += poly_li
+        lagrange %= prime_number
 
     return lagrange