29 lines
634 B
Haskell
29 lines
634 B
Haskell
module SoloveyStrassen (soloveyStrassen) where
|
|
|
|
import ModularArithmeticUtils (modExp, jacobi)
|
|
import System.Random (randomRIO)
|
|
|
|
|
|
soloveyStrassen :: Integer -> Integer -> IO Bool
|
|
soloveyStrassen n k
|
|
| n < 2 = return False
|
|
| n == 2 = return True
|
|
| even n = return False
|
|
| otherwise = go k
|
|
where
|
|
expHalf = (n - 1) `div` 2
|
|
|
|
go 0 = return True
|
|
go i = do
|
|
a <- randomRIO (2, n - 2)
|
|
if gcd a n /= 1
|
|
then return False
|
|
else do
|
|
let x = modExp a expHalf n
|
|
j = jacobi a n `mod` n
|
|
|
|
if x /= j
|
|
then return False
|
|
else go (i - 1)
|
|
|