pythagorean-triplets: declare type and add explicit args

Author: lpalma

exercises/pythagorean-triplet/src/Triplet.hs

@@ -1,7 +1,10 @@
 module Triplet (isPythagorean, mkTriplet, pythagoreanTriplets) where
 
-isPythagorean = error "You need to implement this function."
+isPythagorean :: (Int, Int, Int) -> Bool
+isPythagorean triplet = error "You need to implement this function."
 
-mkTriplet = error "You need to implement this function."
+mkTriplet :: Int -> Int -> Int -> (Int, Int, Int)
+mkTriplet a b c = error "You need to implement this function."
 
-pythagoreanTriplets = error "You need to implement this function."
+pythagoreanTriplets :: Int -> Int -> [(Int, Int, Int)]
+pythagoreanTriplets minFactor maxFactor = error "You need to implement this function."