Greatest common divisor: Difference between revisions

=={{header|Haskell}}==

That is already available as the function ''gcd'' in the Prelude. Here's the implementation:

gcd :: (Integral a) => a -> a -> a

gcd 0 0 = error "Prelude.gcd: gcd 0 0 is undefined"

gcd x y = gcd' (abs x) (abs y) where

gcd' a 0 = a

gcd' a b = gcd' b (a `rem` b)