Project Euler : Problem 39

dailycoding39.hs

-- Project Euler : Problem 39

import Data.List

rectTriangle :: Int -> [Int]
rectTriangle n = [a + b + c | a <- [1..(n - 2)], b <- [1..(a - 1)],
                              c <- [1..(b-1)], a^2 == b^2 + c^2,
                              a + b + c <= n]

main = print $ snd $ maximum $ map (\x -> (length x, head x)) $ group $
       sort $ rectTriangle 1000

-- 840
-- ./dailycoding39  187.38s user 0.47s system 99% cpu 3:08.78 total