Declaratieve Talen/Oplossing haskell nqueens

Mogelijke oplossing

nqueens::Int->[Int] ------------------- nqueens n = let list = [1..n] permlist = perms list in getoklist permlist getoklist::[[Int]]->[Int] ------------------------ getoklist [] = error "geen oplossing" getoklist (x:xs) | listok x = x | otherwise = getoklist xs listok::[Int]->Bool ------------------- listok [] = True listok (a:as) = if (listok2 a as 1) == False then False else listok as listok2::Int->[Int]->Int->Bool ------------------------------ listok2 _ [] _ = True listok2 a (b:bs) kol | a == (b+kol) = False | a == (b-kol) = False | otherwise = listok2 a bs (kol+1) --Permuteer de lijst perms :: [k] -> [[k]] --------------------- perms [] = [[]] perms (x:xs) = concat (map (tussen x) (perms xs)) where tussen e [] = [[e]] tussen e (y:ys) = (e:y:ys) : map (y:) (tussen e ys)