On Sun, Apr 10, 2011 at 12:49 PM, Anwar Bari
HI Cafe I have to make a function to check that I have one occurrence of the last element (z) of the same list [a,b] in the tuple
[([a,b],z)] For example [([1,2],3),([1,1],5),([1,3],6).......] this is true because there is one single z for each single list.
while this one is false [([1,2],3),([1,2],5),([1,3],6).......] because 3&5 were found for the same list [1,2]
any Idea how to code this Fn. Thanks
This seems to work... import Data.List a = [([1,2],3),([1,1],5),([1,3],6)] b = [([1,2],3),([1,2],5),([1,3],6)] test :: Ord a => [([a], a)] -> Bool test = not . hasDuplicates . sort where hasDuplicates [] = False hasDuplicates [_] = False hasDuplicates (x:xs) = fst x == fst (head xs) || hasDuplicates xs main = do print $ test a print $ test b Rob