Regarding finding the number of unique elements in a list.

Tom Bevan tom@regex.com.au
18 Jan 2002 10:31:17 +1100


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I consider myself a newbie too but here are my solutions


Tom

On Fri, 2002-01-18 at 10:14, Amrit K Patil ;012;VKSF6; wrote:
> 
> Hi,
> 
> I am newbie at Haskell.
> 
> I am not able to write a program to find the number of unique elments in a
> list in haskell.
> 
> I am also not able to write a porgram to find the elements in the
> innermost list in a list within lists.
> 
> Can anybody guide me as to g\how to go about it or better still send me
> the program.
> 
> It would be of great help.
> 
> Have a good day..
> 
> cheers,
> 
> amrit.
> 
> peace....
> 
> 
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--Function that returns true if
--an element in contained in the list
contains :: Eq a =3D> a -> [a] -> Bool

contains _ [] =3D False
contains a (x:xs) | a=3D=3Dx =3D True
		  | otherwise =3D contains a xs

--Function to remove all multiple
--occurences of elements in a list
unique :: Eq a =3D> [a] -> [a]

unique [] =3D []
unique (x:xs) | contains x xs =3D unique xs
	      | otherwise =3D x:unique xs

innerList :: [[a]] -> [a]

innerList =3D foldr (++) []

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