I do not need the unique constraint.
Description fixed.

Given an array of unique ints, …

Actually, your static example #1 contains 4 two times. And the "random lists" does so too. Both those things are fixable, but do your really need lists of unique ints?

Fixed
Thanks

The initial solution still has Oldest as module name:

Maybe there's some caching which prevents your changes?

Module name was Ok.
Removed Test.Quickcheck from example test cases
Corrected type of my solution and user's one.
Included your Quickcheck random test (Thanks!)

The initial solution has a wrong module name Oldest instead of SumUpNoAdjacents. Also, your example test cases include Test.QuickCheck, but don't actually use QuickCheck.

Your test cases include both Data.List and Test.QuickCheck but use neither, although your solution is included. Probably because QuickCheck timed out, right? You can resize the size of a generated value:

    it "should work on random lists" $ 
      property $ 
        forAll (resize 20 arbitrary) $ \xs ->
        forAll arbitrary             $ \x  ->
          sumUpNoAdjacents xs x `shouldBe` solution xs (x :: Integer)

That way the list won't be too large, and the computation won't time out.

Also, your solution and the user's solution differ in their type: While you use [Int] -> Int -> Bool, the user has to write (Num a, Eq a) => [a] -> a -> Bool.

Module name: fixed
"it" was just bad indented
Thanks

Module needs to remained, and the test doesn't compile. (Uses "it" name which isn't defined.)

A fair point, but I'm sure people are clear as to what I'm meaning.

Err..Sorry I was speaking about the haskell version.

the [a] datatype in haskell is called a list (because it /is/ a linked list).

There are arrays in Data.Array and its sub modules.

I doubt any 'bad' solutions could pass the test case for an array of length 500!

There is only one "good" solution here. In my opinion, you should not suggest bad ones...

This is not true. In python, your statement is acceptable, but in all other implemented languages 'list' doesn't exist.

It takes an list not an array.