16 Oct
2008
16 Oct
'08
5:39 a.m.
2008/10/16 John Ky
Hi,
I've written this function here:
scramble [] = [] scramble [x] = [[z] | z <- scramble x] scramble (x:xs) = [(y:z)|y <- scramble x, z <- scramble xs]
and (I think) it roughly does what I want it to:
*Main> scramble ([]::[Int]) [] *Main> scramble ([1]::[Int]) [[1],[2]]
So, um, this is nonsense. You've given it only 1, and yet it outputs a 2, yet there is no mention of addition or the literal 2 anywhere in your function. This function looks a lot like the more sensible: scramble' n xs = sequence (replicate n xs)
scramble' 0 [1,2,3] [[]] scramble' 1 [1,2,3] [[1],[2],[3]] scramble' 2 [1,2,3] [[1,1],[1,2],[1,3],[2,1],[2,2],[2,3],[3,1],[3,2],[3,3]]
Where your examples all had [1,2] as the argument. Luke