Henning,
i need the bi-partitions of a multiset. That is, all the ways you can split
a multiset, M, into two multisets, M1 and M2, such that M = M1
`multiset-union` M2.
Best wishes,
--greg
On 5/23/07, Henning Thielemann
On Tue, 22 May 2007, Greg Meredith wrote:
mSplitC :: [a] -> [([a], [a])] -- C for comprehension
mSplitC [] = [([],[])] mSplitC [x] = [([x],[])] mSplitC (x:xs) = concat [ [(x:l,r),(l,x:r)] | (l,r) <- mSplitC xs ]
which Matthias Radestock suggested to me.
Note that if you only supply the empty multiset case, then you end up with duplicates.
That is ([1,2],[3]) and ([3],[1,2]) are considered the same? But you need always pairs not only [1,2] and [3] ?
-- L.G. Meredith Managing Partner Biosimilarity LLC 505 N 72nd St Seattle, WA 98103 +1 206.650.3740 http://biosimilarity.blogspot.com