Archived from groups: comp.ai.games (
More info?)
AngleWyrm wrote:
> "googleartist" <googleartist@yahoo.com> wrote in message
> news:1102710218.179922.301340@c13g2000cwb.googlegroups.com...
> <in previous posts>
>
>>I am looking for algorithm by which I can have smaller fixed number of
>>element which gives a unique identity for that set.
>>example: I have
>>A = { 2,4,6,8}
>>B = { 3,6,9,12}
>>C = { 4,8,12,16}
>
>
>>and I like to take minumum 2 element
>>I can have
>>A* = { 2,4}
>>B* = {3,9}
>>C* = {12,16}
>
> <end previous posts>
>
>>4 is not unique to A, but {2,4} represents a 2-item ID for "A'" which
>>sets it apart from 'C' which has id: {12,16}. Since the requirement is
>>'2', you have to provide atleast 2items if possible for providing
>>unique ID.
>
>
> Looks like a database problem, identifying unique key. I have one more question
> about this situation. If I make a set of three answers like so:
> A' = {2}
> B' = {3}
> C' = {16}
> They seem to characterize their sets uniquely, and identify a width of one
> rather than two. In your example, you drew C* from different "columns",
> suggesting that the items are not sorted, or arranged in record fields.
>
> Q: Are that the answers {A*, B*, C*} of width two more fitting than the answers
> {A', B', C'} of width one, and if so then why/how?
>
> -:|:-
> AngleWyrm
>
>
judging from the replys have a look for 3-Hitting Set. I know there are
paramterised complexity algorithms for it that have been developed by
fellows and co. www.cs.newcastle.edu.au/~fellows/ should give you a start.