Re: Help ! complex permutations
- To: mathgroup at smc.vnet.net
- Subject: [mg7045] Re: [mg6965] Help ! complex permutations
- From: "w.meeussen" <w.meeussen.vdmcc at vandemoortele.be>
- Date: Sat, 3 May 1997 22:04:39 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
At 22:25 30-04-97 -0400, Robert Perkins wrote:
>I need to derive an algorithm, formula, which gives all the
>possiblities, combinations, for any 'n' out of 'm' with the proviso
>that any member of 'm' can be used multiple times and the selection
>sequence is significant.
>
>Taking a trivial example if the input list 'm' is
>
> {a,b}
>
>the output list 'n' for any 2 gives
>
> {a,a},{a,b},{b,a},{b,b}
>
>For an output sequence of 3 from the same input list would give
>
> {a,a,a},{a,a,b},{a,b,b},{b,a,b},{b,b,a},{b,b,b}
>
>Life gets interesting for larger input sequences and ever larger
>output selections. How about the input list containing 10 members and
>the output list containing 20 members with the above rules applying?
>
>Can anyone point me in the right direction? A reference, clue or even
>an algorithm would be very welcome ;)
>
>TIA
>
>Robert_p
>
>
>
>
look at Outer[List,{a,b},{a,b},{a,b}]
Dr. Wouter L. J. MEEUSSEN
eu000949 at pophost.eunet.be
w.meeussen.vdmcc at vandemoortele.be