Re: All componens different
- To: mathgroup at smc.vnet.net
- Subject: [mg112001] Re: All componens different
- From: Helen Read <hpr at together.net>
- Date: Tue, 24 Aug 2010 06:13:07 -0400 (EDT)
- References: <i4t5qb$g2q$1@smc.vnet.net>
- Reply-to: read at cems.uvm.edu
On 8/23/2010 2:51 AM, Dr. Wolfgang Hintze wrote:
> Given a list v of natural numbers I'm looking for a function d[v_] that
> returns True if all components are different and False otherwise.
>
> One solution is
>
> d1[v_] := ! Or @@ Flatten[Table[v[[i]] == v[[k]], {i, 1, Length[v]},
> {k, i + 1, Length[v]}]]
>
> Can you find more efficient (and elegant) solutions?
>
> Regards,
> Wolfgang
d[v_] := Length[Union[v]] == Length[v]
--
Helen Read
University of Vermont