Re: Super-Increasing List
- To: mathgroup at smc.vnet.net
- Subject: [mg40487] Re: Super-Increasing List
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Mon, 7 Apr 2003 04:56:53 -0400 (EDT)
- Organization: Universitaet Leipzig
- References: <b6m04c$efg$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
GreaterSumQ[{a_, b_}] := a < b
GreaterSumQ[{a__, b_}] := Plus[a] < b && GreaterSumQ[{a}]
SuperIncreasingQ[lst_] :=
And @@ Less @@@ Partition[lst, 2, 1] && GreaterSumQ[lst]
Regards
Jens
flip wrote:
>
> Hello,
>
> does a command or module exist which can test a list of values and determine
> if it is a super-increasing list?
>
> A super-increasing list satifies the conditions:
>
> a. the list is in increasing order
> b. each element of the list is greater than the sum of it's previous
> elements
>
> Example:
>
> list = {2, 3, 7, 15, 31}
>
> So check:
>
> a. It is in increasing order and
> b. 3 > 2, 7 > 3+ 2, 15 > 7 + 3 + 2 and 31 > 15 + 7 + 3 + 2,
>
> hence the list is super-increasing.
>
> Thanks for any inputs, Flip
>
> To email me, remove "_alpha".