Re: Finding Position in an ordered list

*To*: mathgroup at smc.vnet.net*Subject*: [mg57770] Re: [mg57720] Finding Position in an ordered list*From*: János TÓTH <janostothmeister at gmail.com>*Date*: Wed, 8 Jun 2005 03:21:19 -0400 (EDT)*References*: <200506060821.EAA12541@smc.vnet.net> <76e8f81805060620315232bc54@mail.gmail.com>*Reply-to*: János TÓTH <janostothmeister at gmail.com>*Sender*: owner-wri-mathgroup at wolfram.com

Dear All, 0. Now I disclose that I am looking for a word in a dictionary. 1. Thank for the BinarySearch idea. It is much faster than Position. 2. The idea of interpolation in the case of numbers is fantastic. 3. However, I tried BinarySearch[{a,b,c},b] without being evaluated. Thus, I need further help. Thank for all of you. Janos On 6/7/05, yehuda ben-shimol <bsyehuda at gmail.com> wrote: > The immediate answer is to perform a binary search. This will result > with a complexity of O(Log[2,n]) (n being the length of the list) and > not O(n). > There is an implementation of a binary search algorithm in the > Combinatorica package > << DiscreteMath`Combinatorica` > ? BinarySearch > > good luck > yehuda > On 6/6/05, janostothmeister at gmail.com <janostothmeister at gmail.com> wrote: > > I wonder if it is possible to use the knowledge > > that a list in which I am looking for the position > > of an element is ordered. I want a quicker solution then e.g. > > lis={ac,dmk,rfg,sty,zxxer} > > Position[lis,sty] > > > > I am certainly interested in longer lists... > > > > Thank you, > > > > Janos > > > > > > >

**Follow-Ups**:**Re: Re: Finding Position in an ordered list***From:*Andrzej Kozlowski <andrzej@akikoz.net>

**References**:**Finding Position in an ordered list***From:*janostothmeister@gmail.com