Re: rule based program for "Deleting repeated members of a list."

*To*: mathgroup at smc.vnet.net*Subject*: [mg81938] Re: rule based program for "Deleting repeated members of a list."*From*: Szabolcs Horvát <szhorvat at gmail.com>*Date*: Sun, 7 Oct 2007 05:30:44 -0400 (EDT)*References*: <fe7j44$qga$1@smc.vnet.net>

mumat wrote: > Hi, > > I have a list s={a,b,c,c,d,e,e,f,g,g,g,h,a,b}; > > I need to write a program so that it reads the list and ignors > repeated elements; so it outputs the following: > > RepeatRemover[s]={a,b,c,d,e,f,g,h,a,b}; > > I am looking for a rule-based program to do this! > > Any help would be greatly appreciated. Why do you insist on a "rule-based" solution? The obvious (and efficient) solution is First /@ Split[s] An inefficient replacement-rule-based solution is s //. {be___, x_, x_, en___} -> {be, x, en} -- Szabolcs