Re: Filtering a list of list for certain elements that

*To*: mathgroup at smc.vnet.net*Subject*: [mg88842] Re: [mg88834] Filtering a list of list for certain elements that*From*: Carl Woll <carlw at wolfram.com>*Date*: Mon, 19 May 2008 05:15:23 -0400 (EDT)*References*: <200805181134.HAA23914@smc.vnet.net>

Steven Siew wrote: >I have a list of lists > >mylist={{a,b,c},{a,c,b},{b,a,c},{b,c,a},{c,a,b},{c,b,a}} > >I want to filter out all lists that have "a being a neighbor to b". > >I am looking for the following result. > >{{a,c,b},{b,c,a}} > > >For this toy example, I can probably do it by hand but my real problem >has 120 lists in a list. And I need to filter out various combination >of letters like "s cannot be next to d" , "s cannot be next to j" , "c >cannot be next to j" , "h cannot be next to d" and "h cannot be next >to s". > > One possibility: In[267]:= DeleteCases[mylist, {___, PatternSequence[a, b] | PatternSequence[b, a], ___}] Out[267]= {{a, c, b}, {b, c, a}} Carl Woll Wolfram Research

**References**:**Filtering a list of list for certain elements that are neighbours***From:*Steven Siew <stevensiew2@gmail.com>