Re: 1-liner wanted

*To*: mathgroup at smc.vnet.net*Subject*: [mg121661] Re: 1-liner wanted*From*: Peter Pein <petsie at dordos.net>*Date*: Sat, 24 Sep 2011 22:33:51 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <j5hdfe$7j5$1@smc.vnet.net>

Am 23.09.2011 09:45, schrieb Kent Holing: > Let's assume we have a list of elements of the type {x,y,z} for x, y and z integers. And, if needed we assume x< y< z. We also assume that the list contains at least 3 such triples. > > Can Mathematica easily solve the following problem? To detect at least three elements from the list of the type {a,b,.}, {b,c,.} and {a,c,.}? I am more intereseted in an elegant 1-liner than computational efficient solutions. > > Example: > Givenlist ={1,2,3},{2,4,5],{6,7,8},{1,4,6},{7,8,9},{11,12,13}}; > should return > {{1,2,3},{2,4,5},{1,4,6}} > > Kent Holing, > Norway > This looks like some kind of homework, but my proposal is far from being elegant - so what... In[1]:= Givenlist = {{1, 2, 3}, {2, 4, 5}, {6, 7, 8}, {6, 8, new}, {1, 4, 6}, {7, 8, 9}, {11, 12, 13}}; In[2]:= With[{pat = Permutations[{{a, b, x}, {b, c, y}, {a, c, z}}]}, Flatten[(ReplaceList[Givenlist, Insert[Map[Pattern[#1, _] & , #1, {2}], ___, Transpose[{Range[4]}]] :> pat[[1]]] & ) /@ pat, 1]] Out[2]= {{{1, 2, 3}, {2, 4, 5}, {1, 4, 6}}, {{6, 7, 8}, {7, 8, 9}, {6, 8, new}}} or - to keep elements in order - a small change immediately after ":>" In[3]:= With[{pat = Permutations[{{a, b, x}, {b, c, y}, {a, c, z}}]}, Flatten[(ReplaceList[Givenlist, Insert[Map[Pattern[#1, _] & , #1, {2}], ___, Transpose[{Range[4]}]] :> #] & ) /@ pat, 1]] Out[3]= {{{1, 2, 3}, {2, 4, 5}, {1, 4, 6}}, {{6, 7, 8}, {6, 8, new}, {7,8,9}}} Peter Pein, Germany