Re: generating subsets

*To*: mathgroup at smc.vnet.net*Subject*: [mg21612] Re: [mg21588] generating subsets*From*: "Tomas Garza" <tgarza at mail.internet.com.mx>*Date*: Sun, 16 Jan 2000 22:43:57 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Michael Gass [mgass at bach.math.csbsju.edu] wrote: > I need an _efficient_ procedure for generating all the subsets > of a given set. The procedure should produce output as follows: > > subSets[{a,b,c}] > produces > {{}, {a}, {b}, {c}, {a,b}, {a,c}, {b,c}, {a,b,c}} > > I have written a recursive procedure to do this, but > it takes quite a while to generate, say, the 512 subsets > of a 9 element set and I need to work with somewhat larger > sets. This will do what you want: In[1]:= << DiscreteMath`Combinatorica` In[2]:= Table[KSubsets[{a, b, c, d, e, f, g, h, i}, j], {j, 0, 9}] Tomas Garza Mexico City