Sample input data would also be useful, including some examples that are too large for you to currently solve with your existing approach.
On Mon, Oct 5, 2015 at 4:36 AM, 'Alan Forrester' via Clojure < clojure@googlegroups.com> wrote: > On 5 Oct 2015, at 11:45, andrea crotti <andrea.crott...@gmail.com> wrote: > > > Hi everyone, > > > > I was trying for fun to solve the following problem: > > > > given a list of football players with some defined skills, find out which > > team selection would be balanced. > > > > For example given just 4 players A, B, C, D there would be the following > > team selections: > > > > - (A, B) vs (C, D) > > - (A, C) vs (B, D) > > - (A, D) vs (B, C) > > > > So it's a combinatorial problem however both inside teams and inside the > > selection the order does not count, so the number of possible teams > > is a lot smaller than the actual all possible permutations. > > > > I came up with a brute force solution here: > > > > > https://github.com/AndreaCrotti/football/blob/master/src/cljc/football/engine.cljc#L75 > > > > which however explodes already for 12 players because: > > > > - it does all the possible permutations of teams (12! in that case) > > - partition accordingly (using sets to remove duplicates) and evaluate > > every single one of them > > > > Any idea how to make this faster? > > Other advices on the code are welcome as well.. > > I find your code unclear. I can’t tell what problem you’re trying to solve > by reading the code or the comments. Do you have a specification of what > problem you’re trying to solve? If not, you should write one before you do > anything else. > > Having said that, there is one way I can see that you might make the code > slightly less bad. You define a field for your players called “:position” > and then never use it. I know almost nothing about football, but I should > think you might want the team to have at least one player in each position. > So I might do something like (group-by :position players) > > https://clojuredocs.org/clojure.core/group-by. > > Then I might generate teams by picking one player in each position or > something like that. This would reduce the number of combinations by some > unknown amount. More generally, if you have too many combinations, > introduce constraints in how you generate them. > > Alan > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
