Thanks for Xypron for the explanation. I have understood that there in one bag there are marbles of one color only.
Thanks once again. Regards Andrzej Mazurkiewicz Saturday 21 of March 2009 13:48:40 xypron napisał(a): > Hello Andrzej, > > Bugzilla from [email protected] wrote: > > Hello everybody. > > > > Isn't it a problem of choice of bags from a list and simply checking > > whether > > we have already chosen a bag with this color. For that you need a list > > object > > with its operations and a set object with its operations. > > I am afraid that I see no purpose in using just LP for that task. > > Each bag contains multiple colors. The task is to cover the maximum number > of colors with a given number of bags. A greedy heuristic like choosing as > next > bag the one with the most new colors does not guarantee an optimum > solution. > > Example: > Cover the maximum number of letters with 3 bags. > > all sets: > abcde > fghi > fgj > hik > j > > greedy heuristic: > abcde > fghi > hik > > optimum: > abcde > fgj > hik > > You can find a discussion of set covering problems here: > http://iris.gmu.edu/~khoffman/papers/set_covering.html > > Best regards > > Xypron _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
