<div class="gmail_quote">Hello everybody !<br><br>I first asked my question on list Osi, thinking it may be an interface-related problem, but we found no answer and I hope you may be knowledgeable on this point :-)<br><br>
Here is my problem : I have been solving continuous and integer programs with Cbc for some time now and it works absolutely fine ! <br>Now, I would like to add some spices to what I am doing with it, by trying to compute several integers solutions to linear programs.<br>
<br>For example, I would like the following program ( with x and y binary variables ) :<br><br>Max:<br> x + y<br>Constraints :<br> x + y <= 1<br><br>to return the two solutions : x = 0, y=1 and x=1,y=0.<br><br>I saw there were functions in OsiClpInterface like setMaximumSolution and getMaximumSolutions. I also found the function getSolutionCount in CbcModel but it does not seem to do what I want it to do ;-)<br>
I set the Maximum Number of Solutions to 200 and checked with getMaximumSolutions there was no problem assigning the value, but when I solve the previous problem getSolutionCount always return 1. Would you know how to make it work properly ? Would you have an example where several solutions are found, which I could read to see both how it is done, and how to iterate through all the solutions found after ? It it possible to set the infinity as the MaximumNumber of solution if I want all of them ( I know this can grow quite huge ! )<br>
<br>From what I learnt on list Osi, it may well be that these functions act very differently from what I first thought, and that the feature I am looking for is not implemented yet. I am actually trying to enumerate *** all the optimal solutions *** of a MIP containing binary/integer variables, and this would just imply that the solver should nut cut branch whose objective is "lesser or equal" to the current best integer solution, but only cut branches whose objective is "strictly less" than the current best integer solution.<br>
<br>I assure you I know several people who may be tremendously interested by such a feature in CBC !! :-)<br><br>Thank you very much for your help !<br><font color="#888888"><br>Nathann Cohen<br>
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