Re: [Choco-users] maximize/minimize

[Hadrien C. <had...@em...>]

Hello,

That's true, the "solver.setFirstSolution(true)" should be a
"solver.setFirstSolution(false);".
we need to quickly define the api to avoid such mistakes.

public static void main(String[] args) {
    Problem pb =3D new Problem();
    IntVar fctObj =3D pb.makeBoundIntVar("objectif",-10,1000);
    IntVar v1 =3D pb.makeEnumIntVar("v1",1,10);
    IntVar v2 =3D pb.makeEnumIntVar("v2",-3,10);
    IntVar v3 =3D pb.makeEnumIntVar("v3",1,10);

    pb.post(pb.eq(pb.sum(new IntVar[]{v1,v2,v3}),fctObj));


    Solver solver =3D pb.getSolver();
    solver.setDoMaximize(false);
    solver.setObjective(fctObj);
    solver.setRestart(false);
    solver.setFirstSolution(false);
    solver.setValIterator(new DecreasingDomain());
    solver.generateSearchSolver(pb);
    solver.launch();
  }

You will finally obtain :

... solution with cost objectif:-1
0[+15] millis.
0[+3] nodes
Pb[4 vars, 1 cons]
objectif[-1, -1]
v1{1}
v2{-3}
v3{1}

Hadrien

----- Original Message -----=20
From: "coletta" <co...@li...>
To: <cho...@li...>
Sent: Tuesday, October 26, 2004 6:03 PM
Subject: Re: [Choco-users] maximize/minimize


> Le lun, 25/10/2004 =E0 14:08 +0200, Hadrien Cambazard a =E9crit :
>
> > The api concerning minization and maximization in not yet available o=
n
the
> > Problem object. However, you can look at the following code which giv=
e
you
> > an example of minimization. You only need to use the Solver object an=
d
> > specify a couple of options :
> >
> > public static void main(String[] args) {
> >     Problem pb =3D new Problem();
> >     IntVar fctObj =3D pb.makeBoundIntVar("objectif",-10,1000);
> >     IntVar v1 =3D pb.makeEnumIntVar("v1",1,10);
> >     IntVar v2 =3D pb.makeEnumIntVar("v2",-3,10);
> >     IntVar v3 =3D pb.makeEnumIntVar("v3",1,10);
> >
> >     pb.post(pb.eq(pb.sum(new IntVar[]{v1,v2,v3}),fctObj));
> >
> >
> >     Solver solver =3D pb.getSolver();
> >     solver.setDoMaximize(false);
> >     solver.setObjective(fctObj);
> >     solver.setRestart(false);
> >     solver.setFirstSolution(true);
> >     solver.generateSearchSolver(pb);
> >     solver.launch();
> >   }
>
> Hello guys,
>
>   I'm sorry, but i don't seem to work :-(
>   By selecting another Value Ordering, for instance:
> inserting the line "solver.setValIterator(new DecreasingDomain());",
> i obtain:
>
> $ java Test
> ... solution with cost objectif:30
> Pb[4 vars, 1 cons]
> objectif[30, 30]
> v1{10}
> v2{10}
> v3{10}
>
> Do i miss something ?
>
> --
> R=E9mi
>
>
>
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