Maximize with multiple variable

[Dilly Day]

Hi.

I am new to constraint programming and choco solver. I tryed to use this  website exemple to maximise 3X + 4Y

 

        Model model = new Model();
IntVar OBJ = model.intVar("objective", 0, 999);
IntVar X= model.intVar("x",0,1000);
IntVar Y= model.intVar("y",0,1000);

model.scalar(new IntVar[]{X,Y}, new int[]{3,4}).post();
// Specify objective
model.setObjective(Model.MAXIMIZE, OBJ);
// Compute optimum
model.getSolver().solve();

But i have this error "Cannot resolve method 'scalar(org.chocosolver.solver.variables.IntVar[], int[])' " and I don't know why.

Any help is appreciated

[wkau...@gmail.com]

Hello Dilly Day

Your problem is in this instruction: model.scalar(new IntVar[]{X,Y}, new int[]{3,4}).post();

So you have forgotten to add the OBJ variable like that: 

model.scalar(new IntVar[] {X, Y}, new int[] {3, 4},"=",OBJ).post(); 

I correct it and after the execution I have obtened X=333 and Y=0.

I hope I answered your question?