Originally posted by: has246

I have a model which i want to apply. The objective function is as follows:

Ithe x is a binary variable which is held in a IloIntVar[][][]

the second part on the right was easy. My problem is with the left part.

I tried ti do it as follows

for (int i = 1; i <= 5; i++)
{
    IloLinearIntExpr exp = cplex.linearIntExpr();
    for (int j = 1; j <= 4; j++)
    {
        for ( int k = 1; k <= 3; k++)
        {
            // this is my problem
            exp.addTerm(1, x[i][r][p]);
        }
    }
}

how do I add the: 1 - the term here?

and how do I multiply it by 5. I tried it alot and I cant cast Ilointexpr to IloLinearIntExpr

Thanks for any help

There are two options:

1. Use the more generic type IloIntExpr, like so

         for (int i = 1; i <= 5; i++) {
            IloLinearIntExpr exp = cplex.linearIntExpr();
            for (int j = 1; j <= 4; j++) {
               for ( int k = 1; k <= 3; k++) {
                  exp.addTerm(1, x[i][j][k]);
               }
            }
            IloIntExpr a = cplex.diff(1, exp);
            IloIntExpr b = cplex.prod(5, a);
         }

2. Explicitly expand the '5 *' and '1 - ' operations:

         for (int i = 1; i <= 5; i++) {
            IloLinearIntExpr exp = cplex.linearIntExpr(5);
            for (int j = 1; j <= 4; j++) {
               for ( int k = 1; k <= 3; k++) {
                  exp.addTerm(-5, x[i][j][k]);
               }
            }
         }