Hello ,

I have a small question. How can I translate this constraint to C++ code, I could not be sure about forall parts ?

the constraint :

sum(m in nbMachines) X[p][m][t] = quantity[p][t], forall p and for all t

What I did :

for (IloInt p = 0; p < nbProducts; ++p) {

for (IloInt t = 0; t < nbPeriods; ++t)

IloExpr v(env);

for (IloInt m = 0; m < nbMachines; ++m)

v += X[p][m][t];

model.add(v == quantity[p][t]);

v.end();

}

is it correct ? If not, how can we fix it ?

Thank you in advance ;

Hello Milena,

Your code looks pretty good only {} are missing.

I hope this helps,

Chris.

Hello Chris ,

Thank you for your reply; After I asked the question, I raelised that I forgot "}" and I modified the code. However, there is somethng I do not understand: I export the model and write the constrainton lp file like this:

 IloCplex cplex(env);

 cplex.extract(model);

 cplex.exportModel("Source.lp");

Btw;

NbProducts:3

Nbmachines:5

NbPeriods:6

What I expect :

X[1][1][1]+X[1][2][1]+X[1][3][1]+X[1][4][1]+X[1][5][1]=quantity[1][1]

However,

I get:

c1: x1 + x2 + x3 + x4 + x5 = quantity

c2: x6 + x7 + x8 + x9 + x10 = quantity

c3: x11 + x12 + x13 + x14 + x15 = quantity

…...………………………………..……...

………………...……......………..….

 c18: x86 + x87 + x88 + x89 + x90 = quantity

Why it is like that? How can I solve this problem ?

Thank you in advance