Forum Discussion
MPVAR mod integer
Hi all,
I'm wondering is it possible to modulo an mpvar. I have a set of mpvars Xs which are binary and I want to have Sum(i in set) Xi mod 2 = 0 (in other words), the sum of the binary variabl...
Enclosed you find a full example (just for the sake of completeness):
model Modulo options noimplicit, keepassert uses "mmxprs"; declarations I = 1..3 x: array (I) of mpvar y: mpvar obj: linctr end-declarations procedure createModel ! all x variables are binary forall (i in I) do x(i) is_binary end-do ! y is an auxiliary integer variable y is_integer ! (sum (i in I) x(i)) mod 2 = 0 sum(i in I) x(i) = 2 * y ! objective: maximize sum of x(i) obj := sum(i in I) x(i) end-procedure procedure showSolution writeln("(sum(i in I) x(i)) mod 2 = ", (sum(i in I) x(i).sol) mod 2) forall (i in I) do writeln("x(",i,") = ", x(i).sol) end-do end-procedure procedure main createModel maximize(obj) showSolution end-procedure main end-model