int
Solver::getVariableMin(int varID ) const
{
IntegerVariable *var = varFromID(varID);
if (var)
return var->getMin();
return -1;
}
// rebuild a Gecode space with the current variable and constraints
void
Solver::updateState()
{
if (_space)
{
delete _space;
_space = NULL;
}
_space = new CustomSpace();
// create gecode variables
for (map<int, IntegerVariable*>::iterator q = _integerVariablesMap->begin(); q != _integerVariablesMap->end(); q++)
{
IntegerVariable *v = q->second;
if ((_suggest) && (_maxModification != NO_MAX_MODIFICATION)) {
v->adjustMinMax(_suggest, _maxModification);
} else {
v->adjustMinMax(_suggest);
}
v->setIndex(_space->addVariable(v->getVal(), v->getVal()));
v->setPosDeltaIndex(_space->addVariable(0, v->getMax() - v->getVal() + 1));
v->setNegDeltaIndex(_space->addVariable(0, v->getVal() - v->getMin() + 1));
v->setTotalIndex(_space->addVariable(v->getMin(), v->getMax()));
}
// add constraints to space
for (map<int, LinearConstraint*>::iterator p = _constraintsMap->begin(); p != _constraintsMap->end(); p++)
{
(p->second)->addToSpace();
}
LinExpr expr;
bool init=false;
// construct the linear combination of delta variables balanced by the weight associated with their type
for (map<int, IntegerVariable*>::iterator q = _integerVariablesMap->begin(); q != _integerVariablesMap->end(); q++)
{
IntegerVariable *currVar = q->second;
// add a delta variable for each beginning or length
int multiplier = 1;
bool isStrong = false;
// give more weight to the edited variables
if (_suggest)
{
for (unsigned int i=0; i<_strongVars->size(); i++)
if (_strongVars->at(i) == q->first)
{
isStrong = true;
//multiplier = 10;
break;
}
}
IntVarArgs vars(4);
IntArgs coeffs(4);
if (isStrong) {
vars[0] = _space->getIntVar(currVar->getTotalIndex());
vars[1] = _space->getIntVar(currVar->getIndex());
vars[2] = _space->getIntVar(currVar->getTotalIndex());
vars[3] = _space->getIntVar(currVar->getIndex());
coeffs[0] = -1;
coeffs[1] = 1;
coeffs[2] = -1;
coeffs[3] = 1;
} else {
// constraint : <initial or wanted value> + <positive delta> - <negative delta> = <optimal value>
vars[0] = _space->getIntVar(currVar->getNegDeltaIndex());
vars[1] = _space->getIntVar(currVar->getPosDeltaIndex());
vars[2] = _space->getIntVar(currVar->getTotalIndex());
vars[3] = _space->getIntVar(currVar->getIndex());
coeffs[0] = -1;
coeffs[1] = 1;
coeffs[2] = 1;
coeffs[3] = -1;
}
linear(*_space, coeffs, vars, IRT_EQ, 0);
// construction of the objective function
if (!init)
{
expr = LinExpr(vars[0], currVar->getWeight()*multiplier);
init = true;
LinExpr tmp(vars[1], currVar->getWeight()*multiplier);
expr = LinExpr(expr, Gecode::LinExpr::NT_ADD, tmp);
}
else
{
LinExpr tmp(vars[0], currVar->getWeight()*multiplier);
expr = LinExpr(expr, Gecode::LinExpr::NT_ADD, tmp);
tmp = LinExpr(vars[1], currVar->getWeight()*multiplier);
expr = LinExpr(expr, Gecode::LinExpr::NT_ADD, tmp);
}
}
// the objective function is a linear combination of the delta variables (lengths are more important than beginnings)
_space->setObjFunc(Gecode::expr(*_space, expr));
}