/**
* Makes a CSP consisting of binary constraints arc-consistent.
*
* @return An object which indicates success/failure and contains data to
* undo the operation.
*/
public IInferenceLog <VAR, VAL> apply(CSP <VAR, VAL> csp)
{
ICollection <VAR> queue = CollectionFactory.CreateFifoQueueNoDuplicates <VAR>();
queue.AddAll(csp.getVariables());
DomainLog <VAR, VAL> log = new DomainLog <VAR, VAL>();
reduceDomains(queue, csp, log);
return(log.compactify());
}
/**
* Reduces the domain of the specified variable to the specified value and
* reestablishes arc-consistency. It is assumed that the provided CSP was
* arc-consistent before the call.
*
* @return An object which indicates success/failure and contains data to
* undo the operation.
*/
public IInferenceLog <VAR, VAL> apply(CSP <VAR, VAL> csp, Assignment <VAR, VAL> assignment, VAR var)
{
Domain <VAL> domain = csp.getDomain(var);
VAL value = assignment.getValue(var);
if (!domain.contains(value))
{
throw new Exception("domain does not contain value");
}
DomainLog <VAR, VAL> log = new DomainLog <VAR, VAL>();
if (domain.size() > 1)
{
ICollection <VAR> queue = CollectionFactory.CreateFifoQueue <VAR>();
queue.Add(var);
log.storeDomainFor(var, domain);
csp.setDomain(var, new Domain <VAL>(value));
reduceDomains(queue, csp, log);
}
return(log.compactify());
}