//================================================================
// J A V A C O M M U N I T Y P R O C E S S
//
// J S R 3 3 1
//
// CONSTRAINER-BASED REFERENCE IMPLEMENTATION
//
// Copyright (c) Cork Constraint Computation Centre, 2010
// University College Cork, Cork, Ireland, www.4c.ucc.ie
// Constrainer is copyrighted by Exigen Group, USA.
//
//================================================================
package javax.constraints.impl.constraint;
import javax.constraints.Var;
import javax.constraints.impl.Problem;
import com.exigen.ie.constrainer.Constrainer;
import com.exigen.ie.constrainer.Constraint;
import com.exigen.ie.constrainer.ConstraintImpl;
import com.exigen.ie.constrainer.Failure;
import com.exigen.ie.constrainer.Goal;
import com.exigen.ie.constrainer.IntArrayCards;
import com.exigen.ie.constrainer.IntExpArray;
/**
* This constraint states that the number of constrained variables in the array
* "cardinalities" is equal to the number of occurrences of
* the values in the array "values" in the array "vars". More precisely, for each i,
* cardinalities[i] is equal to the number of occurrences of values[i] in the
* array vars. After propagation of this constraint, the minimum of
* cardinalities[i] is at least equal to the number of variables contained in
* vars bound to the value at values[i]; and the maximum of cardinalities[i] is
* at most equal to the number of variables in vars that contain the value at
* values[i] in their domain. The arrays cardinalities and values must be the
* same length, otherwise an exception will be thrown.
*
* This implementation should at least overload the method "post" to avoid
* a primitive implementation from the super class
*
*/
public class GlobalCardinality extends javax.constraints.impl.Constraint {
Var[] cardVars;
Var[] vars;
int[] values;
Var[] valueVars;
public GlobalCardinality(Var[] vars, Var[] cardVars, int[] values) {
super(vars[0].getProblem());
this.cardVars = cardVars;
this.vars = vars;
this.values = values;
this.valueVars = null;
doIt();
}
public GlobalCardinality(Var[] vars, Var[] cardVars) {
super(vars[0].getProblem());
this.cardVars = cardVars;
this.vars = vars;
this.values = new int[cardVars.length];
for (int i = 0; i < cardVars.length; i++) {
values[i] = i;
}
this.valueVars = null;
doIt();
}
public GlobalCardinality(Var[] vars, Var[] cardVars, Var[] valueVars) {
super(vars[0].getProblem());
this.cardVars = cardVars;
this.vars = vars;
this.values = null;
this.valueVars = valueVars;
doIt();
}
void doIt() {
int l1 = cardVars.length ;
int l2;
if (values != null)
l2 = values.length;
else
l2 = valueVars.length;
if (l1 != l2)
throw new RuntimeException(
"Invalid array lengths in the GlobalCardinalityI");
if (values != null)
defineNativeImpl(vars, cardVars, values);
else
defineNativeImpl(vars, cardVars, valueVars);
}
public void defineNativeImpl(Var[] vars, Var[] cardVars, int[] values) {
Problem problem = (Problem) vars[0].getProblem();
Constrainer constrainer = problem.getConstrainer();
IntExpArray cVars = problem.getExpArray(vars);
IntExpArray cCardinalityVars = problem.getExpArray(cardVars);
try {
IntExpArray cards = constrainer.distribute(cVars,values);
Constraint newC = new ConstrainerIntExpArrayEq(cards,cCardinalityVars);
setImpl(constrainer.addConstraint(newC));
} catch (Exception f) {
throw new RuntimeException(
"Failure to create GlobalCardinality constraint");
}
}
public void defineNativeImpl(Var[] vars, Var[] cardVars, Var[] valueVars) {
Problem problem = (Problem) vars[0].getProblem();
Constrainer constrainer = problem.getConstrainer();
IntExpArray cVars = problem.getExpArray(vars);
IntExpArray cValueVars = problem.getExpArray(valueVars);
IntExpArray cCardVars = problem.getExpArray(valueVars);
try {
IntArrayCards givenCards = cCardVars.cards();
IntArrayCards distributedCards = constrainer.distribute(cVars,cValueVars);
Constraint newC = new ConstrainerArrayCardsEq(distributedCards,givenCards);
setImpl(constrainer.addConstraint(newC));
} catch (Exception f) {
throw new RuntimeException(
"Failure to create GlobalCardinality constraint");
}
}
class ConstrainerArrayCardsEq extends ConstraintImpl {
IntArrayCards cards1, cards2;
public ConstrainerArrayCardsEq(IntArrayCards cards1, IntArrayCards cards2) {
super(cards1.cardAt(0).constrainer());
this.cards1 = cards1;
this.cards2 = cards2;
}
public Goal execute() throws Failure {
for(int i= 0; i < cards1.cardSize(); i++) {
constrainer().postConstraint(cards1.cardAt(i).eq(cards2.cardAt(i)));
}
return null;
}
}
class ConstrainerIntExpArrayEq extends ConstraintImpl {
IntExpArray arr1, arr2;
public ConstrainerIntExpArrayEq(IntExpArray arr1, IntExpArray arr2) {
super(arr1.elementAt(0).constrainer());
this.arr1 = arr1;
this.arr2 = arr2;
}
public Goal execute() throws Failure {
for(int i= 0; i < arr1.size(); i++) {
constrainer().postConstraint(arr1.elementAt(i).eq(arr2.elementAt(i)));
}
return null;
}
}
}