org.cpsolver.ifs.example.csp

Class CSPBinaryConstraint

java.lang.Object

org.cpsolver.ifs.model.Constraint<V,T>

org.cpsolver.ifs.model.BinaryConstraint<CSPVariable,CSPValue>

org.cpsolver.ifs.example.csp.CSPBinaryConstraint

All Implemented Interfaces:

Comparable<Constraint<CSPVariable,CSPValue>>

public class CSPBinaryConstraint
extends BinaryConstraint<CSPVariable,CSPValue>

CSP binary constraint.

This class only implements the generation of a binary CSP constraint and the consistency check.

Version:

IFS 1.3 (Iterative Forward Search)
Copyright (C) 2006 - 2014 Tomáš Müller
muller@unitime.org
http://muller.unitime.org

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not see http://www.gnu.org/licenses/.

Author:

Tomáš Müller

Field Summary

Fields inherited from class org.cpsolver.ifs.model.Constraint

iConstraintListeners, iId

Constructor Summary

Constructors

Constructor and Description
CSPBinaryConstraint(int id, int nrCompatiblePairs) Constructor

Method Summary

Modifier and Type	Method and Description
void	computeConflicts(Assignment<CSPVariable,CSPValue> assignment, CSPValue aValue, Set<CSPValue> conflicts) Add the other variable to the set of conflicts, if it is not compatible with the given value.
String	getName() Constraint's name -- for printing purposes
void	init(Random rndNumGen) Initializes the constraint.
boolean	isConsistent(CSPValue value1, CSPValue value2) True if the pair of given values is compatible.

Methods inherited from class org.cpsolver.ifs.model.BinaryConstraint

addVariable, another, first, isFirst, second

Methods inherited from class org.cpsolver.ifs.model.Constraint

addConstraintListener, assigned, assignedVariables, compareTo, computeConflictsNoForwardCheck, constraintListeners, countAssignedVariables, countVariables, equals, getDescription, getId, getModel, hashCode, inConflict, isHard, removeConstraintListener, removeVariable, setModel, unassigned, variables

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CSPBinaryConstraint

public CSPBinaryConstraint(int id,
                           int nrCompatiblePairs)

Constructor

Parameters:

id - constraint id

nrCompatiblePairs - number of compatible pairs of values in the constraint

Method Detail

init

public void init(Random rndNumGen)

Initializes the constraint. Randomly generates the given number of compatible pairs of values.

Parameters:

rndNumGen - random number generator

isConsistent

public boolean isConsistent(CSPValue value1,
                            CSPValue value2)

True if the pair of given values is compatible.

Overrides:

isConsistent in class Constraint<CSPVariable,CSPValue>

Parameters:

value1 - a value

value2 - a value

Returns:

true if the constraint is ok with the assignment

computeConflicts

public void computeConflicts(Assignment<CSPVariable,CSPValue> assignment,
                             CSPValue aValue,
                             Set<CSPValue> conflicts)

Add the other variable to the set of conflicts, if it is not compatible with the given value.

Specified by:

computeConflicts in class Constraint<CSPVariable,CSPValue>

Parameters:

assignment - current assignment

aValue - value to be assigned to its variable

conflicts - resultant set of conflicting values

getName

public String getName()

Description copied from class: Constraint

Constraint's name -- for printing purposes

Overrides:

getName in class Constraint<CSPVariable,CSPValue>

Returns:

constraint name