net.sf.cpsolver.coursett.constraint
Class SpreadConstraint

java.lang.Object
  extended by net.sf.cpsolver.ifs.model.Constraint<Lecture,Placement>
      extended by net.sf.cpsolver.coursett.constraint.SpreadConstraint
All Implemented Interfaces:
Comparable<Constraint<Lecture,Placement>>, WeakeningConstraint<Lecture,Placement>
Direct Known Subclasses:
DepartmentSpreadConstraint

public class SpreadConstraint
extends Constraint<Lecture,Placement>
implements WeakeningConstraint<Lecture,Placement>

Spread given set of classes in time as much as possible. See DepartmentSpreadConstraint for more details.

Version:
CourseTT 1.2 (University Course Timetabling)
Copyright (C) 2006 - 2010 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/.

Field Summary
static boolean USE_MOST_IMPROVEMENT_ADEPTS
           
 
Fields inherited from class net.sf.cpsolver.ifs.model.Constraint
iAssignedVariables, iConstraintListeners, iId
 
Constructor Summary
SpreadConstraint(DataProperties config, String name)
           
SpreadConstraint(String name, double spreadFactor, int unassignmentsToWeaken, boolean interactiveMode)
           
 
Method Summary
 void addVariable(Lecture lecture)
          Add a variable to this constraint
 void assigned(long iteration, Placement placement)
          Given value is to be assigned to its varable.
 void computeConflicts(Placement placement, Set<Placement> conflicts)
          The only method which has to be implemented by any constraint.
 Placement getAdept(Placement placement, int[][] nrCourses, Set<Placement> conflicts)
           
 List<Placement>[][] getCourses()
           
protected  Criterion<Lecture,Placement> getCriterion()
           
 int[][] getMaxCourses()
           
 int getMaxPenalty(Placement placement)
           
 String getName()
          Constraint's name -- for printing purposes
 int[][] getNrCourses()
           
 int getPenalty()
          Department balancing penalty for this department
 int getPenalty(Placement placement)
          Department balancing penalty of the given placement
 int getPenaltyEstimate()
           
 boolean inConflict(Placement placement)
          Returns true if the given assignment is inconsistent with the existing assignments respecting this constraint.
 void init()
          Initialize constraint (to be called after all variables are added to this constraint)
 boolean isConsistent(Placement p1, Placement p2)
          Returns true if the given assignments are consistent respecting this constraint.
 String toString()
           
 void unassigned(long iteration, Placement placement)
          Given value is unassigned from its variable.
 void weaken()
          Weaken the constraint.
 void weaken(Placement value)
          Weaken the constraint enough so that it can assign the given value.
 
Methods inherited from class net.sf.cpsolver.ifs.model.Constraint
addConstraintListener, assignedVariables, compareTo, constraintListeners, countAssignedVariables, countVariables, equals, getDescription, getId, getModel, hashCode, isHard, removeConstraintListener, removeVariable, setModel, variables
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

USE_MOST_IMPROVEMENT_ADEPTS

public static boolean USE_MOST_IMPROVEMENT_ADEPTS
Constructor Detail

SpreadConstraint

public SpreadConstraint(String name,
                        double spreadFactor,
                        int unassignmentsToWeaken,
                        boolean interactiveMode)

SpreadConstraint

public SpreadConstraint(DataProperties config,
                        String name)
Method Detail

getCriterion

protected Criterion<Lecture,Placement> getCriterion()

init

public void init()
Initialize constraint (to be called after all variables are added to this constraint)


getAdept

public Placement getAdept(Placement placement,
                          int[][] nrCourses,
                          Set<Placement> conflicts)

computeConflicts

public void computeConflicts(Placement placement,
                             Set<Placement> conflicts)
Description copied from class: Constraint
The only method which has to be implemented by any constraint. It returns the values which needs to be unassigned in order to make this constraint consistent with the given value if it is assigned to its variable. The computed list of conflicting values is added to the given set of conflicts.

Specified by:
computeConflicts in class Constraint<Lecture,Placement>
Parameters:
placement - value to be assigned to its varaible
conflicts - resultant set of conflicting values

inConflict

public boolean inConflict(Placement placement)
Description copied from class: Constraint
Returns true if the given assignment is inconsistent with the existing assignments respecting this constraint. This method is used by MAC (see MacPropagation).

Overrides:
inConflict in class Constraint<Lecture,Placement>

isConsistent

public boolean isConsistent(Placement p1,
                            Placement p2)
Description copied from class: Constraint
Returns true if the given assignments are consistent respecting this constraint. This method is used by MAC (see MacPropagation).

Overrides:
isConsistent in class Constraint<Lecture,Placement>

weaken

public void weaken()
Description copied from interface: WeakeningConstraint
Weaken the constraint. This method is called if the constraint participates in an unassigned of a variable.

Specified by:
weaken in interface WeakeningConstraint<Lecture,Placement>

assigned

public void assigned(long iteration,
                     Placement placement)
Description copied from class: Constraint
Given value is to be assigned to its varable. In this method, the constraint should unassigns all varaibles which are in conflict with the given assignment because of this constraint.

Overrides:
assigned in class Constraint<Lecture,Placement>

unassigned

public void unassigned(long iteration,
                       Placement placement)
Description copied from class: Constraint
Given value is unassigned from its variable.

Overrides:
unassigned in class Constraint<Lecture,Placement>

getName

public String getName()
Description copied from class: Constraint
Constraint's name -- for printing purposes

Overrides:
getName in class Constraint<Lecture,Placement>

toString

public String toString()
Overrides:
toString in class Object

getPenalty

public int getPenalty()
Department balancing penalty for this department


getPenaltyEstimate

public int getPenaltyEstimate()

getMaxPenalty

public int getMaxPenalty(Placement placement)

getPenalty

public int getPenalty(Placement placement)
Department balancing penalty of the given placement


getMaxCourses

public int[][] getMaxCourses()

getNrCourses

public int[][] getNrCourses()

getCourses

public List<Placement>[][] getCourses()

addVariable

public void addVariable(Lecture lecture)
Description copied from class: Constraint
Add a variable to this constraint

Overrides:
addVariable in class Constraint<Lecture,Placement>

weaken

public void weaken(Placement value)
Description copied from interface: WeakeningConstraint
Weaken the constraint enough so that it can assign the given value.

Specified by:
weaken in interface WeakeningConstraint<Lecture,Placement>