org.cpsolver.coursett.constraint

Class MaxBlockFlexibleConstraint

java.lang.Object

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

org.cpsolver.ifs.assignment.context.ConstraintWithContext<Lecture,Placement,FlexibleConstraint.FlexibleConstraintContext>

org.cpsolver.coursett.constraint.FlexibleConstraint

org.cpsolver.coursett.constraint.MaxBlockFlexibleConstraint

All Implemented Interfaces:

Comparable<Constraint<Lecture,Placement>>, CanHoldContext, HasAssignmentContext<Lecture,Placement,FlexibleConstraint.FlexibleConstraintContext>

public class MaxBlockFlexibleConstraint
extends FlexibleConstraint

The MaxBlock constraint checks for too big blocks of back-to-back classes of an instructor.
It has two parameters: a maximal length of a back-to-back block that is allowed and a minimal length of a break between two classes not to be considered in the same block.
Reference _MaxBlock:120:30_ translates to a maximal block of at most 2 hours (120 minutes) with classes not more than 30 minutes a part.

Version:

CourseTT 1.3 (University Course Timetabling)
Copyright (C) 2013 Matej Lukac

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:

Matej Lukac

Nested Class Summary

Nested classes/interfaces inherited from class org.cpsolver.coursett.constraint.FlexibleConstraint

FlexibleConstraint.Block, FlexibleConstraint.FlexibleConstraintContext, FlexibleConstraint.FlexibleConstraintType, FlexibleConstraint.PlacementTimeComparator

Field Summary

Fields

Modifier and Type	Field and Description
protected int	iMaxBlockSlotsBTB

Fields inherited from class org.cpsolver.coursett.constraint.FlexibleConstraint

iConstraintType, iDayOfWeekOffset, iPreciseDateComputation, iPreference, iReference, iWeeks

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

iConstraintListeners, iId

Fields inherited from interface org.cpsolver.ifs.assignment.context.CanHoldContext

sMaxSize

Constructor Summary

Constructors

Constructor and Description
MaxBlockFlexibleConstraint(Long id, String owner, String preference, String reference)

Method Summary

Modifier and Type	Method and Description
void	computeConflicts(Assignment<Lecture,Placement> assignment, Placement value, Set<Placement> conflicts) The only method which has to be implemented by any constraint.
List<FlexibleConstraint.Block>	getBlocks(Assignment<Lecture,Placement> assignment, int dayCode, Set<Placement> conflicts, Placement value, HashMap<Lecture,Placement> assignments, BitSet week)
double	getNrViolations(Assignment<Lecture,Placement> assignment, Set<Placement> conflicts, HashMap<Lecture,Placement> assignments) Return current number of violations.

Methods inherited from class org.cpsolver.coursett.constraint.FlexibleConstraint

createAssignmentContext, getCurrentPreference, getDayOfWeekOffset, getName, getOwner, getPrologPreference, getReference, getRelevantPlacements, getType, getWeeks, isConsistent, isHard, isPreciseDateComputation, mergeToBlocks, shareWeeksAndDay, toString

Methods inherited from class org.cpsolver.ifs.assignment.context.ConstraintWithContext

assigned, getAssignmentContextReference, getContext, getContext, setAssignmentContextReference, setModel, unassigned

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

addConstraintListener, addVariable, assignedVariables, compareTo, computeConflictsNoForwardCheck, constraintListeners, countAssignedVariables, countVariables, equals, getDescription, getId, getModel, hashCode, inConflict, removeConstraintListener, removeVariable, variables

Methods inherited from class java.lang.Object

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

Field Detail

iMaxBlockSlotsBTB

protected int iMaxBlockSlotsBTB

Constructor Detail

MaxBlockFlexibleConstraint

public MaxBlockFlexibleConstraint(Long id,
                                  String owner,
                                  String preference,
                                  String reference)

Parameters:

id - constraint unique id

owner - identifier of distribution preference the constraint was created for

preference - time preference ("R" for required, "P" for prohibited, "-2", "-1", "1", "2" for soft preference)

reference - parameters of the constraint in String form

Method Detail

computeConflicts

public void computeConflicts(Assignment<Lecture,Placement> assignment,
                             Placement value,
                             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:

assignment - current assignment

value - value to be assigned to its variable

conflicts - resultant set of conflicting values

getBlocks

public List<FlexibleConstraint.Block> getBlocks(Assignment<Lecture,Placement> assignment,
                                                int dayCode,
                                                Set<Placement> conflicts,
                                                Placement value,
                                                HashMap<Lecture,Placement> assignments,
                                                BitSet week)

getNrViolations

public double getNrViolations(Assignment<Lecture,Placement> assignment,
                              Set<Placement> conflicts,
                              HashMap<Lecture,Placement> assignments)

Description copied from class: FlexibleConstraint

Return current number of violations.

Specified by:

getNrViolations in class FlexibleConstraint

Parameters:

assignment - current assignment

conflicts - conflicting placements to be unassigned

assignments - assigned placements

Returns:

the number of violations of the constraint during days and all weeks of the semester