org.cpsolver.coursett.constraint

Class BreakFlexibleConstraint

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.BreakFlexibleConstraint

All Implemented Interfaces:

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

public class BreakFlexibleConstraint
extends FlexibleConstraint

The Break constraint checks for instructor lunch break or a break in general in between the given classes.
It has three parameters: a start and an end time of a window in which the break is required / preferred, and a minimal length of a break that is needed.
Reference _Break:132:162:30_ translates to a break of at least 30 minutes between 11 am (slot 132) and 1:30 pm (slot 162).

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 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
BreakFlexibleConstraint(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>	getBreakBlocks(Assignment<Lecture,Placement> assignment, int dayCode, Set<Placement> conflicts, Placement value, HashMap<Lecture,Placement> assignments, BitSet week) Creates a list of consecutive blocks with back-to-back classes.
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

Constructor Detail

BreakFlexibleConstraint

public BreakFlexibleConstraint(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

getBreakBlocks

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

Creates a list of consecutive blocks with back-to-back classes.

Parameters:

assignment - current assignment

dayCode - days of week

conflicts - conflicting assignment

value - placement in question

assignments - other considered assignments

week - selected week

Returns:

classes merged into blocks

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