org.cpsolver.instructor.constraints

Class GroupConstraint

java.lang.Object

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

org.cpsolver.ifs.model.GlobalConstraint<TeachingRequest.Variable,TeachingAssignment>

org.cpsolver.instructor.constraints.GroupConstraint

All Implemented Interfaces:

Comparable<Constraint<TeachingRequest.Variable,TeachingAssignment>>

public class GroupConstraint
extends GlobalConstraint<TeachingRequest.Variable,TeachingAssignment>

Group Constraint. This constraint implements many of the course timetabling group and flexible constraints. See GroupConstraint.ConstraintType for the list, and the appropriate GroupConstraint.ConstraintType or FlexibleConstraint constraint for their description. Because the instructor - class assignments are dynamic, the constraints are implemented by a single group constraint.

Version:

IFS 1.4 (Instructor Sectioning)
Copyright (C) 2024 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

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	GroupConstraint.Block Block of sections that go one after the other without any gap.
static interface	GroupConstraint.Check Group constraint check interface
static interface	GroupConstraint.ConstraintCreator<P> Factory class for group constraints with parameters
static class	GroupConstraint.ConstraintType Distribution types and their implementation
static interface	GroupConstraint.ConstraintTypeInterface Interface for a distribution constraint type, including its implementation
static class	GroupConstraint.Distribution Wrapper class representing one distribution preference set on an instructor.
static class	GroupConstraint.PairCheck Group constraint check interface for constraints that can be computed on individual class pairs.
static class	GroupConstraint.ParametrizedConstraintType<P> Distribution constraint with parameters.
static class	GroupConstraint.SimpleCheck Simplified group constraint check interface for constraints that can be computed on individual class pairs.
static class	GroupConstraint.SimpleTimeCheck Simplified group constraint check interface for time-only constraints that can be computed on individual class pairs.

Field Summary

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

iConstraintListeners, iId

Constructor Summary

Constructors

Constructor and Description
GroupConstraint()

Method Summary

Modifier and Type	Method and Description
void	computeConflicts(Assignment<TeachingRequest.Variable,TeachingAssignment> assignment, TeachingAssignment value, Set<TeachingAssignment> conflicts) The only method which has to be implemented by any constraint.
protected static List<GroupConstraint.Block>	getBlocks(Assignment<TeachingRequest.Variable,TeachingAssignment> assignment, Instructor instructor, int dayCode, Set<TeachingAssignment> conflicts, TeachingRequest.Variable variable, TeachingAssignment value, BitSet week, int maxBreakBetweenBTB) Return blocks for an instructor, meeting the provided parameters.
static GroupConstraint.ConstraintTypeInterface	getConstraintType(String reference, String name) Create a constraint type from the provided reference.
String	getName() Constraint's name -- for printing purposes
protected static Set<org.cpsolver.instructor.constraints.GroupConstraint.TeachingAssignmentSection>	getRelevantPlacements(Assignment<TeachingRequest.Variable,TeachingAssignment> assignment, Instructor instructor, int dayCode, Set<TeachingAssignment> conflicts, TeachingRequest.Variable variable, TeachingAssignment value, BitSet week) Return teaching assignment + section combinations for the given instructor, considering the selected value and the provided conflicts.
protected static boolean	isCorectDayAndWeek(TeachingAssignment value, int dayCode, BitSet week) Check if the given assignment has a section on the given days of the week and weeks.
protected static boolean	isCorectDayOfWeek(TeachingAssignment value, int dayCode) Check if the given assignment has a section on the given days of the week.
protected static List<GroupConstraint.Block>	mergeToBlocks(Collection<org.cpsolver.instructor.constraints.GroupConstraint.TeachingAssignmentSection> sorted, int maxBreakBetweenBTB) Merge sorted teaching assignment + section combinations into block.
protected static boolean	shareWeeksAndDay(TimeLocation t, BitSet week, int dayCode) Returns true if the time overlaps with the provided week date pattern and days of the week.
String	toString()

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

addVariable, assigned, assignedVariables, countAssignedVariables, removeVariable, unassigned, variables

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

addConstraintListener, compareTo, computeConflictsNoForwardCheck, constraintListeners, countVariables, equals, getDescription, getId, getModel, hashCode, inConflict, isConsistent, isHard, removeConstraintListener, setModel

Methods inherited from class java.lang.Object

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

Constructor Detail

GroupConstraint

public GroupConstraint()

Method Detail

computeConflicts

public void computeConflicts(Assignment<TeachingRequest.Variable,TeachingAssignment> assignment,
                             TeachingAssignment value,
                             Set<TeachingAssignment> 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<TeachingRequest.Variable,TeachingAssignment>

Parameters:

assignment - current assignment

value - 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<TeachingRequest.Variable,TeachingAssignment>

Returns:

constraint name

toString

public String toString()

Overrides:

toString in class Object

getConstraintType

public static GroupConstraint.ConstraintTypeInterface getConstraintType(String reference,
                                                                        String name)

Create a constraint type from the provided reference. Returns null when there is no match.

shareWeeksAndDay

protected static boolean shareWeeksAndDay(TimeLocation t,
                                          BitSet week,
                                          int dayCode)

Returns true if the time overlaps with the provided week date pattern and days of the week.

getRelevantPlacements

protected static Set<org.cpsolver.instructor.constraints.GroupConstraint.TeachingAssignmentSection> getRelevantPlacements(Assignment<TeachingRequest.Variable,TeachingAssignment> assignment,
                                                                                                                          Instructor instructor,
                                                                                                                          int dayCode,
                                                                                                                          Set<TeachingAssignment> conflicts,
                                                                                                                          TeachingRequest.Variable variable,
                                                                                                                          TeachingAssignment value,
                                                                                                                          BitSet week)

Return teaching assignment + section combinations for the given instructor, considering the selected value and the provided conflicts. The sections are sorted by time, and must meet during the given week and days of the week.

mergeToBlocks

protected static List<GroupConstraint.Block> mergeToBlocks(Collection<org.cpsolver.instructor.constraints.GroupConstraint.TeachingAssignmentSection> sorted,
                                                           int maxBreakBetweenBTB)

Merge sorted teaching assignment + section combinations into block.

getBlocks

protected static List<GroupConstraint.Block> getBlocks(Assignment<TeachingRequest.Variable,TeachingAssignment> assignment,
                                                       Instructor instructor,
                                                       int dayCode,
                                                       Set<TeachingAssignment> conflicts,
                                                       TeachingRequest.Variable variable,
                                                       TeachingAssignment value,
                                                       BitSet week,
                                                       int maxBreakBetweenBTB)

Return blocks for an instructor, meeting the provided parameters. Combining GroupConstraint#getRelevantPlacements(Assignment, Instructor, int, Set, Variable, TeachingAssignment, BitSet) and mergeToBlocks(Collection, int).

isCorectDayOfWeek

protected static boolean isCorectDayOfWeek(TeachingAssignment value,
                                           int dayCode)

Check if the given assignment has a section on the given days of the week.

isCorectDayAndWeek

protected static boolean isCorectDayAndWeek(TeachingAssignment value,
                                            int dayCode,
                                            BitSet week)

Check if the given assignment has a section on the given days of the week and weeks.