net.sf.cpsolver.studentsct.model

Class Request

java.lang.Object

net.sf.cpsolver.ifs.model.Variable<Request,Enrollment>

net.sf.cpsolver.studentsct.model.Request

All Implemented Interfaces:

Comparable<Request>

Direct Known Subclasses:

CourseRequest, FreeTimeRequest

public abstract class Request
extends Variable<Request,Enrollment>

Representation of a request of a student for a course(s) or a free time. This can be either CourseRequest or FreeTimeRequest. Each request contains id, priority, weight, and a student. A request can be also marked as alternative.

For each student, all non-alternative requests should be satisfied (an enrollment is assigned to a request). If not, an alternative request can be assigned instead of a non-alternative course request. In the case when only one of two requests can be assigned, the one with the lowest priority is preferred.

Version:

StudentSct 1.2 (Student Sectioning)
Copyright (C) 2007 - 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

Fields

Modifier and Type	Field and Description
static boolean	sCacheValues True means that method values() will cache its results.

Fields inherited from class net.sf.cpsolver.ifs.model.Variable

iValue

Constructor Summary

Constructors

Constructor and Description
Request(long id, int priority, boolean alternative, Student student) Constructor

Method Summary

Modifier and Type	Method and Description
void	assign(long iteration, Enrollment enrollment) Assign given enrollment to this request.
int	compareTo(Request r) Compare to requests, non-alternative requests go first, otherwise use priority (a request with lower priority goes first)
abstract List<Enrollment>	computeEnrollments() Compute available enrollments
boolean	equals(Object o)
abstract double	getBound() Get bound, i.e., the value of the best possible enrollment
long	getId() Request id
int	getPriority() Request priority -- if there is a choice, request with lower priority is more preferred to be assigned
Student	getStudent() Student to which this request belongs
double	getWeight() Request weight, set by default to 1.0, defines the amount of space which will be taken in the section by this request.
int	hashCode()
boolean	isAlternative() True, if the request is alternative (alternative request can be assigned instead of a non-alternative course requests, if it is left unassigned)
boolean	isAssigned() Return true if request is assigned.
void	setPriority(int priority) Set request priority
void	setWeight(double weight) Set request weight.
void	unassign(long iteration) Unassign currently assigned enrollment from this request.
List<Enrollment>	values() Domain of this variable -- list of available enrollments.

Methods inherited from class net.sf.cpsolver.ifs.model.Variable

addContstraint, addVariableListener, constraints, constraintVariables, countAssignments, getAssignment, getBestAssignment, getBestAssignmentIteration, getDescription, getExtra, getInitialAssignment, getModel, getName, getVariableListeners, hardConstraints, hasAssignment, hasInitialAssignment, hasValues, lastAssignmentIteration, lastUnassignmentIteration, removeContstraint, removeInitialValue, removeValue, removeVariableListener, setBestAssignment, setExtra, setInitialAssignment, setModel, setValues, softConstraints, toString

Methods inherited from class java.lang.Object

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

Field Detail

sCacheValues

public static boolean sCacheValues

True means that method values() will cache its results.

Constructor Detail

Request

public Request(long id,
               int priority,
               boolean alternative,
               Student student)

Constructor

Parameters:

id - course/free time request unique id

priority - request priority -- if there is a choice, request with lower priority is more preferred to be assigned

alternative - true if the request is alternative (alternative request can be assigned instead of a non-alternative course requests, if it is left unassigned)

student - student to which this request belongs

Method Detail

getId

public long getId()

Request id

Overrides:

getId in class Variable<Request,Enrollment>

getPriority

public int getPriority()

Request priority -- if there is a choice, request with lower priority is more preferred to be assigned

setPriority

public void setPriority(int priority)

Set request priority

isAlternative

public boolean isAlternative()

True, if the request is alternative (alternative request can be assigned instead of a non-alternative course requests, if it is left unassigned)

getStudent

public Student getStudent()

Student to which this request belongs

compareTo

public int compareTo(Request r)

Compare to requests, non-alternative requests go first, otherwise use priority (a request with lower priority goes first)

Specified by:

compareTo in interface Comparable<Request>

Overrides:

compareTo in class Variable<Request,Enrollment>

computeEnrollments

public abstract List<Enrollment> computeEnrollments()

Compute available enrollments

values

public List<Enrollment> values()

Domain of this variable -- list of available enrollments. Method computeEnrollments() is used.

Overrides:

values in class Variable<Request,Enrollment>

assign

public void assign(long iteration,
                   Enrollment enrollment)

Assign given enrollment to this request. This method also calls Assignment.assigned(Enrollment) on for all the assignments of the enrollment.

Overrides:

assign in class Variable<Request,Enrollment>

Parameters:

iteration - current iteration

enrollment - the value to be assigned

unassign

public void unassign(long iteration)

Unassign currently assigned enrollment from this request. This method also calls Assignment.unassigned(Enrollment) on for all the assignments of the current enrollment.

Overrides:

unassign in class Variable<Request,Enrollment>

Parameters:

iteration - current iteration

getBound

public abstract double getBound()

Get bound, i.e., the value of the best possible enrollment

getWeight

public double getWeight()

Request weight, set by default to 1.0, defines the amount of space which will be taken in the section by this request.

setWeight

public void setWeight(double weight)

Set request weight. It defines the amount of space which will be taken in the section by this request.

isAssigned

public boolean isAssigned()

Return true if request is assigned.

hashCode

public int hashCode()

Overrides:

hashCode in class Variable<Request,Enrollment>

equals

public boolean equals(Object o)

Overrides:

equals in class Variable<Request,Enrollment>