net.sf.cpsolver.studentsct.model
Class Request

java.lang.Object
  net.sf.cpsolver.ifs.model.Variable
      net.sf.cpsolver.studentsct.model.Request

All Implemented Interfaces:

Comparable

Direct Known Subclasses:

CourseRequest, FreeTimeRequest

public abstract class Request
extends Variable
implements Comparable

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 1.1 (Student Sectioning)
Copyright (C) 2007 Tomáš Müller
muller@unitime.org
Lazenska 391, 76314 Zlin, Czech Republic

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 2.1 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, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

Field Summary

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

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

Method Summary

void	assign(long iteration, Value value) Assign given enrollment to this request.
int	compareTo(Object o) Compare to requests, non-alternative requests go first, otherwise use priority (a request with lower priority goes first)
abstract Vector	computeEnrollments() Compute available enrollments
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.
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)
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.
Vector	values() Domain of this variable -- list of available enrollments.

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

addContstraint, addVariableListener, constraints, constraintVariables, countAssignments, equals, getAssignment, getBestAssignment, getBestAssignmentIteration, getDescription, getExtra, getInitialAssignment, getModel, getName, getVariableListeners, hardConstraints, hasAssignment, hashCode, 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

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(Object o)

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

Specified by:

compareTo in interface Comparable

Overrides:

compareTo in class Variable

computeEnrollments

public abstract Vector computeEnrollments()

Compute available enrollments

values

public Vector values()

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

Overrides:

values in class Variable

assign

public void assign(long iteration,
                   Value value)

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

Parameters:

iteration - current iteration

value - 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

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.