org.cpsolver.studentsct.heuristics.selection

Class PriorityConstructionSelection

java.lang.Object

org.cpsolver.studentsct.heuristics.selection.PriorityConstructionSelection

All Implemented Interfaces:

NeighbourSelection<Request,Enrollment>

public class PriorityConstructionSelection
extends Object
implements NeighbourSelection<Request,Enrollment>

This selection is very much like BranchBoundSelection, but it works in cycles (over all the students) assigning only the first N priority courses. It starts with N = 1 and increases it by one after each cycle. The selection ends when no student can get more requests assigned in a whole cycle. Run the selection only once (at the beginning), the selection falls back to BranchBoundSelection if there are already some requests assigned at the time of initialization.

Version:

StudentSct 1.3 (Student Sectioning)
Copyright (C) 2007 - 2014 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
class	PriorityConstructionSelection.ConstructionNeighbour Takes BranchBoundSelection.BranchBoundNeighbour but only assign the given number of assignments, corresponding to the number of cycles.

Field Summary

Fields

Modifier and Type	Field and Description
protected StudentOrder	iOrder
protected List<Student>	iStudents
protected Iterator<Student>	iStudentsEnumeration

Constructor Summary

Constructors

Constructor and Description
PriorityConstructionSelection(DataProperties properties) Constructor

Method Summary

Modifier and Type	Method and Description
Neighbour<Request,Enrollment>	branchAndBound(Solution<Request,Enrollment> solution) Find best solution for the next student using BranchBoundSelection.
void	init(Solver<Request,Enrollment> solver) Initialize
protected void	nextCycle(Solution<Request,Enrollment> solution) Increment cycle
Neighbour<Request,Enrollment>	selectNeighbour(Solution<Request,Enrollment> solution) Select neighbor.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

iStudentsEnumeration

protected Iterator<Student> iStudentsEnumeration

iOrder

protected StudentOrder iOrder

iStudents

protected List<Student> iStudents

Constructor Detail

PriorityConstructionSelection

public PriorityConstructionSelection(DataProperties properties)

Constructor

Parameters:

properties - configuration

Method Detail

init

public void init(Solver<Request,Enrollment> solver)

Initialize

Specified by:

init in interface NeighbourSelection<Request,Enrollment>

Parameters:

solver - current solver

branchAndBound

public Neighbour<Request,Enrollment> branchAndBound(Solution<Request,Enrollment> solution)

Find best solution for the next student using BranchBoundSelection.

Parameters:

solution - current selection

Returns:

generated neighbour

nextCycle

protected void nextCycle(Solution<Request,Enrollment> solution)

Increment cycle

Parameters:

solution - current solution

selectNeighbour

public Neighbour<Request,Enrollment> selectNeighbour(Solution<Request,Enrollment> solution)

Select neighbor. All students are taken, one by one in a random order. For each student a branch & bound search is employed.

Specified by:

selectNeighbour in interface NeighbourSelection<Request,Enrollment>

Parameters:

solution - given solution

Returns:

a neighbour assignment