001package net.sf.cpsolver.studentsct.heuristics.selection; 002 003import org.apache.log4j.Logger; 004 005import net.sf.cpsolver.ifs.model.Neighbour; 006import net.sf.cpsolver.ifs.solution.Solution; 007import net.sf.cpsolver.ifs.solver.Solver; 008import net.sf.cpsolver.ifs.util.DataProperties; 009import net.sf.cpsolver.ifs.util.Progress; 010import net.sf.cpsolver.studentsct.heuristics.studentord.StudentOrder; 011import net.sf.cpsolver.studentsct.heuristics.studentord.StudentRandomOrder; 012import net.sf.cpsolver.studentsct.model.Enrollment; 013import net.sf.cpsolver.studentsct.model.Request; 014import net.sf.cpsolver.studentsct.model.Student; 015 016/** 017 * Resection incomplete studends. An extension of {@link BranchBoundSelection}, 018 * where only students that are not complete ({@link Student#isComplete()} is 019 * false) and that are sectioned somewhere ({@link Student#nrAssignedRequests()} 020 * is greater then zero) are resectioned. 021 * 022 * <br> 023 * <br> 024 * 025 * @version StudentSct 1.2 (Student Sectioning)<br> 026 * Copyright (C) 2007 - 2010 Tomáš Müller<br> 027 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br> 028 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br> 029 * <br> 030 * This library is free software; you can redistribute it and/or modify 031 * it under the terms of the GNU Lesser General Public License as 032 * published by the Free Software Foundation; either version 3 of the 033 * License, or (at your option) any later version. <br> 034 * <br> 035 * This library is distributed in the hope that it will be useful, but 036 * WITHOUT ANY WARRANTY; without even the implied warranty of 037 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 038 * Lesser General Public License for more details. <br> 039 * <br> 040 * You should have received a copy of the GNU Lesser General Public 041 * License along with this library; if not see 042 * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>. 043 */ 044 045public class ResectionIncompleteStudentsSelection extends BranchBoundSelection { 046 private static Logger sLog = Logger.getLogger(ResectionIncompleteStudentsSelection.class); 047 048 public ResectionIncompleteStudentsSelection(DataProperties properties) { 049 super(properties); 050 iOrder = new StudentRandomOrder(properties); 051 if (properties.getProperty("Neighbour.ResectionIncompleteStudentsOrder") != null) { 052 try { 053 iOrder = (StudentOrder) Class.forName( 054 properties.getProperty("Neighbour.ResectionIncompleteStudentsOrder")).getConstructor( 055 new Class[] { DataProperties.class }).newInstance(new Object[] { properties }); 056 } catch (Exception e) { 057 sLog.error("Unable to set student order, reason:" + e.getMessage(), e); 058 } 059 } 060 } 061 062 @Override 063 public void init(Solver<Request, Enrollment> solver) { 064 init(solver, "Resection incomplete students..."); 065 } 066 067 /** 068 * Select neighbour. All students with an incomplete and non-empty schedule 069 * are taken, one by one in a random order. For each student a branch & 070 * bound search is employed. 071 */ 072 @Override 073 public Neighbour<Request, Enrollment> selectNeighbour(Solution<Request, Enrollment> solution) { 074 while (iStudentsEnumeration.hasNext()) { 075 Student student = iStudentsEnumeration.next(); 076 Progress.getInstance(solution.getModel()).incProgress(); 077 if (student.nrAssignedRequests() == 0 || student.isComplete()) 078 continue; 079 Neighbour<Request, Enrollment> neighbour = getSelection(student).select(); 080 if (neighbour != null) 081 return neighbour; 082 } 083 return null; 084 } 085 086}