001    package net.sf.cpsolver.ifs.example.csp;
002    
003    import java.util.ArrayList;
004    import java.util.List;
005    import java.util.Random;
006    
007    import net.sf.cpsolver.ifs.model.Variable;
008    
009    /**
010     * CSP variable. <br>
011     * <br>
012     * This class only implements generation of variable's values (domain)
013     * 
014     * @version IFS 1.2 (Iterative Forward Search)<br>
015     *          Copyright (C) 2006 - 2010 Tomas Muller<br>
016     *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
017     *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
018     * <br>
019     *          This library is free software; you can redistribute it and/or modify
020     *          it under the terms of the GNU Lesser General Public License as
021     *          published by the Free Software Foundation; either version 3 of the
022     *          License, or (at your option) any later version. <br>
023     * <br>
024     *          This library is distributed in the hope that it will be useful, but
025     *          WITHOUT ANY WARRANTY; without even the implied warranty of
026     *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
027     *          Lesser General Public License for more details. <br>
028     * <br>
029     *          You should have received a copy of the GNU Lesser General Public
030     *          License along with this library; if not see
031     *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
032     */
033    public class CSPVariable extends Variable<CSPVariable, CSPValue> {
034        private int iKernelId = -1;
035    
036        /**
037         * Constructor
038         * 
039         * @param domainSize
040         *            number of values of the variable
041         */
042        public CSPVariable(int id, int domainSize) {
043            this(id, domainSize, -1);
044        }
045    
046        /**
047         * Constructor
048         * 
049         * @param domainSize
050         *            number of values of the variable
051         * @param kernelId
052         *            kernel id (for structured CSP)
053         */
054        public CSPVariable(int id, int domainSize, int kernelId) {
055            super(null);
056            iId = id;
057            iKernelId = kernelId;
058            setValues(computeValues(domainSize));
059        }
060    
061        /** Get kernel id */
062        public int getKernelId() {
063            return iKernelId;
064        }
065    
066        /**
067         * Generate an intial value (for MPP and for forcing of existance of a
068         * solution)
069         */
070        public void generateInitialValue(Random rnd) {
071            CSPValue aValue = values().get((int) (rnd.nextFloat() * values().size()));
072            setInitialAssignment(aValue);
073        }
074    
075        private List<CSPValue> computeValues(int domainSize) {
076            List<CSPValue> values = new ArrayList<CSPValue>();
077            for (int i = 0; i < domainSize; i++) {
078                CSPValue value = new CSPValue(this, i);
079                values.add(value);
080            }
081            return values;
082        }
083    
084        @Override
085        public String getName() {
086            return "V" + getId();
087        }
088    }