001package net.sf.cpsolver.ifs.example.csp;
002
003import java.util.ArrayList;
004import java.util.List;
005import java.util.Random;
006
007import 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 Tomáš Müller<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 */
033public 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}