001package org.cpsolver.ifs.assignment;
002
003import java.util.ArrayList;
004import java.util.Arrays;
005import java.util.Collection;
006import java.util.List;
007
008import org.cpsolver.ifs.assignment.context.AssignmentContextHolder;
009import org.cpsolver.ifs.model.Value;
010import org.cpsolver.ifs.model.Variable;
011
012
013/**
014 * An assignment using array to store values of all the variables of the model.
015 * {@link Variable#getIndex()} is used to index the array.
016 * 
017 * @see Assignment
018 * 
019 * @author  Tomáš Müller
020 * @version IFS 1.3 (Iterative Forward Search)<br>
021 *          Copyright (C) 2014 Tomáš Müller<br>
022 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
023 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
024 * <br>
025 *          This library is free software; you can redistribute it and/or modify
026 *          it under the terms of the GNU Lesser General Public License as
027 *          published by the Free Software Foundation; either version 3 of the
028 *          License, or (at your option) any later version. <br>
029 * <br>
030 *          This library is distributed in the hope that it will be useful, but
031 *          WITHOUT ANY WARRANTY; without even the implied warranty of
032 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
033 *          Lesser General Public License for more details. <br>
034 * <br>
035 *          You should have received a copy of the GNU Lesser General Public
036 *          License along with this library; if not see <a href='http://www.gnu.org/licenses'>http://www.gnu.org/licenses</a>.
037 * @param <V> Variable
038 * @param <T> Value
039 **/
040public class AssignmentArray<V extends Variable<V, T>, T extends Value<V, T>> extends AssignmentAbstract<V, T> {
041    protected Object[] iAssignments = new Object[1000];
042    protected Long[] iIteration = new Long[1000];
043    
044    /** Creates an empty assignment 
045     * @param contexts assignment context holder
046     **/
047    public AssignmentArray(AssignmentContextHolder<V, T> contexts) {
048        super(contexts);
049    }
050    
051    @Override
052    public long getIteration(V variable) {
053        try {
054            Long it = iIteration[variable.getIndex()];
055            return (it == null ? 0 : it);
056        } catch (ArrayIndexOutOfBoundsException e) {
057            return 0;
058        }
059    }
060    
061    @Override
062    @SuppressWarnings("unchecked")
063    protected T getValueInternal(V variable) {
064        try {
065            return (T) iAssignments[variable.getIndex()];
066        } catch (ArrayIndexOutOfBoundsException e) {
067            return null;
068        }
069    }
070
071    @Override
072    protected void setValueInternal(long iteration, V variable, T value) {
073        if (iAssignments.length <= variable.getIndex()) {
074            iAssignments = Arrays.copyOf(iAssignments, variable.getIndex() + 1000);
075            iIteration = Arrays.copyOf(iIteration, variable.getIndex() + 1000);
076        }
077        if (value == null) {
078            iAssignments[variable.getIndex()] = null;
079            iIteration[variable.getIndex()] = null;
080        } else {
081            iAssignments[variable.getIndex()] = value;
082            if (iteration > 0)
083                iIteration[variable.getIndex()] = iteration;
084        }
085    }
086    
087    @Override
088    @SuppressWarnings("unchecked")
089    public Collection<V> assignedVariables() {
090        List<V> variables = new ArrayList<V>(iAssignments.length);
091        for (Object value: iAssignments)
092            if (value != null) variables.add(((T)value).variable());
093        return variables;
094    }
095    
096    @Override
097    @SuppressWarnings("unchecked")
098    public Collection<T> assignedValues() {
099        List<T> values = new ArrayList<T>(iAssignments.length);
100        for (Object value: iAssignments)
101            if (value != null) values.add((T)value);
102        return values;
103    }
104
105    @Override
106    public int nrAssignedVariables() {
107        int ret = 0;
108        for (Object value: iAssignments)
109            if (value != null) ret ++;
110        return ret;
111    }
112}