    001package org.cpsolver.ifs.example.rpp;
    002
    003import org.cpsolver.ifs.model.Model;
    004
    005/**
    006 * RPP model. <br>
    007 * <br>
    008 * The random placement problem (RPP; for more details, see <a href=
    009 * 'http://www.fi.muni.cz/~hanka/rpp/'>http://www.fi.muni.cz/~hanka/rpp/</a>)
    010 * seeks to place a set of randomly generated rectangles (called objects) of
    011 * different sizes into a larger rectangle (called placement area) in such a way
    012 * that no objects overlap and all objects' borders are parallel to the border
    013 * of the placement area. In addition, a set of allowable placements can be
    014 * randomly generated for each object. The ratio between the total area of all
    015 * objects and the size of the placement area will be denoted as the filled area
    016 * ratio. <br>
    017 * <br>
    018 * RPP allows us to generate various instances of the problem similar to a
    019 * trivial timetabling problem. The correspondence is as follows: the object
    020 * corresponds to a course to be timetabled - the x-coordinate to its time, the
    021 * y-coordinate to its classroom. For example, a course taking three hours
    022 * corresponds to an object with dimensions 3x1 (the course should be taught in
    023 * one classroom only). Each course can be placed only in a classroom of
    024 * sufficient capacity - we can expect that the classrooms are ordered
    025 * increasingly in their size so each object will have a lower bound on its
    026 * y-coordinate.
    027 *
    028 * @author  Tomáš Müller
    029 * @version IFS 1.3 (Iterative Forward Search)<br>
    030 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
    031 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    032 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    033 * <br>
    034 *          This library is free software; you can redistribute it and/or modify
    035 *          it under the terms of the GNU Lesser General Public License as
    036 *          published by the Free Software Foundation; either version 3 of the
    037 *          License, or (at your option) any later version. <br>
    038 * <br>
    039 *          This library is distributed in the hope that it will be useful, but
    040 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    041 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    042 *          Lesser General Public License for more details. <br>
    043 * <br>
    044 *          You should have received a copy of the GNU Lesser General Public
    045 *          License along with this library; if not see
    046 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    047 */
    048public class RPPModel extends Model<Rectangle, Location> {
    049    /** Constructor. */
    050    public RPPModel() {
    051        super();
    052    }
    053
    054    /** Returns rectangle of the given name
    055     * @param name rectangle name
    056     * @return rectangle of the given name
    057     **/
    058    public Rectangle getRectangle(String name) {
    059        for (Rectangle r : variables()) {
    060            if (name.equals(r.getName()))
    061                return r;
    062        }
    063        return null;
    064    }
    065
    066}