Setops - Index sets

/********************************************************
 * Xpress-BCL Java Example Problems
 * ================================
 *
 * file xbsetops.java
 * ``````````````````
 * Set operations.
 *
 * (c) 2008-2024 Fair Isaac Corporation
 * author: S.Heipcke, Jan. 2000
 ********************************************************/

import com.dashoptimization.*;

public class xbsetops {

  /* Define arrays with index names: note that the restriction
  to 8 characters does not apply for BCL                    */
  static final String city_names[] = {"rome", "bristol", "london", "paris", "liverpool"};
  static final String port_names[] = {
    "plymouth", "bristol", "glasgow",
    "london", "calais", "liverpool"
  };

  /***********************************************************************/

  /**** Create the union of two index sets ****/
  static XPRBindexSet createUnion(XPRBprob p, XPRBindexSet a, XPRBindexSet b, String name) {
    int i;
    XPRBindexSet c;

    c = p.newIndexSet(name, a.getSize() + b.getSize());
    for (i = 0; i < a.getSize(); i++) c.addElement(a.getIndexName(i));
    for (i = 0; i < b.getSize(); i++) c.addElement(b.getIndexName(i));
    return c;
  }

  /**** Create the intersection of two index sets ****/
  static XPRBindexSet createInter(XPRBprob p, XPRBindexSet a, XPRBindexSet b, String name) {
    int i;
    XPRBindexSet c;

    c = p.newIndexSet(name, a.getSize() < b.getSize() ? a.getSize() : b.getSize());
    for (i = 0; i < a.getSize(); i++)
      if (b.getIndex(a.getIndexName(i)) >= 0) c.addElement(a.getIndexName(i));
    return c;
  }

  /***********************************************************************/

  public static void main(String[] args) {
    XPRBindexSet ports, cities, both, places;
    int i;

    try (XPRBprob p = new XPRBprob("Setops")) {
        /* Initialize BCL and create a new problem */

      /* Create sets "cities" and "ports" and add the indices */
      cities = p.newIndexSet("cities", city_names.length);
      for (i = 0; i < city_names.length; i++) cities.addElement(city_names[i]);
      ports = p.newIndexSet("ports", port_names.length);
      for (i = 0; i < port_names.length; i++) ports.addElement(port_names[i]);

      /* Create the union of "cities" and "ports" and print it */
      places = createUnion(p, cities, ports, "places");
      places.print();
      /* Create the intersection of "cities" and "ports", print it */
      both = createInter(p, cities, ports, "both sets");
      both.print();
    }
  }
}