/********************************************************
 * Xpress-BCL Java Example Problems
 * ================================
 *
 * file xbworks.java
 * `````````````````
 * Workshop planning example.
 *
 * (c) 2008-2024 Fair Isaac Corporation
 * author: S.Heipcke, Jan. 2000, rev. Mar. 2011
 ********************************************************/

import com.dashoptimization.*;

public class xbworks {
  static final int NProd = 2; /* Number of products */
  static final int NShop = 3; /* Number of workshops */
  static final int WMAX = 40; /* Maximum weekly working time */

  /****DATA****/
  static final int[][] DUR = {
    {5, 9, 7},
    {10, 2, 5}
  }; /* Duration of product p on shop s */

  static final int[] RES = {10, 8}; /* Man hours per unit */
  static final int[] PRICE = {108, 84}; /* Selling price per unit */

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

  public static void main(String[] args) {
    try (XPRBprob pb = new XPRBprob("Workshop"); /* Initialize BCL and create a new problem */
        XPRBexprContext context =
            new XPRBexprContext() /* Release XPRBexpr instances at end of block. */) {
      int p, s;
      XPRBexpr l;
      XPRBvar[] x; /* Amount of product p */

      /****VARIABLES****/
      x = new XPRBvar[NProd];
      for (p = 0; p < NProd; p++) x[p] = pb.newVar("x");

      /****OBJECTIVE****/
      l = new XPRBexpr();
      for (p = 0; p < NProd; p++) l.add(x[p].mul(PRICE[p] - 5 * RES[p]));
      pb.setObj(l); /* Set obj. function: maximize benefit */

      /****CONSTRAINTS****/
      for (s = 0; s < NShop; s++) {
          /* Limit on weekly working hours */
        l = new XPRBexpr();
        for (p = 0; p < NProd; p++) l.add(x[p].mul(DUR[p][s]));
        pb.newCtr("ResMax", l.lEql(WMAX));
      }

      /****SOLVING + OUTPUT****/
      pb.setSense(XPRB.MAXIM);
      pb.lpOptimize(""); /* Solve the LP-problem */
      System.out.println("Objective: " + pb.getObjVal()); /* Get objective value */
      for (p = 0; p < NProd; p++) /* Print the solution values */
        System.out.print(x[p].getName() + ":" + x[p].getSol() + " ");
      System.out.println();
    }
  }
}