.NET version of the example

As is explained in Section Using the Optimizer with BCL .NET, before accessing directly the problem held in Xpress Optimizer we need to initialize explicitly the Optimizer .NET. The cut manager callback is implemented in this .NET example by the method usrcme.

using Optimizer;
using BCL;

namespace Examples
{
  public class xbcutex
  {
      static XPRBvar[] start = new XPRBvar[4]; // Start times of jobs

      public static int usrcme(XPRSprob xprsp, object vd)
      {
          XPRBcut[] ca = new XPRBcut[2];
          XPRBprob xprbp = (XPRBprob)vd;       // Get the BCL problem
          xprbp.beginCB(xprsp);                // Coordinate BCL and Optimizer

          int num = xprsp.Nodes;
          if(num == 2)                         // Only generate cuts at node 2
          {
              ca[0] = xprbp.newCut(start[1]+2 <= start[0], 2);
              ca[1] = xprbp.newCut((4*start[2]) - (5.3*start[3]) <= -17, 2);
              System.Console.WriteLine("Adding constraints:");
              for(int i=0;i<2;i++) ca[i].print();
              if(xprbp.addCuts(ca,2) != 0)
                System.Console.WriteLine("Problem with adding cuts.");
          }
          xprbp.endCB();                       // Reset BCL to main problem
          return 0;                            // Call this function once per node
      }

      public static void Main()
      {
         XPRB.init();                          // Initialize BCL
         XPRS.Init();                          // Initialize Optimizer

         XPRBprob xprbp = new XPRBprob("Jobs");// Create a new problem
         for(int j=0;j<4;j++)                  // Create 'start' variables
           start[j] = xprbp.newVar("start");
         ...   // Define constraints and an objective function
         XPRSprob xprsp = p.getXPRSprob();     // Get Optimizer problem
         xprbp.setCutMode(1);                  // Enable the cut mode
         CutmgrCallback del = new CutmgrCallback(usrcme);
         xprsp.AddCutmgrCallback(del, (object)xprbp); // Define the cut manager callback
         xprbp.mipOptimize();                  // Solve the problem as MIP
      }
  }
}