This example shows you how to solve a MIP with the Component Libraries when the problem data is stored in a file.

Complete Program: ilomipex2.cpp

This example derives from ilolpex2.cpp, an LP example explained in the manual ILOG CPLEX Getting Started. That LP example differs from this MIP example in these ways:

Like other applications based on ILOG CPLEX Concert Technology, this one uses IloEnv env to initialize the Concert Technology environment and IloModel model(env) to create a problem object. Before it ends, it calls env.end to free the environment.

// File: examples/src/ilomipex2.cpp 
// Version 9.0    
// --------------------------------------------------------------------------
//  Copyright (C) 1999-2003 by ILOG.
//  All Rights Reserved.
//  Permission is expressly granted to use this example in the
//  course of developing applications that use ILOG products.
// --------------------------------------------------------------------------
//
// ilomipex2.cpp - Reading in and optimizing a problem
//
// To run this example, command line arguments are required.
// i.e.,   ilomipex2   filename
//
// Example:
//     ilomipex2  mexample.mps
//

#include <ilcplex/ilocplex.h>
ILOSTLBEGIN

static void usage (const char *progname);

int
main (int argc, char **argv)
{
   IloEnv env;
   try {
      IloModel model(env);
      IloCplex cplex(env);

      if ( argc != 2 ) {
         usage (argv[0]);
         throw(-1);
      }

      IloObjective   obj;
      IloNumVarArray var(env);
      IloRangeArray  rng(env);
      cplex.importModel(model, argv[1], obj, var, rng);

      cplex.extract(model);
      cplex.solve();

      env.out() << "Solution status = " << cplex.getStatus() << endl;
      env.out() << "Solution value  = " << cplex.getObjValue() << endl;

      IloNumArray vals(env);
      cplex.getValues(vals, var);
      env.out() << "Values        = " << vals << endl;
   }
   catch (IloException& e) {
      cerr << "Concert exception caught: " << e << endl;
   }
   catch (...) {
      cerr << "Unknown exception caught" << endl;
   }

   env.end();
   return 0;
}  // END main


static void usage (const char *progname)
{
   cerr << "Usage: " << progname << " filename" << endl;
   cerr << "   where filename is a file with extension " << endl;
   cerr << "      MPS, SAV, or LP (lower case is allowed)" << endl;
   cerr << " Exiting..." << endl;
} // END usage