/* -*- mode: C++; indent-tabs-mode: nil; -*-

 *

 * This file is a part of LEMON, a generic C++ optimization library.

 *

 * Copyright (C) 2003-2008

 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

 * (Egervary Research Group on Combinatorial Optimization, EGRES).

 *

 * Permission to use, modify and distribute this software is granted

 * provided that this copyright notice appears in all copies. For

 * precise terms see the accompanying LICENSE file.

 *

 * This software is provided "AS IS" with no warranty of any kind,

 * express or implied, and with no claim as to its suitability for any

 * purpose.

 *

 */

#include "test_tools.h"

#ifdef HAVE_CONFIG_H

#include <lemon/config.h>

#endif

#ifdef HAVE_CPLEX

#include <lemon/cplex.h>

#endif

#ifdef HAVE_GLPK

#include <lemon/glpk.h>

#endif

using namespace lemon;

void solveAndCheck(MipSolver& mip, MipSolver::ProblemType stat,

                   double exp_opt) {

  using std::string;

  mip.solve();

  //int decimal,sign;

  std::ostringstream buf;

  buf << "Type should be: " << int(stat)<<" and it is "<<int(mip.type());

  //  itoa(stat,buf1, 10);

  check(mip.type()==stat, buf.str());

  if (stat ==  MipSolver::OPTIMAL) {

    std::ostringstream sbuf;

    buf << "Wrong optimal value: the right optimum is " << exp_opt;

    check(std::abs(mip.solValue()-exp_opt) < 1e-3, sbuf.str());

    //+ecvt(exp_opt,2)

  }

}

void aTest(MipSolver& mip)

{

 //The following example is very simple

  typedef MipSolver::Row Row;

  typedef MipSolver::Col Col;

  Col x1 = mip.addCol();

  Col x2 = mip.addCol();

  //Objective function

  mip.obj(x1);

  mip.max();

  //Unconstrained optimization

  mip.solve();

  //Check it out!

  //Constraints

  mip.addRow(2*x1+x2 <=2);

  mip.addRow(x1-2*x2 <=0);

  //Nonnegativity of the variable x1

  mip.colLowerBound(x1, 0);

  //Maximization of x1

  //over the triangle with vertices (0,0),(4/5,2/5),(0,2)

  double expected_opt=4.0/5.0;

  solveAndCheck(mip, MipSolver::OPTIMAL, expected_opt);

  //Restrict x2 to integer

  mip.colType(x2,MipSolver::INTEGER);

  expected_opt=1.0/2.0;

  solveAndCheck(mip, MipSolver::OPTIMAL, expected_opt);

  //Restrict both to integer

  mip.colType(x1,MipSolver::INTEGER);

  expected_opt=0;

  solveAndCheck(mip, MipSolver::OPTIMAL, expected_opt);

}

int main()

{

#ifdef HAVE_GLPK

  {

    MipGlpk mip1;

    aTest(mip1);

  }

#endif

#ifdef HAVE_CPLEX

  try {

    MipCplex mip2;

    aTest(mip2);

  } catch (CplexEnv::LicenseError& error) {

#ifdef LEMON_FORCE_CPLEX_CHECK

    check(false, error.what());

#else

    std::cerr << error.what() << std::endl;

    std::cerr << "Cplex license check failed, lp check skipped" << std::endl;

#endif

  }

#endif

  return 0;

}