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cgal/QP_solver/examples/QP_solver/integer_qp_solver.cpp
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// Copyright (c) 1997-2001 ETH Zurich (Switzerland).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you may redistribute it under
// the terms of the Q Public License version 1.0.
// See the file LICENSE.QPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL$
// $Id$
//
//
// Author(s) : Kaspar Fischer <fischerk@inf.ethz.ch>
// Bernd Gaertner <gaertner@inf.ethz.ch>
#include <iostream>
#include <sstream>
#include <cstdlib>
#include <CGAL/QP_solver/gmp_double.h>
#include <CGAL/QP_solver.h>
#include <CGAL/QP_solver/QP_full_exact_pricing.h>
#include <CGAL/QP_solver/QP_partial_exact_pricing.h>
#include <CGAL/QP_solver/QP_full_filtered_pricing.h>
#include <CGAL/QP_solver/QP_partial_filtered_pricing.h>
#include <CGAL/QP_solver/Double.h>
#include <CGAL/Gmpq.h>
#include <CGAL/Gmpz.h>
#include <CGAL/QP_solver/MPS.h> // should to into QP_solver.h (?)
int main(const int argNr,const char **args) {
using std::cout;
using std::endl;
using CGAL::Tag_true;
using CGAL::Tag_false;
// get desired level of additional logging output:
const int verbosity = argNr < 2? 1 : std::atoi(args[1]);
// construct QP instance:
typedef CGAL::Gmpz IT;
typedef CGAL::Gmpz ET;
typedef CGAL::QP_MPS_instance<IT,ET> QP;
QP qp(std::cin,true,verbosity);
// check for format errors in MPS file:
if (!qp.is_valid()) {
cout << "Input is not a valid MPS file." << endl
<< "Error: " << qp.error() << endl;
std::exit(2);
}
if (verbosity > 0) {
cout << endl << qp << endl;
}
typedef Tag_false Is_linear; // is the instance known in advance to be an LP?
typedef Tag_false Is_symmetric; // is the D matrix known to be symmetric?
typedef Tag_false Has_equalities_only_and_full_rank; // (see manual)
typedef Tag_false Is_in_standard_form; // (see manual)?
// in case of an LP, zero the D matrix:
// (Note: if you know in advance that the problem is an LP
// you should not do this, but set Is_linear to Tag_true.)
if (qp.is_linear() && !check_tag(Is_linear()))
qp.make_zero_D();
typedef CGAL::QP_solver_MPS_traits_d<QP,
Is_linear,
Is_symmetric,
Has_equalities_only_and_full_rank,
Is_in_standard_form> Traits;
CGAL::QP_pricing_strategy<Traits> *strategy = 0;
// new CGAL::QP_partial_filtered_pricing<Traits,IT>;
typedef CGAL::QP_solver<Traits> Solver;
Solver solver(qp.number_of_variables(),
qp.number_of_constraints(),
qp.A(),qp.b(),qp.c(),
qp.D(),
qp.row_types(),
qp.fl(),qp.l(),qp.fu(),qp.u(),
strategy,
verbosity);
if (solver.is_valid()) {
cout << "Solution is valid." << endl;
} else {
cout << "Solution is not valid!" << endl;
return 1;
}
// get solution:
if (solver.status() == Solver::OPTIMAL) {
// output solution:
cout << "Objective function value: " <<
solver.solution() << " ~ " <<
CGAL::to_double(solver.solution_numerator()) /
CGAL::to_double(solver.solution_denominator()) <<
endl;
cout << "Variable values:" << endl;
Solver::Variable_value_iterator it
= solver.variables_value_begin() ;
Solver::Variable_numerator_iterator it_n
= solver.variables_numerator_begin();
ET denom = solver.variables_common_denominator();
for (unsigned int i=0; i < qp.number_of_variables(); ++it, ++it_n, ++i)
cout << " " << qp.name_of_variable(i) << " = "
<< *it << " ~ " << CGAL::to_double(*it_n)/CGAL::to_double(denom)
<< endl;
return 0;
}
if (solver.status() == Solver::INFEASIBLE)
cout << "Problem is infeasible." << endl;
else // unbounded
cout << "Problem is unbounded." << endl;
return 0;
}