# include <cstdlib>
# include <ctime>
# include <fstream>
# include <iomanip>
# include <iostream>

using namespace std;

# include "polyomino_lp_write.hpp"

//****************************************************************************80

void polyomino_lp_write ( string filename, string label, int m, int n, int a[], 
  int b[] )

//****************************************************************************80
//
//  Purpose:
//
//    POLYOMINO_LP_WRITE writes an LP file for the polyomino problem.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    17 May 2018
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, string FILENAME, the output filename.
//
//    Input, string LABEL, the problem title.
//
//    Input, int M, the number of equations
//
//    Input, int N, the number of variables.
//
//    Input, int A[M*N], the coefficients.
//
//    Input, int B[M], the right hand sides.
//
{
  bool first;
  int i;
  int j;
  ofstream output;
//
//  Open the file.
//
  output.open ( filename.c_str ( ) );

  if ( ! output ) 
  {
    cerr << "\n";
    cerr << "POLYOMINO_LP_WRITE - Error!\n";
    cerr << "  Could not open the output file.\n";
    exit ( 1 );
  }

  output << label << "\n";
  output << "\n";

  output << "Maximize\n";
  output << "  Obj: 0\n";

  output << "Subject to\n";

  for ( i = 0; i < m; i++ )
  {
    first = true;
    for ( j = 0; j< n; j++ )
    {
      if ( a[i+j*m] != 0 )
      {
        if ( a[i+j*m] < 0 )
        {
          output << " -";
        }
        else if ( ! first )
        {
          output << " +";
        }

        if ( abs ( a[i+j*m] ) == 1 )
        {
          output << " x" << j + 1;
        }
        else
        {
          output << " " <<  abs ( a[i+j*m] ) << " x" << j + 1;
        }
        first = false;
      }
    }
    output << " = " << b[i] << "\n";
  }

  output << "Binary\n";
  output << " ";
  for ( j = 0; j < n; j++ )
  {
    output << " x" << j + 1;
  }
  output << "\n";

  output << "End\n";
//
//  Close the file.
//
  output.close ( );

  return;
}
//****************************************************************************80

void timestamp ( )

//****************************************************************************80
//
//  Purpose:
//
//    TIMESTAMP prints the current YMDHMS date as a time stamp.
//
//  Example:
//
//    31 May 2001 09:45:54 AM
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license. 
//
//  Modified:
//
//    19 March 2018
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    None
//
{
# define TIME_SIZE 40

  static char time_buffer[TIME_SIZE];
  const struct std::tm *tm_ptr;
  std::time_t now;

  now = std::time ( NULL );
  tm_ptr = std::localtime ( &now );

  std::strftime ( time_buffer, TIME_SIZE, "%d %B %Y %I:%M:%S %p", tm_ptr );

  std::cout << time_buffer << "\n";

  return;
# undef TIME_SIZE
}