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

using namespace std;

# include "tsp_dantzig42.hpp"

int main ( );
void tsp_display ( string prefix, int n, double *x2 );
double tsp_tour_cost ( int n, double *x, int *order );
void timestamp ( );

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

int main ( )

//****************************************************************************80
//
//  Purpose:
//
//    tsp_dantzig42_test() tests tsp_dantzig42().
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    24 July 2026
//
//  Author:
//
//    John Burkardt
//
{
  double cost;
  int *dantzig42_order;
  double *dantzig42_xy;
  int i;
  int i2;
  int n;
  string prefix = "dantzig42";
  double *x2;

  timestamp ( );

  cout << "\n";
  cout << "tsp_dantzig42_test():\n";
  cout << "  C++ version\n";
  cout << "  Test tsp_dantzig42(), which returns the Dantzig 42 city\n";
  cout << "  traveling salesperson problem challenge data.\n";

  n = 42;
  dantzig42_order = tsp_dantzig42_order ( );
  dantzig42_xy = tsp_dantzig42_xy ( );

  cout << "\n";
  cout << "  City coordinates:\n";
  cout << "\n";
  for ( i = 0; i < n; i++ )
  {
    cout << "  " << setw(2) << i
         << "  " << setw(8) << dantzig42_xy[2*i]
         << "  " << setw(8) << dantzig42_xy[2*i+1] << "\n";
  }
//
//  Compute cost of shortest round trip.
//
  cost = tsp_tour_cost ( n, dantzig42_xy, dantzig42_order );
  cout << "\n";
  cout << "  Cost of round trip is " << cost << "\n";
//
//  Copy the city locations in TSP order.
//
  x2 = new double[(n+1)*2];
 
  for ( i2 = 0; i2 <= n; i2++ )
  {
    if ( i2 < n )
    {
      i = dantzig42_order[i2];
    }
    else
    {
      i = dantzig42_order[0];
    }
    x2[2*i2]   = dantzig42_xy[2*i];
    x2[2*i2+1] = dantzig42_xy[2*i+1];
  }
//
//  Display the locations.
//
  tsp_display ( prefix, n + 1, x2 );
//
//  Free memory.
//
  delete [] dantzig42_order;
  delete [] dantzig42_xy;
  delete [] x2;
//
//  Terminate.
//
  cout << "\n";
  cout << "tsp_dantzig42_test():\n";
  cout << "  Normal end of execution.\n";

  timestamp ( );

  return 0;
}
//****************************************************************************80

void tsp_display ( string prefix, int n, double *x2 )

//****************************************************************************80
//
//  Purpose:
//
//    tsp_display() plots cities and a tour connecting them.
//
//  Discussion:
//
//    If a "round trip" is desired, then the x2 array must repeat the
//    first city at the end.
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    13 June 2026
//
//  Author:
//
//    John Burkardt
//
//  Input:
//
//    string prefix: a string that defines the name of
//    the problem.  It is also used to create file names needed for
//    input to gnuplot.
//
//    int n: the number of cities.
//
//    double x[n*2]: the x and y coordinates of the cities.
//
{
  string command_filename;
  ofstream command;
  ofstream data;
  string data_filename;
  int i;
//
//  Create the data file.
//
  data_filename = prefix + "_data.txt";
  data.open ( data_filename.c_str ( ) );
  for ( i = 0; i < n; i++ )
  {
    data << x2[2*i] << "  " << x2[2*i+1] << "\n";
  }
  data.close ( );
  cout << "  Created data file '" << data_filename << "'\n";
//
//  Create the command file.
//
  command_filename = prefix + "_commands.txt";
  command.open ( command_filename.c_str ( ) );

  command << "# " << command_filename << "\n";
  command << "#\n";
  command << "# Usage:\n";
  command << "#  gnuplot < " << command_filename << "\n";
  command << "#\n";
  command << "set term png\n";
  command << "set output '" << prefix << ".png'\n";
  command << "set xlabel '<--- X --->'\n";
  command << "set ylabel '<--- Y --->'\n";
  command << "set title '" << prefix << "'\n";
  command << "set grid\n";
  command << "unset key\n";
  command << "set style data lines\n";
  command << "plot '" << data_filename 
          << "' using 1:2 lw 3 linecolor rgb 'blue', \\\n";
  command << "     '" << data_filename 
          << "' using 1:2 with points pointtype 7 pointsize 3 linecolor rgb 'green'\n";
  command << "quit\n";
  command.close ( );
  cout << "  Created command file '" << command_filename << "'\n";

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

double tsp_tour_cost ( int n, double *x, int *order )

//****************************************************************************80
//
//  Purpose:
//
//    tsp_tour_cost() evaluates the cost of a round trip.
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    18 June 2026
//
//  Author:
//
//    John Burkardt
//
//  Input:
//
//    int n: the number of cities.
//
//    double x[n,2]: the city locations.
//
//    int order[n]: the order in which the cities are visited.
//
//  Output:
//
//    double cost: the cost of the route.
//
{
  double cost;
  int from;
  int to;

  cost = 0.0;
  from = n - 1;
  for ( to = 0; to < n; to++ )
  {
    cost = cost + sqrt ( pow ( x[order[from]*2]   - x[order[to]*2],   2 )
                       + pow ( x[order[from]*2+1] - x[order[to]*2+1], 2 ) );
    from = to;
  }

  return cost;
}
//****************************************************************************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 MIT license. 
//
//  Modified:
//
//    19 March 2018
//
//  Author:
//
//    John Burkardt
//
{
# 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
}