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

using namespace std;

# include "closest_pair_brute.hpp"

int main ( );
double closest_pair_brute_test01 ( int n );
double cpu_time ( );
void timestamp ( );

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

int main ( )

//****************************************************************************80
//
//  Purpose:
//
//    closest_pair_brute_test() tests closest_pair_brute().
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    03 April 2024
//
//  Author:
//
//    John Burkardt
//
{
  int i;
  int nvec[8] = 
    { 100, 200, 400, 800, 1600, 3200, 6400, 12800 };
  double svec[8];

  timestamp ( );
  cout << "\n";
  cout << "closest_pair_brute_test()\n";
  cout << "  C++ version\n";
  cout << "  Test closest_pair_brute().\n";
//
//  Solve a sequence of problems of increasing size N.
//
  for ( i = 0; i < 8; i++ )
  {
    svec[i] = closest_pair_brute_test01 ( nvec[i] );
  }
//
//  Print the final table.
//
  cout << "\n";
  cout << "  Test  Points  Time\n";
  cout << "\n";
  for ( i = 0; i < 8; i++ )
  {
    cout << "  " << setw(4) << i
         << "  " << setw(6) << nvec[i]
         << "  " << setw(14) << svec[i] << "\n";
  }
/*
  Terminate.
*/
  cout << "\n";
  cout << "closest_pair_brute_test():\n";
  cout << "  Normal end of execution.\n";
  cout << "\n";
  timestamp ( );

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

double closest_pair_brute_test01 ( int n )

//****************************************************************************80
/*
  Purpose:

    closest_pair_brute_test01() tests the closest_pair_brute program.

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    03 April 2024

  Author:

    John Burkardt

  Input:

    int n: the number of points.

  Output:

    double s: execution time in seconds.
*/
{
  double d;
  int i;
  int j;
  double s;
  long int seed;
  double *xy;

  cout << "\n";
  cout << "closest_pair_brute_test01():\n";
  cout << "  closest_pair_brute() on a set of N points in 2D.\n";

  xy = new double[n*2];

  seed = 123456789L;
  srand48 ( seed );

  for ( j = 0; j <= 1; j++ )
  {
    for ( i = 0; i <= n; i++ )
    {
      xy[i+j*n] = drand48 ( );
    }
  }

  s = cpu_time ( );
  closest_pair_brute ( n, xy, d, i, j );
  s = cpu_time ( ) - s;

  cout << "\n";
  cout << "  n = " << n << "\n";
  cout << "  time in seconds = " << s << "\n";
  cout << "  xy(" << i << ") = (" << xy[i+0*n] << "," << xy[i+1*n] << ")\n";
  cout << "  xy(" << j << ") = (" << xy[j+0*n] << "," << xy[j+1*n] << ")\n";
  cout << "  distance = " << d << "\n";

  delete [] xy;

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

double cpu_time ( )

//****************************************************************************80
//
//  Purpose:
//
//    cpu_time() returns the current reading on the CPU clock.
//
//  Discussion:
//
//    The CPU time measurements available through this routine are often
//    not very accurate.  In some cases, the accuracy is no better than
//    a hundredth of a second.  
//
//  Licensing:
//
//    This code is distributed under the MIT license. 
//
//  Modified:
//
//    06 June 2005
//
//  Author:
//
//    John Burkardt
//
//  Output:
//
//    double cpu_time(): the current reading of the CPU clock, in seconds.
//
{
  double value;

  value = ( double ) clock ( ) 
        / ( double ) CLOCKS_PER_SEC;

  return value;
}
//****************************************************************************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
}