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

using namespace std;

# include "closest_point_brute.hpp"

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

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

int main ( )

//****************************************************************************80
//
//  Purpose:
//
//    closest_point_brute_test() tests closest_point_brute().
//
//  Discussion:
//
//    We are given R, a set of NR points in M dimensions.
//
//    We are given S, a point in M dimensions.
//
//    We seek the index J of the point R(J)
//    which is nearest to S over all points in R.
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    15 August 2024
//
//  Author:
//
//    John Burkardt
//
//  Local:
//
//    int M, the spatial dimension.
//
//    int NR, the number of data points.
//
//    double R[M*NR], the data points.
//
//    double S[M], the sample point. 
//
{
  int i;
  int j;
  int m;
  double near_dist;
  int near_index;
  int nr;
  double *r;
  double *s;
  double t1;
  double t2;

  timestamp ( );
  cout << "\n";
  cout << "closest_point_brute_test():\n";
  cout << "  C++ version\n";
  cout << "  Test closest_point_brute().\n";

  m = 2;
  cout << "  Data will have spatial dimension m = " << m << "\n";
  cout << "\n";

  nr = 1;

  while ( nr <= 65536 )
  {
//
//  Generate data.
//
    r = new double[m*nr];
    for ( i = 0; i < m; i++ )
    {
      for ( j = 0; j < nr; j++ )
      {
        r[i+j*m] = drand48 ( );
      }
    }
//
//  Generate 1 sample point.
//
    s = new double[m];
    for ( i = 0; i < m; i++ )
    {
      s[i] = drand48 ( );
    }
//
//  Find closest point in R to S.
//
    t1 = cpu_time ( );
    closest_point_brute ( m, nr, r, s, near_index, near_dist );
    t2 = cpu_time ( );

    cout << "  #" << setw(5) << nr
         << "  " << setw(5) << near_index
         << "  " << setw(8) << near_dist
         << "  " << t2 - t1 << "\n";
//
//  Free memory.
//
    delete [] r;
    delete [] s;
//
//  Prepare for next loop.
//
    nr = nr * 2;
  }
//
//  Terminate.
//
  cout << "\n";
  cout << "closest_point_brute_test():\n";
  cout << "  Normal end of execution.\n";
  cout << "\n";
  timestamp ( );

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