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

using namespace std;

# include "fermat_factor.hpp"

int main ( );
void timestamp ( );

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

int main ( )

//****************************************************************************80
//
//  Purpose:
//
//    fermat_factor_test() tests fermat_factor().
//
//  Licensing:
//
//    This code is distributed under the MIT license. 
//
//  Modified:
//
//    10 April 2025
//
//  Author:
//
//    John Burkardt
//
{
  int f1;
  int f2;
  int i;
  int n;
  int n_test[4] = { 39, 25951, 2025090001, 2027651281 };

  timestamp ( );

  cout << "\n";
  cout << "fermat_factor_test():\n";
  cout << "  C++ version\n";
  cout << "  fermat_factor() factors an integer\n";
  cout << "  using the Fermat method.\n";

  for ( i = 0; i < 4; i++ )
  {
    n = n_test[i];

    fermat_factor ( n, f1, f2 );

    cout << "\n";
    cout << "  Seeking factors of n = " << n << "\n";
    cout << "  " << f1 << " * " << f2 << " = " << f1 * f2 << "\n";
  }
//
//  Terminate.
//
  cout << "\n";
  cout << "fermat_factor_test():\n";
  cout << "  Normal end of execution.\n";

  timestamp ( );

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