# include <stdio.h>
# include <stdlib.h>
# include <time.h>

# include "fermat_factor.h"

int main ( );
void timestamp ( );

/******************************************************************************/

int main ( )

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

    fermat_factor_test() tests fermat_factor().

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    09 April 2025

  Author:

    John Burkardt
*/
{
  int f1;
  int f2;
  int i;
  int n;
  int n_test[4] = { 39, 25951, 2025090001, 2027651281 };

  timestamp ( );

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

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

    fermat_factor ( n, &f1, &f2 );

    printf ( "\n" );
    printf ( "  Seeking factors of n = %d\n", n );
    printf ( "  %d * %d = %d\n", f1, f2, f1 * f2 );
  }
/*
  Terminate.
*/
  printf ( "\n" );
  printf ( "fermat_factor_test():\n" );
  printf ( "  Normal end of execution.\n" );

  timestamp ( );

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

void timestamp ( )

/******************************************************************************/
/*
  Purpose:
 
    timestamp() prints the current YMDHMS date as a time stamp.

  Example:

    17 June 2014 09:45:54 AM

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    01 May 2021

  Author:

    John Burkardt
*/
{
# define TIME_SIZE 40

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

  now = time ( NULL );
  tm = localtime ( &now );

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

  printf ( "%s\n", time_buffer );

  return;
# undef TIME_SIZE
}