# include <cmath>
# include <ctime>
# include <cstdlib>
# include <iomanip>
# include <iostream>
#
using namespace std;
#
# include "middle_square.hpp"

int main ( );
void middle_square_next_test ( );
void timestamp ( );

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

int main ( )

//****************************************************************************80
//
//  Purpose:
//
//    middle_square_test() tests middle_square().
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    16 September 2022
//
//  Author:
//
//    John Burkardt
//
{
  timestamp ( );
  cout << "\n";
  cout << "middle_square_test():\n";
  cout << "  C version\n";
  cout << "  Test middle_square()\n";

  middle_square_next_test ( );
//
//  Terminate.
//
  cout << "\n";
  cout << "middle_square_test():\n";
  cout << "  Normal end of execution.\n";
  cout << "\n";
  timestamp ( );

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

void middle_square_next_test ( )

//****************************************************************************80
//
//  Purpose:
//
//    middle_square_next_test() tests middle_square_next().
//
//  Discussion:
//
//    This function simply demonstrates the results of 10 successive calls
//    to middle_square_next(), for a range of values of d.
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    16 September 2022
//
//  Author:
//
//    John Burkardt
//
{
  long long int d;
  long long int divisor;
  long long int i;
  long long int s;

  cout << "\n";
  cout << "middle_square_next_test():\n";
  cout << "  middle_square_next ( s, d ) applies the middle square algorithm\n";
  cout << "  using a 2*d digit seed.\n";

  for ( d = 1; d <= 5; d++ )
  {
    cout << "\n";
    cout << "  Using d = " << d << "\n";
    cout << "\n";

    divisor = ( long long int ) pow ( 10, 2 * d );
    s = ( 2147483647 % divisor );

    for ( i = 0; i <= 10; i++ )
    {
      cout << "  " << i << "  " << s << "\n";
      s = middle_square_next ( s, d );
    }
  }

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