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

using namespace std;

# include "vector.hpp"

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

void vector ( int *x_in, int *x_out )

//****************************************************************************80
//
//  Purpose:
//
//    vector() stores, saves, and returns a vector x of 3 entries.
//
//  Discussion:
//
//    vector ( x_in, NULL )
//      copies the values in x_in into the internal vector x_default.
//
//    vector ( NULL, x_out )
//      copies the values in x_default into the output vector x_out.
//
//    vector ( x_in, x_out )
//      copies the values in x_in into the internal vector x_default,
//      and returns these same value in the output vector x_out.
//
//    vector ( NULL, NULL )
//      prints the values in x_default.
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    11 October 2025
//
//  Author:
//
//    John Burkardt
//
//  Input:
//
//    int *X_IN: NULL or the address of X.
//
//  Output:
//
//    int *X_OUT: the current value of X.
//
//  Local:
//
//    int *X_DEFAULT: the internal value of X.
//
//
{
  int i;
  static int x_default[3] = { 1, 2, 3 };
//
//  New values, if supplied on input, overwrite the current values.
//
  if ( x_in )
  {
    for ( i = 0; i < 3; i++ )
    {
      x_default[i] = x_in[i];
    }
  }
//
//  The current values are copied to the output.
//
  if ( x_out )
  {
    for ( i = 0; i < 3; i++ )
    {
      x_out[i] = x_default[i];
    }
  }
//
//  As a check, print current items.
//  In practice, this code would do its work silently.
//
  if ( x_in )
  {
    cout << "  x_in = ( " << x_in[0] << ", " 
                          << x_in[1] << ", "
                          << x_in[2] << ")\n";
  }
  else
  {
    cout << "  x_in = NULL\n";
  }

  if ( x_out )
  {
    cout << "  x_out = ( " << x_out[0] << ", " 
                           << x_out[1] << ", "
                           << x_out[2] << ")\n";
  }
  else
  {
    cout << "  x_out = NULL\n";
  }

  cout << "  x_default = ( " << x_default[0] << ", " 
                             << x_default[1] << ", "
                             << x_default[2] << ")\n";

  return;
}