program main

!*****************************************************************************80
!
!! test_digraph_adj_test() tests test_digraph_adj().
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    15 April 2026
!
!  Author:
!
!    John Burkardt
!
  implicit none

  call timestamp ( )
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'test_digraph_adj_test():'
  write ( *, '(a)' ) '  Fortran90 version'
  write ( *, '(a)' ) '  Test test_digraph_adj(), which returns digraphs'
  write ( *, '(a)' ) '  defined by an adjacency matrix.'

  call digraph_adj_example_abc_test ( )
  call digraph_adj_example_abcd_test ( )
  call digraph_adj_example_cycler_test ( )
  call digraph_adj_example_five_test ( )
  call digraph_adj_example_moler_test ( )
  call digraph_adj_example_sauer_test ( )
  call digraph_adj_example_sixty_test ( )
!
!  Terminate.
!
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'test_digraph_adj_test():'
  write ( *, '(a)' ) '  Normal end of execution.'
  write ( *, '(a)' ) ' '
  call timestamp ( )

  stop 0
end
subroutine digraph_adj_example_abc_test ( )

!*****************************************************************************80
!
!! digraph_adj_example_abc_test() tests digraph_adj_example_abc().
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    11 April 2026
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: node_num = 3

  integer A(node_num,node_num)

  write ( *, '(a)' ) ''
  write ( *, '(a)' ) 'abc_adjacency_test():'
  write ( *, '(a)' ) '  abc_adjacency() returns the abc digraph adjacency matrix.'

  call digraph_adj_example_abc ( A )

  call digraph_adj_print ( A, node_num, '  The abc digraph adjacency matrix' )

  return
end
subroutine digraph_adj_example_abcd_test ( )

!*****************************************************************************80
!
!! digraph_adj_example_abcd_test() tests digraph_adj_example_abcd().
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    11 April 2026
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: node_num = 4

  integer A(node_num,node_num)

  write ( *, '(a)' ) ''
  write ( *, '(a)' ) 'digraph_adj_example_abcd_test():'
  write ( *, '(a)' ) '  digraph_adj_example_abcd() returns the abcd digraph adjacency matrix.'

  call digraph_adj_example_abcd ( A )

  call digraph_adj_print ( A, node_num, '  The abcd digraph adjacency matrix' )

  return
end
subroutine digraph_adj_example_cycler_test ( )

!*****************************************************************************80
!
!! digraph_adj_example_cycler_test() tests digraph_adj_example_cycler().
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    11 April 2026
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: node_num = 9

  integer A(node_num,node_num)

  write ( *, '(a)' ) ''
  write ( *, '(a)' ) 'digraph_adj_example_cycler_test():'
  write ( *, '(a)' ) '  digraph_adj_example_cycler() returns the cycler digraph adjacency matrix.'

  call digraph_adj_example_cycler ( A )

  call digraph_adj_print ( A, node_num, '  The cycler digraph adjacency matrix' )

  return
end
subroutine digraph_adj_example_five_test ( )

!*****************************************************************************80
!
!! digraph_adj_example_five_test() tests digraph_adj_example_five().
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    11 April 2026
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: node_num = 5

  integer A(node_num,node_num)

  write ( *, '(a)' ) ''
  write ( *, '(a)' ) 'digraph_adj_example_five_test():'
  write ( *, '(a)' ) '  digraph_adj_example_five() returns the five digraph adjacency matrix.'

  call digraph_adj_example_five ( A )

  call digraph_adj_print ( A, node_num, '  The five digraph adjacency matrix' )

  return
end
subroutine digraph_adj_example_moler_test ( )

!*****************************************************************************80
!
!! digraph_adj_example_moler_test() tests digraph_adj_example_moler().
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    11 April 2026
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: node_num = 6

  integer A(node_num,node_num)

  write ( *, '(a)' ) ''
  write ( *, '(a)' ) 'digraph_adj_example_moler_test():'
  write ( *, '(a)' ) '  digraph_adj_example_moler() returns the Moler digraph adjacency matrix.'

  call digraph_adj_example_moler ( A )

  call digraph_adj_print ( A, node_num, '  The Moler digraph adjacency matrix' )

  return
end
subroutine digraph_adj_example_sauer_test ( )

!*****************************************************************************80
!
!! digraph_adj_example_sauer_test() tests digraph_adj_example_sauer().
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    11 April 2026
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: node_num = 15

  integer A(node_num,node_num)

  write ( *, '(a)' ) ''
  write ( *, '(a)' ) 'digraph_adj_example_sauer_test():'
  write ( *, '(a)' ) '  digraph_adj_example_sauer() returns the Sauer digraph adjacency matrix.'

  call digraph_adj_example_sauer ( A )

  call digraph_adj_print ( A, node_num, '  The Sauer digraph adjacency matrix' )

  return
end
subroutine digraph_adj_example_sixty_test ( )

!*****************************************************************************80
!
!! digraph_adj_example_sixty_test() tests digraph_adj_example_sixty().
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    11 April 2026
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: node_num = 12

  integer A(node_num,node_num)

  write ( *, '(a)' ) ''
  write ( *, '(a)' ) 'digraph_adj_example_sixty_test():'
  write ( *, '(a)' ) '  digraph_adj_example_sixty() returns the Sixty digraph adjacency matrix.'

  call digraph_adj_example_sixty ( A )

  call digraph_adj_print ( A, node_num, '  The Sixty digraph adjacency matrix' )

  return
end
subroutine timestamp ( )

!*****************************************************************************80
!
!! timestamp() prints the current YMDHMS date as a time stamp.
!
!  Example:
!
!    31 May 2001   9:45:54.872 AM
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    15 August 2021
!
!  Author:
!
!    John Burkardt
!
  implicit none

  character ( len = 8 ) ampm
  integer d
  integer h
  integer m
  integer mm
  character ( len = 9 ), parameter, dimension(12) :: month = (/ &
    'January  ', 'February ', 'March    ', 'April    ', &
    'May      ', 'June     ', 'July     ', 'August   ', &
    'September', 'October  ', 'November ', 'December ' /)
  integer n
  integer s
  integer values(8)
  integer y

  call date_and_time ( values = values )

  y = values(1)
  m = values(2)
  d = values(3)
  h = values(5)
  n = values(6)
  s = values(7)
  mm = values(8)

  if ( h < 12 ) then
    ampm = 'AM'
  else if ( h == 12 ) then
    if ( n == 0 .and. s == 0 ) then
      ampm = 'Noon'
    else
      ampm = 'PM'
    end if
  else
    h = h - 12
    if ( h < 12 ) then
      ampm = 'PM'
    else if ( h == 12 ) then
      if ( n == 0 .and. s == 0 ) then
        ampm = 'Midnight'
      else
        ampm = 'AM'
      end if
    end if
  end if

  write ( *, '(i2.2,1x,a,1x,i4,2x,i2,a1,i2.2,a1,i2.2,a1,i3.3,1x,a)' ) &
    d, trim ( month(m) ), y, h, ':', n, ':', s, '.', mm, trim ( ampm )

  return
end