program big_ints
!
!***********************************************************************
!
!! BIG_INTS demonstrates how to set up integers with a bigger range.
!
!
!  Modified:
!
!    11 April 2001
!
!  Author:
!
!    John Burkardt
!
  implicit none
!
  call timestamp ( )

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'BIG_INTS'
  write ( *, '(a)' ) '  Demonstrate the use of "big" integers.'

  call test01
  call test02

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'BIG_INTS'
  write ( *, '(a)' ) '  Normal end of execution.'

  stop
end
subroutine test01
!
!***********************************************************************
!
!! TEST01 shows what you get by default.
!
  implicit none
!
  integer i1
!
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'TEST01'
  write ( *, '(a)' ) '  Use integers of the default type.'
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  HUGE() returns the largest value of the given type.'
  write ( *, '(a,i12)' ) '    HUGE(I1) = ', huge ( i1 )
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  RANGE provides the decimal exponent range.'
  write ( *, '(a,i12)' ) '    RANGE(I1) = ', range(i1)
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  KIND returns the "kind" of a given integer.'
  write ( *, '(a,i12)' ) '    KIND(I1) = ', kind(i1)

  return
end
subroutine test02
!
!***********************************************************************
!
!! TEST02 shows what you get with KIND = 8.
!
  implicit none
!
  integer ( kind = 8 ) i1
!
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'TEST02'
  write ( *, '(a)' ) '  Use integers of KIND = 8.'
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  HUGE() returns the largest value of the given type.'
  write ( *, '(a,i24)' ) '    HUGE(I1) = ', huge ( i1 )
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  RANGE provides the decimal exponent range.'
  write ( *, '(a,i12)' ) '    RANGE(I1) = ', range(i1)
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  KIND returns the "kind" of a given integer.'
  write ( *, '(a,i12)' ) '    KIND(I1) = ', kind(i1)

  return
end
subroutine timestamp ( )
!
!*******************************************************************************
!
!! TIMESTAMP prints the current YMDHMS date as a time stamp.
!
!
!  Example:
!
!    May 31 2001   9:45:54.872 AM
!
!  Modified:
!
!    31 May 2001
!
!  Author:
!
!    John Burkardt
!
!  Parameters:
!
!    None
!
  implicit none
!
  character ( len = 8 ) ampm
  integer d
  character ( len = 8 ) date
  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
  character ( len = 10 )  time
  integer values(8)
  integer y
  character ( len = 5 ) zone
!
  call date_and_time ( date, time, zone, 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 ( *, '(a,1x,i2,1x,i4,2x,i2,a1,i2.2,a1,i2.2,a1,i3.3,1x,a)' ) &
    trim ( month(m) ), d, y, h, ':', n, ':', s, '.', mm, trim ( ampm )

  return
end