function a = adj1 ( )

%*****************************************************************************80
%
%% ADJ1 returns the adjacency matrix for example 1.
%
%  Discussion:
%
%    This matrix appears on page 35 of the reference.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    04 September 2015
%
%  Author:
%
%    John Burkardt
%
%  Reference:
%
%    John MacCormick,
%    Nine Algorithms That Changed the Future: The Ingenious Ideas that 
%    Drive Today's Computers,
%    Princeton University Press,
%    ISBN-13: 978-0691158198.
%
%  Parameters:
%
%    Output, integer A(5,5), the adjacency matrix.
%
  a = zeros ( 5, 5 );

  a(1,2) = 1.0;
  a(2,5) = 1.0;
  a(3,1) = 1.0;
  a(4,1) = 1.0;
  a(5,1) = 1.0;

  return
end
