function ADJ = graph_arc_to_graph_adj ( inode, jnode )

%*****************************************************************************80
%
%% graph_arc_to_graph_adj() converts an arc list graph to an adjacency graph.
%
%  Licensing:
%
%    This code is distributed under the MIT license. 
%
%  Modified:
%
%    10 April 2026
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    integer INODE(edge_num), JNODE(edge_num), the edge array for 
%    an undirected graph.  The I-th edge connects nodes INODE(I) and JNODE(I).
%
%  Output:
%
%    integer ADJ(node_num,node_num), the adjacency information.
%
  edge_num = length ( inode );
  node_num = max ( max ( inode ), max ( jnode ) );

  ADJ = zeros ( node_num, node_num );

  for edge_id = 1 : edge_num
    i = inode(edge_id);
    j = jnode(edge_id);
    ADJ(i,j) = 1;
  end

  return
end
