/* Compute connected components. This one does NOT use tabling but
CHEATS and uses assert. */

test :- t, d1, d2.

t :- leader(_,_),fail.
t.

:- import get_calls/3, get_returns/2 from tables.
d1 :- get_calls(leader(_,_),C,S), get_returns(C,S), tab(2), writeln(S), fail.
d1 :- writeln('-------d1 finished - d2 begins--------').

d2 :- leader(N,M),writeln([N,M]),fail.
d2.

:- dynamic visited/1.
:- index(visited/1,1,1001).
:- import ensure_dync_loaded/1 from consult.
:- ensure_dync_loaded('more_edgesP').
:- ensure_dync_loaded('nodesP').

:- table leader/2.
leader(N,M) :-
	retractall(visited(_)),
	node(N),
	(N == sts1
	 ->	true
	 ;	\+ visited(N)
	),
	reachable(N,M),assert(visited(M)).


:- table reachable/2.
reachable(L,L).
reachable(L,T) :- reachable(L,T1),(edge(T1,T);edge(T,T1)).


% make a bad edge graph.
makebad :- retractall(edge(_,_)),retractall(node(_)),
	bad(900).

bad(N) :-
	(N =:= 0
	 ->	true
	 ;	assert(node(N)),
		N1 is N-1,
		assert(edge(N1,N)),
		bad(N1)
	).