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cycles_johnson_abate
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iterative and functional cycle code outputs correct results

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josch 12 years ago
parent 054604d5cf
commit fa78ca1a30
2 changed files with 92 additions and 106 deletions
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96
cycles_functional.ml
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@ -9,7 +9,7 @@ module SV = Set.Make(G.V)
let to_set l = List.fold_right SV.add l SV.empty ;;
let partition s w = snd(SV.partition (fun e -> e >= w) s);;
let partition s w = fst(SV.partition (fun e -> e >= w) s);;
let print_set s =
String.join " " (List.map (fun e ->
@ -51,17 +51,11 @@ let init_block g =
t
;;
let get_notelem t n =
Hashtbl.find t.notelem n
;;
let rec unblock t n =
Printf.eprintf "unblock %d\n" (G.V.label n);
if Hashtbl.find t.blocked n then begin
Hashtbl.replace t.blocked n false;
let l = get_notelem t n in
List.iter (unblock t) l;
Hashtbl.replace t.notelem n []
List.iter (unblock t) (Hashtbl.find t.notelem n);
Hashtbl.replace t.notelem n [];
end
;;
@ -69,10 +63,6 @@ let block t n =
Hashtbl.replace t.blocked n true
;;
let is_bloked t n =
Hashtbl.find t.blocked n
;;
let find_all_cycles_johnson g =
if not G.is_directed then
assert false;
@ -85,76 +75,76 @@ let find_all_cycles_johnson g =
Stack.push thisnode path;
block t thisnode;
let (closed,result) =
let (closed,result) =
G.fold_succ (fun nextnode (c,r) ->
Printf.eprintf "startnode %d\n" (G.V.label startnode);
Printf.eprintf "nextnode %d\n" (G.V.label nextnode);
if G.V.equal nextnode startnode then begin
Printf.eprintf "closed = true 1\n";
(true,(Stack.copy path)::r)
end else begin
if not(is_bloked t nextnode) then
circuit t r nextnode startnode component
else
(true, (stack_to_list path)::r)
end else begin
if not(Hashtbl.find t.blocked nextnode) then begin
let c2, r2 = circuit t r nextnode startnode component in
(c || c2, r2)
end else
(c,r)
end
end
) component thisnode (false,result)
in
if closed then begin
Printf.eprintf "closed = true 3\n";
unblock t thisnode
end else
G.iter_succ (fun nextnode ->
let l = get_notelem t nextnode in
if List.mem thisnode l then
let l = Hashtbl.find t.notelem nextnode in
if not(List.mem thisnode l) then
Hashtbl.replace t.notelem nextnode (thisnode::l)
) component thisnode;
ignore(Stack.pop path);
(closed,result)
(closed, result)
in
(* Johnson's algorithm requires some ordering of the nodes. *)
let vertex_set = G.fold_vertex SV.add g SV.empty in
Printf.eprintf "inital vertex set %s\n" (print_set vertex_set);
SV.fold (fun s result ->
let result = SV.fold (fun s result ->
(* Build the subgraph induced by s and following nodes in the ordering *)
Printf.eprintf "selected element %d\n" (G.V.label s);
let subset = SV.add s (partition vertex_set s) in
Printf.eprintf "subset %s\n" (print_set subset);
let subgraph = extract_subgraph g subset in
if G.nb_edges subgraph > 0 then begin
(* Find the strongly connected component in the subgraph
* that contains the least node according to the ordering *)
let scc = G.Components.scc_list subgraph in
let minnode = SV.min_elt subset in
Printf.eprintf "minnode %d\n" (G.V.label minnode);
let mincomp = List.find (fun l -> List.mem minnode l) scc in
Printf.eprintf "mincomp %s\n" (print_set ((to_set mincomp)));
(* smallest node in the component according to the ordering *)
let startnode = minnode in
let component = extract_subgraph subgraph (to_set mincomp) in
(* Find the strongly connected component in the subgraph
* that contains the least node according to the ordering *)
let scc = G.Components.scc_list subgraph in
let minnode = SV.min_elt subset in
let mincomp = List.find (fun l -> List.mem minnode l) scc in
G.dot_output component (Printf.sprintf "test-component%d.dot" (G.V.label s));
(* smallest node in the component according to the ordering *)
let component = extract_subgraph subgraph (to_set mincomp) in
if G.nb_edges component > 0 then begin
(* init the block table for this component *)
let t = init_block component in
snd(circuit t result startnode startnode component);
end else begin
Printf.eprintf "No edges to consider\n";
snd(circuit t result minnode minnode component);
end else
result
end
) vertex_set []
in
List.rev result
;;
let g = G.Rand.graph ~v:5 ~e:10 () in
G.dot_output g "test.dot";
if Array.length Sys.argv < 3 then begin
Printf.printf "usage: %s num_vertices [v1,v2...]\n" Sys.argv.(0);
exit 1;
end;
let v = int_of_string (Sys.argv.(1)) in
let g = G.create ~size:v () in
let a = Array.init v G.V.create in
for i = 2 to Array.length Sys.argv - 1 do
let v1, v2 = String.split Sys.argv.(i) "," in
G.add_edge g a.(int_of_string v1) a.(int_of_string v2);
done;
let ll = find_all_cycles_johnson g in
List.iter (fun path ->
let path = stack_to_list path in
Printf.printf "path : %s\n"
Printf.printf "%s\n"
(String.join " " (List.map (fun e -> string_of_int (G.V.label e)) path))
) ll

102
cycles_iter.ml
Unescape Escape View File

@ -17,52 +17,48 @@ let find_all_cycles_johnson g =
(* list to accumulate the circuits found *)
let result = ref [] in
let rec circuit thisnode startnode component =
let stack_to_list s =
let l = ref [] in
Stack.iter (fun e -> l:= e::!l) s;
!l
in
let rec unblock n =
if Hashtbl.find blocked n then begin
Hashtbl.replace blocked n false;
List.iter unblock (Hashtbl.find b n);
Hashtbl.replace b n [];
end
in
let rec unblock thisnode =
Printf.eprintf "unblock %d\n" (G.V.label thisnode);
if Hashtbl.find blocked thisnode then begin
Hashtbl.replace blocked thisnode false;
List.iter unblock (Hashtbl.find b thisnode);
Hashtbl.replace b thisnode []
end
in
let stack_to_list s =
let l = ref [] in
Stack.iter (fun e -> l:= e::!l) s;
!l
in
let rec circuit thisnode startnode component =
let closed = ref false in
Stack.push thisnode path;
Hashtbl.replace blocked thisnode true;
G.iter_succ (fun nextnode ->
Printf.eprintf "startnode %d\n" (G.V.label startnode);
Printf.eprintf "nextnode %d\n" (G.V.label nextnode);
if G.V.equal nextnode startnode then begin
result := ((stack_to_list path))::!result;
closed := true;
Printf.eprintf "closed = true 1\n";
end else begin if not(Hashtbl.find blocked nextnode) then
if circuit nextnode startnode component then begin
closed := true;
Printf.eprintf "closed = true 2\n";
end
end
) component thisnode;
if !closed then begin
Printf.eprintf "closed = true 3\n";
unblock thisnode
end
else
G.iter_succ (fun nextnode ->
if List.mem thisnode (Hashtbl.find b nextnode) then
Hashtbl.replace b nextnode (thisnode::(Hashtbl.find b nextnode))
let l = Hashtbl.find b nextnode in
if not(List.mem thisnode l) then
Hashtbl.replace b nextnode (thisnode::l)
) component thisnode;
ignore(Stack.pop path);
!closed
in
let module SV = Set.Make(G.V) in
let subgraph_ g s =
let extract_subgraph g s =
let sg = G.create () in
G.iter_edges (fun v1 v2 ->
if SV.mem v1 s then G.add_vertex sg v1;
@ -77,47 +73,47 @@ let find_all_cycles_johnson g =
*)
let to_set l = List.fold_right SV.add l SV.empty in
let vertex_set = G.fold_vertex SV.add g SV.empty in
let part s w = snd(SV.partition (fun e -> e >= w) s) in
let print_set s =
String.join " " (List.map (fun e ->
string_of_int (G.V.label e)
) (SV.elements s))
in
Printf.eprintf "inital set %s\n" (print_set vertex_set);
let part s w = fst(SV.partition (fun e -> e >= w) s) in
SV.iter (fun s ->
(* Build the subgraph induced by s and following nodes in the ordering *)
Printf.eprintf "selected element %d\n" (G.V.label s);
let subset = SV.add s (part vertex_set s) in
Printf.eprintf "subset %s\n" (print_set subset);
let subgraph = subgraph_ g subset in
if G.nb_edges subgraph > 0 then begin
let scc = G.Components.scc_list subgraph in
(* Find the strongly connected component in the subgraph
* that contains the least node according to the ordering *)
let minnode = SV.min_elt subset in
Printf.eprintf "minnode %d\n" (G.V.label minnode);
let mincomp = List.find (fun l -> List.mem minnode l) scc in
Printf.eprintf "mincomp %s\n" (print_set ((to_set mincomp)));
(* smallest node in the component according to the ordering *)
let startnode = minnode in
let component = subgraph_ subgraph (to_set mincomp) in
G.dot_output component (Printf.sprintf "test-component%d.dot" (G.V.label s));
let subgraph = extract_subgraph g subset in
let scc = G.Components.scc_list subgraph in
(* Find the strongly connected component in the subgraph
* that contains the least node according to the ordering *)
let minnode = SV.min_elt subset in
let mincomp = List.find (fun l -> List.mem minnode l) scc in
(* smallest node in the component according to the ordering *)
let component = extract_subgraph subgraph (to_set mincomp) in
if G.nb_edges component > 0 then begin
G.iter_vertex (fun node ->
Hashtbl.add blocked node false;
Hashtbl.add b node [];
Hashtbl.replace blocked node false;
Hashtbl.replace b node [];
) component;
ignore(circuit startnode startnode component);
end else
Printf.eprintf "No edges to consider\n"
ignore(circuit minnode minnode component);
end
) vertex_set;
!result
List.rev !result
;;
let g = G.Rand.graph ~v:5 ~e:10 () in
G.dot_output g "test.dot";
if Array.length Sys.argv < 3 then begin
Printf.printf "usage: %s num_vertices [v1,v2...]\n" Sys.argv.(0);
exit 1;
end;
let v = int_of_string (Sys.argv.(1)) in
let g = G.create ~size:v () in
let a = Array.init v G.V.create in
for i = 2 to Array.length Sys.argv - 1 do
let v1, v2 = String.split Sys.argv.(i) "," in
G.add_edge g a.(int_of_string v1) a.(int_of_string v2);
done;
let ll = find_all_cycles_johnson g in
List.iter (fun path ->
Printf.printf "path : %s\n"
Printf.printf "%s\n"
(String.join " " (List.map (fun e -> string_of_int (G.V.label e)) path))
) ll

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