diff --git a/doc/hawick_circuits.html b/doc/hawick_circuits.html index 92eb5995..100b038b 100644 --- a/doc/hawick_circuits.html +++ b/doc/hawick_circuits.html @@ -13,13 +13,13 @@

hawick_circuits

template <typename Graph, typename Visitor, typename VertexIndexMap>
-void hawick_circuits(Graph const& graph, Visitor visitor, VertexIndexMap const& vim = get(vertex_index, graph));
+void hawick_circuits(Graph const& graph, Visitor visitor, VertexIndexMap const& vim = get(vertex_index, graph), unsigned int const maxLength = 0);
 
 template <typename Graph, typename Visitor, typename VertexIndexMap>
-void hawick_unique_circuits(Graph const& graph, Visitor visitor, VertexIndexMap const& vim = get(vertex_index, graph));
+void hawick_unique_circuits(Graph const& graph, Visitor visitor, VertexIndexMap const& vim = get(vertex_index, graph), unsigned int const maxLength = 0);
-

Enumerate all the elementary circuits in a directed multigraph. Specifically, +

Enumerate all the elementary circuits (of length ≤ maxLength, if nonzero) in a directed multigraph. Specifically, self-loops and redundant circuits caused by parallel edges are enumerated too. hawick_unique_circuits may be used if redundant circuits caused by parallel edges are not desired.

@@ -59,6 +59,12 @@ edges are not desired.

the vertex index map provided by the graph.

+

IN: unsigned int const maxLength = 0

+ +
+

The maximum circuit length to consider. Beyond this it truncates the depth-first search, reducing the computation time by ignoring longer circuits. The default value of maxLength = 0 implies no maximum.

+
+
diff --git a/example/hawick_circuits.cpp b/example/hawick_circuits.cpp index 68265603..71d5a54c 100644 --- a/example/hawick_circuits.cpp +++ b/example/hawick_circuits.cpp @@ -78,7 +78,7 @@ int main(int argc, char const* argv[]) { if (argc < 2) { - std::cout << "usage: " << argv[0] << " num_vertices < input\n"; + std::cout << "usage: " << argv[0] << " \n"; return EXIT_FAILURE; } @@ -88,7 +88,12 @@ int main(int argc, char const* argv[]) build_graph(graph, num_vertices, first_vertex, last_vertex); cycle_printer< std::ostream > visitor(std::cout); - boost::hawick_circuits(graph, visitor); + if (argc == 2) { + boost::hawick_circuits(graph, visitor); + } else { + unsigned int max_length = boost::lexical_cast< unsigned int >(argv[2]); + boost::hawick_circuits(graph, visitor, max_length); + } return EXIT_SUCCESS; } diff --git a/include/boost/graph/hawick_circuits.hpp b/include/boost/graph/hawick_circuits.hpp index ba406549..91cd377f 100644 --- a/include/boost/graph/hawick_circuits.hpp +++ b/include/boost/graph/hawick_circuits.hpp @@ -153,13 +153,14 @@ namespace hawick_circuits_detail public: hawick_circuits_from(Graph const& graph, Visitor& visitor, VertexIndexMap const& vim, Stack& stack, ClosedMatrix& closed, - VerticesSize n_vertices) + VerticesSize n_vertices, unsigned int const maxLength) : graph_(graph) , visitor_(visitor) , vim_(vim) , stack_(stack) , closed_(closed) , blocked_(n_vertices, vim_) + , maxLength_(maxLength) { BOOST_ASSERT(blocked_map_starts_all_unblocked()); @@ -224,6 +225,10 @@ namespace hawick_circuits_detail stack_.push_back(v); block(v); + // Truncate the search if any circuits would exceed maxLength_. + bool const truncate_search = + (maxLength_ > 0 && stack_.size() >= maxLength_); + // Cache some values that are used more than once in the function. VertexIndex const index_of_start = index_of(start); AdjacentVertices const adj_vertices @@ -249,13 +254,19 @@ namespace hawick_circuits_detail found_circuit = true; } + // If required, truncate the search before the subsequent + // recursive call to circuit(). + else if (truncate_search) + continue; + // If `w` is not blocked, we continue searching further down the // same path for a cycle with `w` in it. else if (!is_blocked(w) && circuit(start, w)) found_circuit = true; } - if (found_circuit) + bool const finish_circuit = (found_circuit || truncate_search); + if (finish_circuit) unblock(v); else for (AdjacencyIterator w_it = boost::begin(adj_vertices); @@ -274,7 +285,7 @@ namespace hawick_circuits_detail BOOST_ASSERT(v == stack_.back()); stack_.pop_back(); - return found_circuit; + return finish_circuit; } public: @@ -287,12 +298,14 @@ namespace hawick_circuits_detail Stack& stack_; ClosedMatrix& closed_; BlockedMap blocked_; + unsigned int const maxLength_; }; template < typename GetAdjacentVertices, typename Graph, typename Visitor, typename VertexIndexMap > void call_hawick_circuits(Graph const& graph, - Visitor /* by value */ visitor, VertexIndexMap const& vertex_index_map) + Visitor /* by value */ visitor, VertexIndexMap const& vertex_index_map, + unsigned int const maxLength) { typedef graph_traits< Graph > Traits; typedef typename Traits::vertex_descriptor Vertex; @@ -322,7 +335,8 @@ namespace hawick_circuits_detail // construction. It would be strictly equivalent to have these as // member variables of the sub algorithm. SubAlgorithm sub_algo( - graph, visitor, vertex_index_map, stack, closed, n_vertices); + graph, visitor, vertex_index_map, stack, closed, n_vertices, + maxLength); sub_algo(*start); stack.clear(); typename ClosedMatrix::iterator row, last_row = closed.end(); @@ -333,30 +347,35 @@ namespace hawick_circuits_detail template < typename GetAdjacentVertices, typename Graph, typename Visitor > void call_hawick_circuits( - Graph const& graph, BOOST_FWD_REF(Visitor) visitor) + Graph const& graph, BOOST_FWD_REF(Visitor) visitor, + unsigned int const maxLength) { call_hawick_circuits< GetAdjacentVertices >(graph, - boost::forward< Visitor >(visitor), get(vertex_index, graph)); + boost::forward< Visitor >(visitor), get(vertex_index, graph), + maxLength); } } // end namespace hawick_circuits_detail //! Enumerate all the elementary circuits in a directed multigraph. template < typename Graph, typename Visitor, typename VertexIndexMap > void hawick_circuits(BOOST_FWD_REF(Graph) graph, BOOST_FWD_REF(Visitor) visitor, - BOOST_FWD_REF(VertexIndexMap) vertex_index_map) + BOOST_FWD_REF(VertexIndexMap) vertex_index_map, + unsigned int const maxLength = 0) { hawick_circuits_detail::call_hawick_circuits< hawick_circuits_detail::get_all_adjacent_vertices >( boost::forward< Graph >(graph), boost::forward< Visitor >(visitor), - boost::forward< VertexIndexMap >(vertex_index_map)); + boost::forward< VertexIndexMap >(vertex_index_map), maxLength); } template < typename Graph, typename Visitor > -void hawick_circuits(BOOST_FWD_REF(Graph) graph, BOOST_FWD_REF(Visitor) visitor) +void hawick_circuits(BOOST_FWD_REF(Graph) graph, BOOST_FWD_REF(Visitor) visitor, + unsigned int const maxLength = 0) { hawick_circuits_detail::call_hawick_circuits< hawick_circuits_detail::get_all_adjacent_vertices >( - boost::forward< Graph >(graph), boost::forward< Visitor >(visitor)); + boost::forward< Graph >(graph), boost::forward< Visitor >(visitor), + maxLength); } /*! @@ -366,21 +385,24 @@ void hawick_circuits(BOOST_FWD_REF(Graph) graph, BOOST_FWD_REF(Visitor) visitor) template < typename Graph, typename Visitor, typename VertexIndexMap > void hawick_unique_circuits(BOOST_FWD_REF(Graph) graph, BOOST_FWD_REF(Visitor) visitor, - BOOST_FWD_REF(VertexIndexMap) vertex_index_map) + BOOST_FWD_REF(VertexIndexMap) vertex_index_map, + unsigned int const maxLength = 0) { hawick_circuits_detail::call_hawick_circuits< hawick_circuits_detail::get_unique_adjacent_vertices >( boost::forward< Graph >(graph), boost::forward< Visitor >(visitor), - boost::forward< VertexIndexMap >(vertex_index_map)); + boost::forward< VertexIndexMap >(vertex_index_map), maxLength); } template < typename Graph, typename Visitor > void hawick_unique_circuits( - BOOST_FWD_REF(Graph) graph, BOOST_FWD_REF(Visitor) visitor) + BOOST_FWD_REF(Graph) graph, BOOST_FWD_REF(Visitor) visitor, + unsigned int const maxLength = 0) { hawick_circuits_detail::call_hawick_circuits< hawick_circuits_detail::get_unique_adjacent_vertices >( - boost::forward< Graph >(graph), boost::forward< Visitor >(visitor)); + boost::forward< Graph >(graph), boost::forward< Visitor >(visitor), + maxLength); } } // end namespace boost