Commit 0c4cab37 by Tiago Peixoto

### Include stoer_wagner_min_cut boost header to keep compatibility with older boost versions

parent 3a7b665f
 // Copyright Daniel Trebbien 2010. // Distributed under the Boost Software License, Version 1.0. // (See accompanying file LICENSE_1_0.txt or the copy at // http://www.boost.org/LICENSE_1_0.txt) #ifndef BOOST_GRAPH_STOER_WAGNER_MIN_CUT_HPP #define BOOST_GRAPH_STOER_WAGNER_MIN_CUT_HPP 1 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include namespace boost { namespace detail { /** * \brief Performs a phase of the Stoer-Wagner min-cut algorithm * * Performs a phase of the Stoer-Wagner min-cut algorithm. * * As described by Stoer & Wagner (1997), a phase is simply a maximum adjacency search * (also called a maximum cardinality search), which results in the selection of two vertices * \em s and \em t, and, as a side product, a minimum s-t cut of * the input graph. Here, the input graph is basically \p g, but some vertices are virtually * assigned to others as a way of viewing \p g as a graph with some sets of * vertices merged together. * * This implementation is a translation of pseudocode by Professor Uri Zwick, * School of Computer Science, Tel Aviv University. * * \pre \p g is a connected, undirected graph * \param[in] g the input graph * \param[in] assignments a read/write property map from each vertex to the vertex that it is assigned to * \param[in] assignedVertices a list of vertices that are assigned to others * \param[in] weights a readable property map from each edge to its weight (a non-negative value) * \param[out] pq a keyed, updatable max-priority queue * \returns a tuple (\em s, \em t, \em w) of the "s" and "t" * of the minimum s-t cut and the cut weight \em w * of the minimum s-t cut. * \see http://www.cs.tau.ac.il/~zwick/grad-algo-08/gmc.pdf * * \author Daniel Trebbien * \date 2010-09-11 */ template boost::tuple::vertex_descriptor, typename boost::graph_traits::vertex_descriptor, typename boost::property_traits::value_type> stoer_wagner_phase(const UndirectedGraph& g, VertexAssignmentMap assignments, const std::set::vertex_descriptor>& assignedVertices, WeightMap weights, KeyedUpdatablePriorityQueue& pq) { typedef typename boost::graph_traits::vertex_descriptor vertex_descriptor; typedef typename boost::property_traits::value_type weight_type; BOOST_ASSERT(pq.empty()); typename KeyedUpdatablePriorityQueue::key_map keys = pq.keys(); BGL_FORALL_VERTICES_T(v, g, UndirectedGraph) { if (v == get(assignments, v)) { // foreach u \in V do put(keys, v, weight_type(0)); pq.push(v); } } BOOST_ASSERT(pq.size() >= 2); vertex_descriptor s = boost::graph_traits::null_vertex(); vertex_descriptor t = boost::graph_traits::null_vertex(); weight_type w; while (!pq.empty()) { // while PQ \neq {} do const vertex_descriptor u = pq.top(); // u = extractmax(PQ) w = get(keys, u); pq.pop(); s = t; t = u; BGL_FORALL_OUTEDGES_T(u, e, g, UndirectedGraph) { // foreach (u, v) \in E do const vertex_descriptor v = get(assignments, target(e, g)); if (pq.contains(v)) { // if v \in PQ then put(keys, v, get(keys, v) + get(weights, e)); // increasekey(PQ, v, wA(v) + w(u, v)) pq.update(v); } } typename std::set::const_iterator assignedVertexIt, assignedVertexEnd = assignedVertices.end(); for (assignedVertexIt = assignedVertices.begin(); assignedVertexIt != assignedVertexEnd; ++assignedVertexIt) { const vertex_descriptor uPrime = *assignedVertexIt; if (get(assignments, uPrime) == u) { BGL_FORALL_OUTEDGES_T(uPrime, e, g, UndirectedGraph) { // foreach (u, v) \in E do const vertex_descriptor v = get(assignments, target(e, g)); if (pq.contains(v)) { // if v \in PQ then put(keys, v, get(keys, v) + get(weights, e)); // increasekey(PQ, v, wA(v) + w(u, v)) pq.update(v); } } } } } return boost::make_tuple(s, t, w); } /** * \brief Computes a min-cut of the input graph * * Computes a min-cut of the input graph using the Stoer-Wagner algorithm. * * \pre \p g is a connected, undirected graph * \pre pq.empty() * \param[in] g the input graph * \param[in] weights a readable property map from each edge to its weight (a non-negative value) * \param[out] parities a writable property map from each vertex to a bool type object for * distinguishing the two vertex sets of the min-cut * \param[out] assignments a read/write property map from each vertex to a \c vertex_descriptor object. This * map serves as work space, and no particular meaning should be derived from property values * after completion of the algorithm. * \param[out] pq a keyed, updatable max-priority queue * \returns the cut weight of the min-cut * \see http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.114.6687&rep=rep1&type=pdf * \see http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.31.614&rep=rep1&type=pdf * * \author Daniel Trebbien * \date 2010-09-11 */ template typename boost::property_traits::value_type stoer_wagner_min_cut(const UndirectedGraph& g, WeightMap weights, ParityMap parities, VertexAssignmentMap assignments, KeyedUpdatablePriorityQueue& pq) { BOOST_CONCEPT_ASSERT((boost::IncidenceGraphConcept)); BOOST_CONCEPT_ASSERT((boost::VertexListGraphConcept)); typedef typename boost::graph_traits::vertex_descriptor vertex_descriptor; typedef typename boost::graph_traits::vertices_size_type vertices_size_type; typedef typename boost::graph_traits::edge_descriptor edge_descriptor; BOOST_CONCEPT_ASSERT((boost::Convertible::directed_category, boost::undirected_tag>)); BOOST_CONCEPT_ASSERT((boost::ReadablePropertyMapConcept)); typedef typename boost::property_traits::value_type weight_type; BOOST_CONCEPT_ASSERT((boost::WritablePropertyMapConcept)); typedef typename boost::property_traits::value_type parity_type; BOOST_CONCEPT_ASSERT((boost::ReadWritePropertyMapConcept)); BOOST_CONCEPT_ASSERT((boost::Convertible::value_type>)); BOOST_CONCEPT_ASSERT((boost::KeyedUpdatableQueueConcept)); vertices_size_type n = num_vertices(g); if (n < 2) throw boost::bad_graph("the input graph must have at least two vertices."); else if (!pq.empty()) throw std::invalid_argument("the max-priority queue must be empty initially."); std::set assignedVertices; // initialize assignments (all vertices are initially assigned to themselves) BGL_FORALL_VERTICES_T(v, g, UndirectedGraph) { put(assignments, v, v); } vertex_descriptor s, t; weight_type bestW; boost::tie(s, t, bestW) = boost::detail::stoer_wagner_phase(g, assignments, assignedVertices, weights, pq); BOOST_ASSERT(s != t); BGL_FORALL_VERTICES_T(v, g, UndirectedGraph) { put(parities, v, parity_type(v == t ? 1 : 0)); } put(assignments, t, s); assignedVertices.insert(t); --n; for (; n >= 2; --n) { weight_type w; boost::tie(s, t, w) = boost::detail::stoer_wagner_phase(g, assignments, assignedVertices, weights, pq); BOOST_ASSERT(s != t); if (w < bestW) { BGL_FORALL_VERTICES_T(v, g, UndirectedGraph) { put(parities, v, parity_type(get(assignments, v) == t ? 1 : 0)); if (get(assignments, v) == t) // all vertices that were assigned to t are now assigned to s put(assignments, v, s); } bestW = w; } else { BGL_FORALL_VERTICES_T(v, g, UndirectedGraph) { if (get(assignments, v) == t) // all vertices that were assigned to t are now assigned to s put(assignments, v, s); } } put(assignments, t, s); assignedVertices.insert(t); } BOOST_ASSERT(pq.empty()); return bestW; } } // end namespace detail within namespace boost template inline typename boost::property_traits::value_type stoer_wagner_min_cut(const UndirectedGraph& g, WeightMap weights, const boost::bgl_named_params& params) { typedef typename boost::graph_traits::vertex_descriptor vertex_descriptor; typedef typename std::vector::size_type heap_container_size_type; typedef typename boost::property_traits::value_type weight_type; typedef boost::bgl_named_params params_type; BOOST_GRAPH_DECLARE_CONVERTED_PARAMETERS(params_type, params) BOOST_AUTO(pq, (boost::detail::make_priority_queue_from_arg_pack_gen >(choose_param(get_param(params, boost::distance_zero_t()), weight_type(0)))(g, arg_pack))); return boost::detail::stoer_wagner_min_cut(g, weights, choose_param(get_param(params, boost::parity_map_t()), boost::dummy_property_map()), boost::detail::make_property_map_from_arg_pack_gen(vertex_descriptor())(g, arg_pack), pq ); } template inline typename boost::property_traits::value_type stoer_wagner_min_cut(const UndirectedGraph& g, WeightMap weights) { return boost::stoer_wagner_min_cut(g, weights, boost::vertex_index_map(get(boost::vertex_index, g))); } } // end namespace boost #include #endif // !BOOST_GRAPH_STOER_WAGNER_MIN_CUT_HPP
 ... ... @@ -67,7 +67,8 @@ libgraph_tool_core_la_workaround_HEADERS = \ ../boost-workaround/boost/graph/overloading.hpp \ ../boost-workaround/boost/graph/push_relabel_max_flow.hpp \ ../boost-workaround/boost/graph/copy_alt.hpp \ ../boost-workaround/boost/graph/reverse_graph_alt.hpp ../boost-workaround/boost/graph/reverse_graph_alt.hpp \ ../boost-workaround/boost/graph/stoer_wagner_min_cut.hpp libgraph_tool_core_la_LIBADD = $(MOD_LIBADD) libgraph_tool_core_la_LDFLAGS =$(MOD_LDFLAGS) ... ...
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