http://www.ousob.com --- Legacy Redefined OuSob - File: /wwwroot/clipx/usr/include/boost/graph/edmunds_karp_max_flow.hpp

//======================================================================= // Copyright 2000 University of Notre Dame. // Authors: Jeremy G. Siek, Andrew Lumsdaine, Lie-Quan Lee // // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) //======================================================================= #ifndef EDMUNDS_KARP_MAX_FLOW_HPP #define EDMUNDS_KARP_MAX_FLOW_HPP #include <boost/config.hpp> #include <vector> #include <algorithm> // for std::min and std::max #include <boost/config.hpp> #include <boost/pending/queue.hpp> #include <boost/property_map.hpp> #include <boost/graph/graph_traits.hpp> #include <boost/graph/properties.hpp> #include <boost/graph/filtered_graph.hpp> #include <boost/graph/breadth_first_search.hpp> namespace boost { // The "labeling" algorithm from "Network Flows" by Ahuja, Magnanti, // Orlin. I think this is the same as or very similar to the original // Edmunds-Karp algorithm. This solves the maximum flow problem. namespace detail { template <class Graph, class ResCapMap> filtered_graph<Graph, is_residual_edge<ResCapMap> > residual_graph(Graph& g, ResCapMap residual_capacity) { return filtered_graph<Graph, is_residual_edge<ResCapMap> > (g, is_residual_edge<ResCapMap>(residual_capacity)); } template <class Graph, class PredEdgeMap, class ResCapMap, class RevEdgeMap> inline void augment(Graph& g, typename graph_traits<Graph>::vertex_descriptor src, typename graph_traits<Graph>::vertex_descriptor sink, PredEdgeMap p, ResCapMap residual_capacity, RevEdgeMap reverse_edge) { typename graph_traits<Graph>::edge_descriptor e; typename graph_traits<Graph>::vertex_descriptor u; typedef typename property_traits<ResCapMap>::value_type FlowValue; // find minimum residual capacity along the augmenting path FlowValue delta = (std::numeric_limits<FlowValue>::max)(); e = p[sink]; do { BOOST_USING_STD_MIN(); delta = min BOOST_PREVENT_MACRO_SUBSTITUTION(delta, residual_capacity[e]); u = source(e, g); e = p[u]; } while (u != src); // push delta units of flow along the augmenting path e = p[sink]; do { residual_capacity[e] -= delta; residual_capacity[reverse_edge[e]] += delta; u = source(e, g); e = p[u]; } while (u != src); } } // namespace detail template <class Graph, class CapacityEdgeMap, class ResidualCapacityEdgeMap, class ReverseEdgeMap, class ColorMap, class PredEdgeMap> typename property_traits<CapacityEdgeMap>::value_type edmunds_karp_max_flow (Graph& g, typename graph_traits<Graph>::vertex_descriptor src, typename graph_traits<Graph>::vertex_descriptor sink, CapacityEdgeMap cap, ResidualCapacityEdgeMap res, ReverseEdgeMap rev, ColorMap color, PredEdgeMap pred) { typedef typename graph_traits<Graph>::vertex_descriptor vertex_t; typedef typename property_traits<ColorMap>::value_type ColorValue; typedef color_traits<ColorValue> Color; typename graph_traits<Graph>::vertex_iterator u_iter, u_end; typename graph_traits<Graph>::out_edge_iterator ei, e_end; for (tie(u_iter, u_end) = vertices(g); u_iter != u_end; ++u_iter) for (tie(ei, e_end) = out_edges(*u_iter, g); ei != e_end; ++ei) res[*ei] = cap[*ei]; color[sink] = Color::gray(); while (color[sink] != Color::white()) { boost::queue<vertex_t> Q; breadth_first_search (detail::residual_graph(g, res), src, Q, make_bfs_visitor(record_edge_predecessors(pred, on_tree_edge())), color); if (color[sink] != Color::white()) detail::augment(g, src, sink, pred, res, rev); } // while typename property_traits<CapacityEdgeMap>::value_type flow = 0; for (tie(ei, e_end) = out_edges(src, g); ei != e_end; ++ei) flow += (cap[*ei] - res[*ei]); return flow; } // edmunds_karp_max_flow() namespace detail { //------------------------------------------------------------------------- // Handle default for color property map // use of class here is a VC++ workaround template <class ColorMap> struct edmunds_karp_dispatch2 { template <class Graph, class PredMap, class P, class T, class R> static typename edge_capacity_value<Graph, P, T, R>::type apply (Graph& g, typename graph_traits<Graph>::vertex_descriptor src, typename graph_traits<Graph>::vertex_descriptor sink, PredMap pred, const bgl_named_params<P, T, R>& params, ColorMap color) { return edmunds_karp_max_flow (g, src, sink, choose_const_pmap(get_param(params, edge_capacity), g, edge_capacity), choose_pmap(get_param(params, edge_residual_capacity), g, edge_residual_capacity), choose_const_pmap(get_param(params, edge_reverse), g, edge_reverse), color, pred); } }; template<> struct edmunds_karp_dispatch2<detail::error_property_not_found> { template <class Graph, class PredMap, class P, class T, class R> static typename edge_capacity_value<Graph, P, T, R>::type apply (Graph& g, typename graph_traits<Graph>::vertex_descriptor src, typename graph_traits<Graph>::vertex_descriptor sink, PredMap pred, const bgl_named_params<P, T, R>& params, detail::error_property_not_found) { typedef typename graph_traits<Graph>::edge_descriptor edge_descriptor; typedef typename graph_traits<Graph>::vertices_size_type size_type; size_type n = is_default_param(get_param(params, vertex_color)) ? num_vertices(g) : 1; std::vector<default_color_type> color_vec(n); return edmunds_karp_max_flow (g, src, sink, choose_const_pmap(get_param(params, edge_capacity), g, edge_capacity), choose_pmap(get_param(params, edge_residual_capacity), g, edge_residual_capacity), choose_const_pmap(get_param(params, edge_reverse), g, edge_reverse), make_iterator_property_map(color_vec.begin(), choose_const_pmap (get_param(params, vertex_index), g, vertex_index), color_vec[0]), pred); } }; //------------------------------------------------------------------------- // Handle default for predecessor property map // use of class here is a VC++ workaround template <class PredMap> struct edmunds_karp_dispatch1 { template <class Graph, class P, class T, class R> static typename edge_capacity_value<Graph, P, T, R>::type apply(Graph& g, typename graph_traits<Graph>::vertex_descriptor src, typename graph_traits<Graph>::vertex_descriptor sink, const bgl_named_params<P, T, R>& params, PredMap pred) { typedef typename property_value< bgl_named_params<P,T,R>, vertex_color_t>::type C; return edmunds_karp_dispatch2<C>::apply (g, src, sink, pred, params, get_param(params, vertex_color)); } }; template<> struct edmunds_karp_dispatch1<detail::error_property_not_found> { template <class Graph, class P, class T, class R> static typename edge_capacity_value<Graph, P, T, R>::type apply (Graph& g, typename graph_traits<Graph>::vertex_descriptor src, typename graph_traits<Graph>::vertex_descriptor sink, const bgl_named_params<P, T, R>& params, detail::error_property_not_found) { typedef typename graph_traits<Graph>::edge_descriptor edge_descriptor; typedef typename graph_traits<Graph>::vertices_size_type size_type; size_type n = is_default_param(get_param(params, vertex_predecessor)) ? num_vertices(g) : 1; std::vector<edge_descriptor> pred_vec(n); typedef typename property_value< bgl_named_params<P,T,R>, vertex_color_t>::type C; return edmunds_karp_dispatch2<C>::apply (g, src, sink, make_iterator_property_map(pred_vec.begin(), choose_const_pmap (get_param(params, vertex_index), g, vertex_index), pred_vec[0]), params, get_param(params, vertex_color)); } }; } // namespace detail template <class Graph, class P, class T, class R> typename detail::edge_capacity_value<Graph, P, T, R>::type edmunds_karp_max_flow (Graph& g, typename graph_traits<Graph>::vertex_descriptor src, typename graph_traits<Graph>::vertex_descriptor sink, const bgl_named_params<P, T, R>& params) { typedef typename property_value< bgl_named_params<P,T,R>, vertex_predecessor_t>::type Pred; return detail::edmunds_karp_dispatch1<Pred>::apply (g, src, sink, params, get_param(params, vertex_predecessor)); } template <class Graph> typename property_traits< typename property_map<Graph, edge_capacity_t>::const_type >::value_type edmunds_karp_max_flow (Graph& g, typename graph_traits<Graph>::vertex_descriptor src, typename graph_traits<Graph>::vertex_descriptor sink) { bgl_named_params<int, buffer_param_t> params(0); return edmunds_karp_max_flow(g, src, sink, params); } } // namespace boost #endif // EDMUNDS_KARP_MAX_FLOW_HPP