--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/epoc32/include/stdapis/boost/graph/edge_connectivity.hpp Tue Mar 16 16:12:26 2010 +0000
@@ -0,0 +1,181 @@
+//=======================================================================
+// 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 BOOST_EDGE_CONNECTIVITY
+#define BOOST_EDGE_CONNECTIVITY
+
+// WARNING: not-yet fully tested!
+
+#include <boost/config.hpp>
+#include <vector>
+#include <set>
+#include <algorithm>
+#include <boost/graph/edmunds_karp_max_flow.hpp>
+
+namespace boost {
+
+ namespace detail {
+
+ template <class Graph>
+ inline
+ std::pair<typename graph_traits<Graph>::vertex_descriptor,
+ typename graph_traits<Graph>::degree_size_type>
+ min_degree_vertex(Graph& g)
+ {
+ typedef graph_traits<Graph> Traits;
+ typename Traits::vertex_descriptor p;
+ typedef typename Traits::degree_size_type size_type;
+ size_type delta = (std::numeric_limits<size_type>::max)();
+
+ typename Traits::vertex_iterator i, iend;
+ for (tie(i, iend) = vertices(g); i != iend; ++i)
+ if (degree(*i, g) < delta) {
+ delta = degree(*i, g);
+ p = *i;
+ }
+ return std::make_pair(p, delta);
+ }
+
+ template <class Graph, class OutputIterator>
+ void neighbors(const Graph& g,
+ typename graph_traits<Graph>::vertex_descriptor u,
+ OutputIterator result)
+ {
+ typename graph_traits<Graph>::adjacency_iterator ai, aend;
+ for (tie(ai, aend) = adjacent_vertices(u, g); ai != aend; ++ai)
+ *result++ = *ai;
+ }
+
+ template <class Graph, class VertexIterator, class OutputIterator>
+ void neighbors(const Graph& g,
+ VertexIterator first, VertexIterator last,
+ OutputIterator result)
+ {
+ for (; first != last; ++first)
+ neighbors(g, *first, result);
+ }
+
+ } // namespace detail
+
+ // O(m n)
+ template <class VertexListGraph, class OutputIterator>
+ typename graph_traits<VertexListGraph>::degree_size_type
+ edge_connectivity(VertexListGraph& g, OutputIterator disconnecting_set)
+ {
+ //-------------------------------------------------------------------------
+ // Type Definitions
+ typedef graph_traits<VertexListGraph> Traits;
+ typedef typename Traits::vertex_iterator vertex_iterator;
+ typedef typename Traits::edge_iterator edge_iterator;
+ typedef typename Traits::out_edge_iterator out_edge_iterator;
+ typedef typename Traits::vertex_descriptor vertex_descriptor;
+ typedef typename Traits::degree_size_type degree_size_type;
+ typedef color_traits<default_color_type> Color;
+
+ typedef adjacency_list_traits<vecS, vecS, directedS> Tr;
+ typedef typename Tr::edge_descriptor Tr_edge_desc;
+ typedef adjacency_list<vecS, vecS, directedS, no_property,
+ property<edge_capacity_t, degree_size_type,
+ property<edge_residual_capacity_t, degree_size_type,
+ property<edge_reverse_t, Tr_edge_desc> > > >
+ FlowGraph;
+ typedef typename graph_traits<FlowGraph>::edge_descriptor edge_descriptor;
+
+ //-------------------------------------------------------------------------
+ // Variable Declarations
+ vertex_descriptor u, v, p, k;
+ edge_descriptor e1, e2;
+ bool inserted;
+ vertex_iterator vi, vi_end;
+ edge_iterator ei, ei_end;
+ degree_size_type delta, alpha_star, alpha_S_k;
+ std::set<vertex_descriptor> S, neighbor_S;
+ std::vector<vertex_descriptor> S_star, non_neighbor_S;
+ std::vector<default_color_type> color(num_vertices(g));
+ std::vector<edge_descriptor> pred(num_vertices(g));
+
+ //-------------------------------------------------------------------------
+ // Create a network flow graph out of the undirected graph
+ FlowGraph flow_g(num_vertices(g));
+
+ typename property_map<FlowGraph, edge_capacity_t>::type
+ cap = get(edge_capacity, flow_g);
+ typename property_map<FlowGraph, edge_residual_capacity_t>::type
+ res_cap = get(edge_residual_capacity, flow_g);
+ typename property_map<FlowGraph, edge_reverse_t>::type
+ rev_edge = get(edge_reverse, flow_g);
+
+ for (tie(ei, ei_end) = edges(g); ei != ei_end; ++ei) {
+ u = source(*ei, g), v = target(*ei, g);
+ tie(e1, inserted) = add_edge(u, v, flow_g);
+ cap[e1] = 1;
+ tie(e2, inserted) = add_edge(v, u, flow_g);
+ cap[e2] = 1; // not sure about this
+ rev_edge[e1] = e2;
+ rev_edge[e2] = e1;
+ }
+
+ //-------------------------------------------------------------------------
+ // The Algorithm
+
+ tie(p, delta) = detail::min_degree_vertex(g);
+ S_star.push_back(p);
+ alpha_star = delta;
+ S.insert(p);
+ neighbor_S.insert(p);
+ detail::neighbors(g, S.begin(), S.end(),
+ std::inserter(neighbor_S, neighbor_S.begin()));
+
+ std::set_difference(vertices(g).first, vertices(g).second,
+ neighbor_S.begin(), neighbor_S.end(),
+ std::back_inserter(non_neighbor_S));
+
+ while (!non_neighbor_S.empty()) { // at most n - 1 times
+ k = non_neighbor_S.front();
+
+ alpha_S_k = edmunds_karp_max_flow
+ (flow_g, p, k, cap, res_cap, rev_edge, &color[0], &pred[0]);
+
+ if (alpha_S_k < alpha_star) {
+ alpha_star = alpha_S_k;
+ S_star.clear();
+ for (tie(vi, vi_end) = vertices(flow_g); vi != vi_end; ++vi)
+ if (color[*vi] != Color::white())
+ S_star.push_back(*vi);
+ }
+ S.insert(k);
+ neighbor_S.insert(k);
+ detail::neighbors(g, k, std::inserter(neighbor_S, neighbor_S.begin()));
+ non_neighbor_S.clear();
+ std::set_difference(vertices(g).first, vertices(g).second,
+ neighbor_S.begin(), neighbor_S.end(),
+ std::back_inserter(non_neighbor_S));
+ }
+ //-------------------------------------------------------------------------
+ // Compute edges of the cut [S*, ~S*]
+ std::vector<bool> in_S_star(num_vertices(g), false);
+ typename std::vector<vertex_descriptor>::iterator si;
+ for (si = S_star.begin(); si != S_star.end(); ++si)
+ in_S_star[*si] = true;
+
+ degree_size_type c = 0;
+ for (si = S_star.begin(); si != S_star.end(); ++si) {
+ out_edge_iterator ei, ei_end;
+ for (tie(ei, ei_end) = out_edges(*si, g); ei != ei_end; ++ei)
+ if (!in_S_star[target(*ei, g)]) {
+ *disconnecting_set++ = *ei;
+ ++c;
+ }
+ }
+ return c;
+ }
+
+} // namespace boost
+
+#endif // BOOST_EDGE_CONNECTIVITY