| //======================================================================= |
| // Copyright 2001 University of Notre Dame. |
| // Author: Jeremy G. Siek |
| // |
| // 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) |
| //======================================================================= |
| |
| /* |
| Sample output: |
| |
| filtered edge set: (A,B) (C,D) (D,B) |
| filtered out-edges: |
| A --> B |
| B --> |
| C --> D |
| D --> B |
| E --> |
| */ |
| |
| #include <boost/config.hpp> |
| #include <iostream> |
| #include <boost/graph/adjacency_list.hpp> |
| #include <boost/graph/filtered_graph.hpp> |
| #include <boost/graph/graph_utility.hpp> |
| |
| template <typename EdgeWeightMap> |
| struct positive_edge_weight { |
| positive_edge_weight() { } |
| positive_edge_weight(EdgeWeightMap weight) : m_weight(weight) { } |
| template <typename Edge> |
| bool operator()(const Edge& e) const { |
| return 0 < boost::get(m_weight, e); |
| } |
| EdgeWeightMap m_weight; |
| }; |
| |
| |
| int main() |
| { |
| using namespace boost; |
| |
| typedef adjacency_list<multisetS, vecS, directedS, |
| no_property, property<edge_weight_t, int> > Graph; |
| typedef property_map<Graph, edge_weight_t>::type EdgeWeightMap; |
| |
| enum { A, B, C, D, E, N }; |
| const char* name = "ABCDE"; |
| Graph g(N); |
| add_edge(A, B, 2, g); |
| add_edge(A, C, 0, g); |
| add_edge(C, D, 1, g); |
| add_edge(C, D, 0, g); |
| add_edge(C, D, 3, g); |
| add_edge(C, E, 0, g); |
| add_edge(D, B, 3, g); |
| add_edge(E, C, 0, g); |
| |
| EdgeWeightMap weight = get(edge_weight, g); |
| |
| std::cout << "unfiltered edge_range(C,D)\n"; |
| graph_traits<Graph>::out_edge_iterator f, l; |
| for (boost::tie(f, l) = edge_range(C, D, g); f != l; ++f) |
| std::cout << name[source(*f, g)] << " --" << weight[*f] |
| << "-> " << name[target(*f, g)] << "\n"; |
| |
| positive_edge_weight<EdgeWeightMap> filter(weight); |
| typedef filtered_graph<Graph, positive_edge_weight<EdgeWeightMap> > FGraph; |
| FGraph fg(g, filter); |
| |
| std::cout << "filtered edge_range(C,D)\n"; |
| graph_traits<FGraph>::out_edge_iterator first, last; |
| for (boost::tie(first, last) = edge_range(C, D, fg); first != last; ++first) |
| std::cout << name[source(*first, fg)] << " --" << weight[*first] |
| << "-> " << name[target(*first, fg)] << "\n"; |
| |
| return 0; |
| } |