71 lines
2.1 KiB
C++
71 lines
2.1 KiB
C++
//=======================================================================
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// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
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// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
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//
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// Distributed under the Boost Software License, Version 1.0. (See
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// accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//=======================================================================
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#include <boost/config.hpp>
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#include <iostream>
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#include <list>
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#include <algorithm>
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#include <boost/graph/adjacency_list.hpp>
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#include <boost/graph/topological_sort.hpp>
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#include <iterator>
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#include <utility>
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typedef std::pair< std::size_t, std::size_t > Pair;
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/*
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Topological sort example
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The topological sort algorithm creates a linear ordering
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of the vertices such that if edge (u,v) appears in the graph,
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then u comes before v in the ordering.
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Sample output:
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A topological ordering: 2 5 0 1 4 3
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*/
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int main(int, char*[])
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{
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// begin
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using namespace boost;
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/* Topological sort will need to color the graph. Here we use an
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internal decorator, so we "property" the color to the graph.
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*/
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typedef adjacency_list< vecS, vecS, directedS,
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property< vertex_color_t, default_color_type > >
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Graph;
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typedef boost::graph_traits< Graph >::vertex_descriptor Vertex;
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Pair edges[6] = { Pair(0, 1), Pair(2, 4), Pair(2, 5), Pair(0, 3),
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Pair(1, 4), Pair(4, 3) };
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#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
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// VC++ can't handle the iterator constructor
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Graph G(6);
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for (std::size_t j = 0; j < 6; ++j)
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add_edge(edges[j].first, edges[j].second, G);
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#else
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Graph G(edges, edges + 6, 6);
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#endif
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boost::property_map< Graph, vertex_index_t >::type id
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= get(vertex_index, G);
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typedef std::vector< Vertex > container;
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container c;
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topological_sort(G, std::back_inserter(c));
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std::cout << "A topological ordering: ";
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for (container::reverse_iterator ii = c.rbegin(); ii != c.rend(); ++ii)
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std::cout << id[*ii] << " ";
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std::cout << std::endl;
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return 0;
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}
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