graph/example/topo_sort.cpp
Jeremy Siek 048cf582e2 *** empty log message ***
[SVN r11549]
2001-11-03 06:40:35 +00:00

91 lines
2.8 KiB
C++

//=======================================================================
// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
//
// This file is part of the Boost Graph Library
//
// You should have received a copy of the License Agreement for the
// Boost Graph Library along with the software; see the file LICENSE.
// If not, contact Office of Research, University of Notre Dame, Notre
// Dame, IN 46556.
//
// Permission to modify the code and to distribute modified code is
// granted, provided the text of this NOTICE is retained, a notice that
// the code was modified is included with the above COPYRIGHT NOTICE and
// with the COPYRIGHT NOTICE in the LICENSE file, and that the LICENSE
// file is distributed with the modified code.
//
// LICENSOR MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED.
// By way of example, but not limitation, Licensor MAKES NO
// REPRESENTATIONS OR WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY
// PARTICULAR PURPOSE OR THAT THE USE OF THE LICENSED SOFTWARE COMPONENTS
// OR DOCUMENTATION WILL NOT INFRINGE ANY PATENTS, COPYRIGHTS, TRADEMARKS
// OR OTHER RIGHTS.
//=======================================================================
#include <boost/config.hpp>
#include <iostream>
#include <list>
#include <algorithm>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/topological_sort.hpp>
#include <iterator>
#include <utility>
typedef std::pair<std::size_t,std::size_t> Pair;
/*
Topological sort example
The topological sort algorithm creates a linear ordering
of the vertices such that if edge (u,v) appears in the graph,
then u comes before v in the ordering.
Sample output:
A topological ordering: 2 5 0 1 4 3
*/
int
main(int , char* [])
{
//begin
using namespace boost;
/* Topological sort will need to color the graph. Here we use an
internal decorator, so we "property" the color to the graph.
*/
typedef adjacency_list<vecS, vecS, directedS,
property<vertex_color_t, default_color_type> > Graph;
typedef boost::graph_traits<Graph>::vertex_descriptor Vertex;
Pair edges[7] = { Pair(0,1), Pair(2,4),
Pair(2,5),
Pair(0,3), Pair(1,4),
Pair(4,3), Pair(5,5) };
#ifdef BOOST_MSVC
// VC++ can't handle the iterator constructor
Graph G(6);
for (std::size_t j = 0; j < 7; ++j)
add_edge(edges[j].first, edges[j].second, G);
#else
Graph G(edges, edges + 7, 6);
#endif
boost::property_map<Graph, vertex_index_t>::type id = get(vertex_index, G);
typedef std::vector< Vertex > container;
container c;
topological_sort(G, std::back_inserter(c));
std::cout << "A topological ordering: ";
for (container::reverse_iterator ii = c.rbegin();
ii != c.rend(); ++ii)
std::cout << id[*ii] << " ";
std::cout << std::endl;
return 0;
}