Question

I have a boost graph defined as

typedef boost::adjacency_list<boost::setS, boost::listS,
        boost::undirectedS, CoordNode, CoordSegment> BGraph;
typedef boost::graph_traits<BGraph>::vertex_descriptor  VertexDesc;
BGraph _graph;

and I want to know the connected components of same graph with

 int num = boost::connected_components(_graph, propMap);

I already tried to create the required writable property map (propMap) with

typedef  std::map<VertexDesc, size_t> IndexMap;
IndexMap mapIndex;
boost::associative_property_map<IndexMap> propMap(mapIndex);
VertexIterator di, dj;
boost::tie(di, dj) = boost::vertices(_graph);
for(di; di != dj; ++di){
    boost::put(propMap, (*di), 0);
}

but that doesn't work; I get compilations errors.

If the vertex container would be vecS, it would be easier, because a simple array or vector would suffice. But what am I supposed to pass to this function if I have listS as the vertex container?

How can I create the necessary writable property map? Can somebody give me an example?

Was it helpful?

Solution

Works!

typedef boost::adjacency_list
    <boost::setS, boost::listS,
        boost::undirectedS, 
        boost::no_property,
        boost::no_property> Graph;
    typedef boost::graph_traits<Graph>::vertex_iterator VertexIterator;
    typedef boost::graph_traits<Graph>::vertex_descriptor   VertexDesc;
    typedef std::map<VertexDesc, size_t> VertexDescMap; 

Graph graph;

...


VertexDescMap idxMap;
boost::associative_property_map<VertexDescMap> indexMap(idxMap);
VertexIterator di, dj;
boost::tie(di, dj) = boost::vertices(_graph);
for(int i = 0; di != dj; ++di,++i){
    boost::put(indexMap, (*di), i);
}


std::map<VertexDesc, size_t> compMap;
boost::associative_property_map<VertexDescMap> componentMap(compMap);            
boost::associative_property_map<VertexDescMap>& componentMap;

boost::connected_components(_graph, componentMap, boost::vertex_index_map(indexMap));   
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