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[英]How can I solve this error in Printing Nodes and Edges Boost Graph Library?
[英]How do I attach objects to the nodes and edges of a graph using the Boost Graph Library?
我想通過將正確封裝的類附加到圖形節點和邊上來更有效地使用Boost Graph Library。 我對附加int或POD結構不感興趣。 根據其他StackOverFlow文章的建議,我開發了以下示例應用程序。 有人能告訴我我需要撒在EdgeInfo類上的魔力才能使它編譯嗎?
我將Visual Studio 2010與Boost 1.54.0一起使用。
//------------------------------------------------------------------------
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/properties.hpp>
#include <boost/graph/dijkstra_shortest_paths.hpp>
#include <iostream>
//------------------------------------------------------------------------
struct VertexInfo
{
struct Tag
{
typedef boost::vertex_property_tag kind;
static std::size_t const num; // ???
};
typedef boost::property<Tag, VertexInfo> Property;
};
std::size_t const VertexInfo::Tag::num = reinterpret_cast<std::size_t> (&VertexInfo::Tag::num);
//------------------------------------------------------------------------
class EdgeInfo
{
int _nWeight;
public:
int getWeight () const {return _nWeight;}
struct Tag
{
typedef boost::edge_property_tag kind;
static std::size_t const num; // ???
};
typedef boost::property<boost::edge_weight_t, int> Weight;
typedef boost::property<Tag, EdgeInfo> Property;
EdgeInfo (int nWeight = 9999) : _nWeight (nWeight) {}
};
std::size_t const EdgeInfo::Tag::num = reinterpret_cast<std::size_t> (&EdgeInfo::Tag::num);
//------------------------------------------------------------------------
typedef boost::property<boost::edge_weight_t, int> EdgeProperty;
typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, VertexInfo::Property, EdgeProperty> GraphWorking;
typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, VertexInfo::Property, EdgeInfo::Property> GraphBroken;
//------------------------------------------------------------------------
template<typename GraphType, typename EdgeType> void
dijkstra (GraphType g, EdgeType e)
{
typedef boost::graph_traits<GraphType>::vertex_descriptor VertexDesc;
typedef boost::graph_traits<GraphType>::edge_descriptor EdgeDesc;
VertexDesc u = add_vertex (g);
VertexDesc v = add_vertex (g);
std::pair<EdgeDesc, bool> result = add_edge (u, v, e, g);
std::vector<VertexDesc> vecParent (num_vertices (g), 0);
dijkstra_shortest_paths (g, u, boost::predecessor_map (&vecParent[0]));
}
//------------------------------------------------------------------------
int
main (int argc, char** argv)
{
#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
std::cout << "Buy a new compiler\n";
#else
std::cout << "Your compiler is fine\n";
#endif
GraphWorking gWorking;
GraphBroken gBroken;
dijkstra (gWorking, 3);
dijkstra (gBroken, EdgeInfo (4));
}
//------------------------------------------------------------------------
當我運行您的代碼時,由於dijkstra中的距離圖導致了numeric_limits錯誤。
“錯誤1錯誤C2440:”:無法從'int'轉換為'D'c:\\ Program Files(x86)\\ Microsoft Visual Studio 10.0 \\ VC \\ include \\ limits 92“可能來自http:// www的這一部分.boost.org / DOC /庫/ 1_55_0 /升壓/圖形/ dijkstra_shortest_paths.hpp
typedef typename property_traits<DistanceMap>::value_type D;
D inf = choose_param(get_param(params, distance_inf_t()),
(std::numeric_limits<D>::max)());
我認為,為節點和邊緣綁定真實類可能是一種更簡單的方法。 創建值得提供大多數提升算法所需的所有必需的標記屬性(索引,權重,顏色等)的頂點和邊屬性類,比其價值更大。
不要忘記Edge類!= Edge屬性。
邊緣類實際上是graph_traits :: edge_discriptor。
屬性是與每個邊關聯的數據。 頂點相同。
我將使用捆綁的屬性,並在每個屬性中添加一個指向您的類的指針。
這是一個例子
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/properties.hpp>
#include <boost/graph/dijkstra_shortest_paths.hpp>
#include <boost/property_map/property_map.hpp>
#include <iostream>
//Fancy Edge class
class EdgeData
{
int _data;
public:
EdgeData(){
_data=0;
}
EdgeData(int data){
_data= data;
}
void printHello(){
std::cout << "hello " << _data << std::endl;
}
};
//Fancy Vert class
class VertexData
{
int _data;
public:
VertexData(){
_data=0;
}
VertexData(int data){
_data= data;
}
void printHello(){
std::cout << "hello " << _data << std::endl;
}
};
//bundled properties
struct VertexProps
{
VertexData* data;
};
struct EdgeProps
{
size_t weight;
EdgeData* data;
};
//Graph
typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS,
VertexProps,EdgeProps> Graph;
//helpers
//Vertex
typedef boost::graph_traits<Graph>::vertex_descriptor Vertex;
//Edge
typedef boost::graph_traits<Graph>::edge_descriptor Edge;
//------------------------------------------------------------------------
template<typename GraphType> void
templateFunction (GraphType g)
{
typedef boost::graph_traits<GraphType>::edge_iterator edge_iter;
std::pair<edge_iter, edge_iter> ep;
edge_iter ei, ei_end;
ep = edges(g);
ei_end = ep.second;
for (ei = ep.first; ei != ei_end; ++ei){
g[*ei].data->printHello();
}
}
//if you want to alter the graph use referenced &graph
template<typename GraphType,typename EdgePropType> void
templateFuctionProps(GraphType &g, EdgePropType e)
{
typedef boost::graph_traits<GraphType>::vertex_descriptor VertexDesc;
VertexDesc v = add_vertex(g);
VertexDesc u = add_vertex(g);
//add an edge with the Edge property
add_edge(v,u,e,g);
}
//------------------------------------------------------------------------
int
main (int argc, char** argv)
{
Graph g;
//vertex holder
std::vector<Vertex> verts;
//add some verts
for(size_t i = 0; i < 5; ++i){
Vertex v = add_vertex(g);
g[v].data = new VertexData(i%2);
verts.push_back(v);
}
//add some edges
for(size_t i = 0; i < 4; ++i){
std::pair<Edge,bool> p = add_edge(verts.at(i),verts.at(i+1),g);
Edge e = p.first;
g[e].data = new EdgeData(i%3);
g[e].weight = 5;
}
//iterate edges and call a class function
typedef boost::graph_traits<Graph>::edge_iterator edge_iter;
std::pair<edge_iter, edge_iter> ep;
edge_iter ei, ei_end;
ep = edges(g);
ei_end = ep.second;
for (ei = ep.first; ei != ei_end; ++ei){
g[*ei].data->printHello();
}
std::cout << "Iterate with template with template " << std::endl;
templateFunction(g);
//Use an edge property in a function
EdgeProps edgeProp;
edgeProp.weight = 5;
edgeProp.data = new EdgeData(150);
std::cout << "Modity graph with template function " << std::endl;
templateFuctionProps(g,edgeProp);
std::cout << "Iterate again with template" << std::endl;
templateFunction(g);
//getting the weight property
boost::property_map<Graph,size_t EdgeProps::*>::type w
= get(&EdgeProps::weight, g);
std::cout << "Print weights" << std::endl;
ep = edges(g);
ei_end = ep.second;
for (ei = ep.first; ei != ei_end; ++ei){
std::cout << w[*ei] << std::endl;
}
std::cin.get();
}
//------------------------------------------------------------------------
另外,我看到您正在使用vecS,這意味着向量和邊均以固定順序存儲為向量。
您可能只有一個類,用於存儲Edge和Vertex類以及指向該圖的頂點映射或邊緣映射的指針。
我不知道您對這個項目的目標,但是與在幕后管理所有這些增強功能相比,我肯定有更高層次的課程。 意味着將類存儲在具有索引查找的向量中,對於希望使用漂亮的圖類的應用程序將被隱藏和封裝。
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