c++ - 又一个 BGL 的介数中心性问题

Question

借鉴this回复，我试过如下实现介数中心性:

typedef struct vpr_
{ 
    int id;         
} VProp;
typedef boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, VProp, EProp> graph_t;
boost::shared_array_property_map<double, boost::property_map<graph_t, int>::const_type> centrality_map(num_vertices(g), get(VProp::id, g));

但是返回如下错误。

In file included from /usr/local/include/boost/graph/adjacency_list.hpp:246:0,
             from /usr/local/include/boost/graph/random.hpp:23,
             from ../../src/graph/Graph.h:25,
             from Graph.cpp:23:
/usr/local/include/boost/graph/detail/adjacency_list.hpp: In instantiation of ‘struct boost::adj_list_any_vertex_pa::bind_<int, boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, vpr_, epr_>, vpr_>’:
/usr/local/include/boost/graph/detail/adjacency_list.hpp:2568:12:   required from ‘struct boost::detail::adj_list_choose_vertex_pa<int, boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, vpr_, epr_>, vpr_>’
/usr/local/include/boost/graph/detail/adjacency_list.hpp:2705:12:   required from ‘struct boost::adj_list_vertex_property_selector::bind_<boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, vpr_, epr_>, vpr_, int>’
/usr/local/include/boost/graph/properties.hpp:217:12:   required from ‘struct boost::detail::vertex_property_map<boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, vpr_, epr_>, int>’
/usr/local/include/boost/graph/properties.hpp:228:10:   required from ‘struct boost::property_map<boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, vpr_, epr_>, int>’
Graph.cpp:374:76:   required from here
/usr/local/include/boost/graph/detail/adjacency_list.hpp:2498:29: error: forming reference to void
/usr/local/include/boost/graph/detail/adjacency_list.hpp:2499:35: error: forming reference to void
/usr/local/include/boost/graph/detail/adjacency_list.hpp:2502:47: error: forming reference to void
/usr/local/include/boost/graph/detail/adjacency_list.hpp:2504:53: error: forming reference to void
Graph.cpp: In member function ‘void Graph::getBetweennes()’:
Graph.cpp:374:88: error: template argument 2 is invalid
Graph.cpp:375:17: error: invalid type in declaration before ‘(’ token
In file included from ../../src/graph/graph_t.h:33:0,
             from ../../src/graph/Graph.h:26,
             from Graph.cpp:23:
../../src/graph/VProp.h:38:6: error: invalid use of non-static data member ‘vpr_::id’
Graph.cpp:375:46: error: from this location
Graph.cpp:375:52: error: expression list treated as compound expression in initializer [-fpermissive]

编辑

#include <boost/graph/iteration_macros.hpp>
#include <boost/random/mersenne_twister.hpp>
#include <boost/graph/random.hpp> 

typedef struct vpr_
{ 
    int id;         
} VProp;
typedef struct epr_
{ 
    int id;         
} EProp;
typedef boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, VProp, EProp> graph_t;


int main(void) {
    graph_t g;
    boost::shared_array_property_map<double, boost::property_map<graph_t,  VProp::*>::const_type> centrality_map(num_vertices(g), get(&VProp::id, g));
}

代码已经用g++ -L/usr/local/lib -lboost_graph gtest.cpp编译，返回错误为:

 gtest.cpp: In function ‘int main()’:
 gtest.cpp:18:81: error: template argument 2 is invalid
 gtest.cpp:18:94: error: template argument 2 is invalid
 gtest.cpp:18:110: error: invalid type in declaration before ‘(’ token
 gtest.cpp:18:146: error: expression list treated as compound expression in initializer [-fpermissive]
 gtest.cpp:18:146: error: cannot convert ‘boost::adj_list_any_vertex_pa::bind_<int vpr_::*, boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, vpr_, epr_>, vpr_>::type {aka boost::adj_list_vertex_property_map<boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, vpr_, epr_>, int, int&, int vpr_::*>}’ to ‘int’ in initialization

我该如何解决这个问题？提前致谢

Answer 1

Jackb，与 BGL 中的许多其他算法一样，此 BGL 算法需要“顶点索引属性映射”——图顶点集与区间 [0,num_vertices(g)) 内的整数之间的一对一映射。 .

现在，您的结构 EProp 和 VProp 不能用作 vertex_index 属性映射的替代品，这是导致编译错误的原因。

如果可以使用boost::adjacency_list<boost::vecS, ...>作为您的图表类型，那么 vertex_index 映射将免费(作为图表的内部属性)。然后您将能够按照在您引用的线程中调用它的方式调用中心算法:centrality_map(num_vertices(g), get(boost::vertex_index, g)); .

如果由于某些原因你不能使用 boost::vecS，你必须自己组织映射。对于 setS 和 listS，在这里讨论 How to use boost::graph algorithms with listS, setS as vertex/edge containers?及其引用资料。

在此处查看有关 Property Map 的相关讨论 What is a property map in BOOST?特别是在 vertex_index map 上:Dijkstra Shortest Path with VertexList = ListS in boost graph