copy_graph - adjacency_list捆绑属性

copy_graph - adjacency_list with bundled properties

本文关键字：属性 list adjacency graph copy      更新时间：2023-10-16

这是一个完整的代码片段，用于复制具有捆绑属性的图形，但会导致一堆编译器错误。解决问题需要什么？

struct NodeInfo1    {};
struct EdgeInfo1 {};
typedef boost::labeled_graph< boost::adjacency_list<
    boost::vecS, boost::vecS, boost::undirectedS, NodeInfo1, EdgeInfo1>,
    std::string> Graph1;
typedef std::pair<boost::graph_traits<Graph>::edge_descriptor, bool> Edge;

void TestCases::TestCopyGraph()
{
    Graph1 grid, g1;
    EdgeInfo1 ei;
    Edge e = add_edge_by_label("A", "B", ei, grid);
    copy_graph(grid, g1);
}
这

有点歪曲了这个问题。您实际上并不是在复制邻接列表，而是在复制labeled_graph适配器，这恰好不满足copy_graph要求的概念：

/** @name Labeled Mutable Graph
 * The labeled mutable graph hides the add_ and remove_ vertex functions from
 * the mutable graph concept. Note that the remove_vertex is hidden because
 * removing the vertex without its key could leave a dangling reference in
 * the map.
 */

以下是复制adjacency_list：¹

typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, NodeInfo1, EdgeInfo1> AList;
typedef boost::labeled_graph<AList, std::string> Graph;
void TestCopyGraph()
{
    std::string names[3] = { "A", "B", "C" };
    Graph grid(3, names);
    EdgeInfo1 ei;
    /*auto e =*/ add_edge_by_label("C", "B", ei, grid);
    AList g1;
    copy_graph(grid, g1);
}

复制带标签的适配器

容易多了。不需要copy_graph，只需复制构造对象：

#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/copy.hpp>
#include <boost/graph/labeled_graph.hpp>
#include <boost/graph/graph_utility.hpp>
struct NodeInfo1 { int i; };
struct EdgeInfo1 { int j; };
typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, NodeInfo1, EdgeInfo1> AList;
typedef boost::labeled_graph<AList, std::string> Graph;
auto TestCopyGraph()
{
    std::string names[3] = { "A", "B", "C" };
      NodeInfo1 props[3] = { {11}, {22}, {33} };
    Graph grid(3, names, props);
    /*auto e =*/ add_edge_by_label("C", "B", EdgeInfo1{17}, grid);
    Graph g1 = grid; // just copy-construct
    return g1;
}
int main() {
    auto copied = TestCopyGraph();
    print_graph(copied);
    // check that properties were copied: vertex B has NodeInfo1 22
    {
        auto pmap = boost::get(&NodeInfo1::i, copied);
        std::cout << "Vertex B NodeInfo1.i after copy: " << pmap[copied.vertex("B")] << "n";
    }
    // edge properties too:
    for (auto e : boost::make_iterator_range(edges(copied)))
        std::cout << "Edge has property EdgeInfo1 " << copied[e].j << "n";
    std::cout << "Removed A:n";
    copied.remove_vertex("A");
    print_graph(copied);
}

指纹

0 <--> 
1 <--> 2 
2 <--> 1 
Vertex B NodeInfo1.i after copy: 22
Edge has property EdgeInfo1 17
Removed A:
0 <--> 1 
1 <--> 0

¹ 请注意，由于 labeled_graph 中的错误，您需要此修补程序：https://github.com/boostorg/graph/pull/58

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