boost::graph学习

boost::graph API简单小结

boost::graph是boost为图算法提供的API，简单易用。

API说明

1. boost::add_vertex
   创建一个顶点。

2. boost::add_edge
   创建一条边。

3. boost::edges
   获取所有的边。

4. boost::vertices
   获取所有的顶点。

5. graph.operator[vertex_descriptor]
   获取顶点的属性Property。

6. graph.operator[edge_descriptor]
   获取边的属性Property。

7. boost::out_edges
   获取顶点的“出边”（out edges），即以当前顶点为出发点的边。

参考文档：
https://theboostcpplibraries.com/boost.graph-algorithms
https://zhuanlan.zhihu.com/p/338279100
https://www.boost.org/doc/libs/1_83_0/libs/graph/doc/quick_tour.html
https://www.boost.org/doc/libs/1_83_0/libs/graph/doc/adjacency_list.html
https://www.technical-recipes.com/2015/getting-started-with-the-boost-graph-library/
https://blog.csdn.net/Augusdi/article/details/105757441

代码示例：

#include "PSParametricModelingEngine.h"

#include <QDebug>
#include <algorithm>
#include <iostream>
#include <iterator>
#include <utility>

using namespace std;
using namespace boost;

namespace
{
    struct VertexProperty
    {
        int id;
        string name;
    };

    struct EdgeProperty
    {
        int id;
        int weight;
    };

    typedef boost::adjacency_list<vecS,           // 使用数组来存储vertex vecS,
                                  vecS,           // 使用数组来存储vertex vecS,
                                  directedS,      // 申明为有向图，可以访问其out-edge,若要都能访问
                                  VertexProperty, // 定义顶点属性
                                  EdgeProperty    // 定义边的属性
                                  >
        PSGraph;

    typedef graph_traits<PSGraph>::vertex_descriptor vertex_descriptor_t;

    void printVertices()
    {
        boost::adjacency_list<> g;

        boost::adjacency_list<>::vertex_descriptor v1 = boost::add_vertex(g);
        boost::adjacency_list<>::vertex_descriptor v2 = boost::add_vertex(g);
        boost::adjacency_list<>::vertex_descriptor v3 = boost::add_vertex(g);
        boost::adjacency_list<>::vertex_descriptor v4 = boost::add_vertex(g);

        std::cout << v1 << ", " << v2 << ", " << v3 << ", " << v4 << '\n';
    }
    
    void printEdgeVector()
    {
        boost::adjacency_list<> g;

        boost::adjacency_list<>::vertex_descriptor v1 = boost::add_vertex(g);
        boost::adjacency_list<>::vertex_descriptor v2 = boost::add_vertex(g);
        boost::add_vertex(g);
        boost::add_vertex(g);

        std::pair<boost::adjacency_list<>::edge_descriptor, bool> p = boost::add_edge(v1, v2, g);
        std::cout.setf(std::ios::boolalpha);
        std::cout << p.second << '\n';

        p = boost::add_edge(v1, v2, g);
        std::cout << p.second << '\n';

        p = boost::add_edge(v2, v1, g);
        std::cout << p.second << '\n';

        std::pair<boost::adjacency_list<>::edge_iterator, boost::adjacency_list<>::edge_iterator> es = boost::edges(g);

        std::copy(
            es.first, es.second, std::ostream_iterator<boost::adjacency_list<>::edge_descriptor>{std::cout, "\n"});

       for (boost::adjacency_list<>::edge_iterator iterator = es.first; iterator != es.second; iterator++)
        {
            std::stringstream ss;
            ss << (*iterator);

            qDebug() << QString::fromUtf8(ss.str().c_str());
        }
    }

    void printEdgeSet()
    {
        typedef boost::adjacency_list<boost::setS, boost::vecS, boost::undirectedS> graph;
        graph g;

        boost::adjacency_list<>::vertex_descriptor v1 = boost::add_vertex(g);
        boost::adjacency_list<>::vertex_descriptor v2 = boost::add_vertex(g);
        boost::add_vertex(g);
        boost::add_vertex(g);

        std::pair<graph::edge_descriptor, bool> p = boost::add_edge(v1, v2, g);
        std::cout.setf(std::ios::boolalpha);
        std::cout << p.second << '\n';

        p = boost::add_edge(v1, v2, g);
        std::cout << p.second << '\n';

        p = boost::add_edge(v2, v1, g);
        std::cout << p.second << '\n';

        std::pair<graph::edge_iterator, graph::edge_iterator> es = boost::edges(g);

        std::copy(es.first, es.second, std::ostream_iterator<graph::edge_descriptor>{std::cout, "\n"});

        for (graph::edge_iterator iterator = es.first; iterator != es.second; iterator++)
        {
            std::stringstream ss;
            ss << (*iterator);

            qDebug() << QString::fromUtf8(ss.str().c_str());
        }
    }

    int printDirectedGraph()
    {
        // 定义图类型，使用vector存放顶点和边，有向图
        typedef adjacency_list<vecS, vecS, directedS> graph_t;

        // 产生图对象，有6个顶点
        graph_t g(6);

        // 加入边
        add_edge(1, 2, g);
        add_edge(1, 5, g);
        add_edge(2, 2, g);
        add_edge(2, 0, g);
        add_edge(3, 4, g);
        add_edge(4, 3, g);
        add_edge(5, 0, g);

        // 显示所有的顶点
        // 顶点迭代器类型
        typedef graph_traits<graph_t>::vertex_iterator vertex_iter;
        // 得到所有顶点，vrange中的一对迭代器分别指向第一个顶点和最后的一个顶点之后。
        std::pair<vertex_iter, vertex_iter> vrange = vertices(g);
        for (vertex_iter itr = vrange.first; itr != vrange.second; ++itr)
            qDebug() << *itr;

        // 显示所有的边
        // 边迭代器类型
        typedef graph_traits<graph_t>::edge_iterator edge_iter;
        // 得到所有边，erange中的一对迭代器分别指向第一条边和最后的一条边之后
        std::pair<edge_iter, edge_iter> erange = edges(g);
       for (edge_iter itr = erange.first; itr != erange.second; ++itr)
            qDebug() << source(*itr, g) << "-->" << target(*itr, g);

        return 0;
    };

    void printPSGraph()
    {
        PSGraph g; // 声明一个图

        VertexProperty vertex1{101, "Vertex 1"};
        VertexProperty vertex2{102, "Vertex 2"};
        VertexProperty vertex3{103, "Vertex 3"};
        VertexProperty vertex4{104, "Vertex 4"};

        EdgeProperty edge1{101, 1};
        EdgeProperty edge2{102, 2};
        EdgeProperty edge3{103, 3};
        EdgeProperty edge4{104, 4};
        EdgeProperty edge5{105, 5};
        EdgeProperty edge6{106, 6};

        vertex_descriptor_t vert1 = boost::add_vertex(vertex1, g);
        vertex_descriptor_t vert2 = boost::add_vertex(vertex2, g);
        vertex_descriptor_t vert3 = boost::add_vertex(vertex3, g);
        vertex_descriptor_t vert4 = boost::add_vertex(vertex4, g);

        auto e1 = boost::add_edge(vert1, vert2, edge1, g);
        auto e2 = boost::add_edge(vert2, vert3, edge2, g);
        auto e3 = boost::add_edge(vert3, vert4, edge3, g);
        auto e4 = boost::add_edge(vert4, vert1, edge4, g);
        auto e5 = boost::add_edge(vert4, vert2, edge5, g);
        auto e6 = boost::add_edge(vert4, vert3, edge6, g);

        typedef graph_traits<PSGraph>::vertex_iterator vertex_iter;
        std::pair<vertex_iter, vertex_iter> vrange = vertices(g);
        for (vertex_iter itr = vrange.first; itr != vrange.second; ++itr)
        {
            auto prop = g[*itr];
            qDebug() << *itr << ": {" << prop.id << ", " << QString::fromUtf8(prop.name.c_str()) << "}";

            typedef graph_traits<PSGraph> GraphTraits;
            typename GraphTraits::out_edge_iterator out_i, out_end;
            typename GraphTraits::edge_descriptor e;
            for (boost::tie(out_i, out_end) = out_edges(*itr, g); out_i != out_end; ++out_i)
            {
                e = *out_i;
                auto prop = g[e];
                qDebug() << source(e, g) << "-->" << target(e, g) << ": {" << prop.id << ", " << prop.weight << "}";
            }
        }

        typedef graph_traits<PSGraph>::edge_iterator edge_iter;
        std::pair<edge_iter, edge_iter> erange = edges(g);
        for (edge_iter itr = erange.first; itr != erange.second; ++itr)
        {
            auto prop = g[*itr];
            qDebug() << source(*itr, g) << "-->" << target(*itr, g) << ": {" << prop.id << ", " << prop.weight << "}";
        }
    }
} // namespace

void main()
{
    // printEdgeSet();
    // printDirectedGraph();
    printPSGraph();
}