Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is the documentation for a snapshot of the master branch, built from commit 2d55b6d6f1.

libs/graph/example/undirected_adjacency_list.cpp

//=======================================================================
// Copyright 2001 Jeremy G. Siek, Andrew Lumsdaine, Lie-Quan Lee,
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//=======================================================================
#include <boost/config.hpp>
#include <iostream>
#include <boost/graph/adjacency_list.hpp>
using namespace boost;

template < typename UndirectedGraph > void undirected_graph_demo1()
{
    const int V = 3;
    UndirectedGraph undigraph(V);
    typename graph_traits< UndirectedGraph >::vertex_descriptor zero, one, two;
    typename graph_traits< UndirectedGraph >::out_edge_iterator out, out_end;
    typename graph_traits< UndirectedGraph >::in_edge_iterator in, in_end;

    zero = vertex(0, undigraph);
    one = vertex(1, undigraph);
    two = vertex(2, undigraph);
    add_edge(zero, one, undigraph);
    add_edge(zero, two, undigraph);
    add_edge(one, two, undigraph);

    std::cout << "out_edges(0):";
    for (boost::tie(out, out_end) = out_edges(zero, undigraph); out != out_end;
         ++out)
        std::cout << ' ' << *out;
    std::cout << std::endl << "in_edges(0):";
    for (boost::tie(in, in_end) = in_edges(zero, undigraph); in != in_end; ++in)
        std::cout << ' ' << *in;
    std::cout << std::endl;
}

template < typename DirectedGraph > void directed_graph_demo()
{
    const int V = 2;
    DirectedGraph digraph(V);
    typename graph_traits< DirectedGraph >::vertex_descriptor u, v;
    typedef typename DirectedGraph::edge_property_type Weight;
    typename property_map< DirectedGraph, edge_weight_t >::type weight
        = get(edge_weight, digraph);
    typename graph_traits< DirectedGraph >::edge_descriptor e1, e2;
    bool found;

    u = vertex(0, digraph);
    v = vertex(1, digraph);
    add_edge(u, v, Weight(1.2), digraph);
    add_edge(v, u, Weight(2.4), digraph);
    boost::tie(e1, found) = edge(u, v, digraph);
    boost::tie(e2, found) = edge(v, u, digraph);
    std::cout << "in a directed graph is ";
#ifdef __GNUC__
    // no boolalpha
    std::cout << "(u,v) == (v,u) ? " << (e1 == e2) << std::endl;
#else
    std::cout << "(u,v) == (v,u) ? " << std::boolalpha << (e1 == e2)
              << std::endl;
#endif
    std::cout << "weight[(u,v)] = " << get(weight, e1) << std::endl;
    std::cout << "weight[(v,u)] = " << get(weight, e2) << std::endl;
}

template < typename UndirectedGraph > void undirected_graph_demo2()
{
    const int V = 2;
    UndirectedGraph undigraph(V);
    typename graph_traits< UndirectedGraph >::vertex_descriptor u, v;
    typedef typename UndirectedGraph::edge_property_type Weight;
    typename property_map< UndirectedGraph, edge_weight_t >::type weight
        = get(edge_weight, undigraph);
    typename graph_traits< UndirectedGraph >::edge_descriptor e1, e2;
    bool found;

    u = vertex(0, undigraph);
    v = vertex(1, undigraph);
    add_edge(u, v, Weight(3.1), undigraph);
    boost::tie(e1, found) = edge(u, v, undigraph);
    boost::tie(e2, found) = edge(v, u, undigraph);
    std::cout << "in an undirected graph is ";
#ifdef __GNUC__
    std::cout << "(u,v) == (v,u) ? " << (e1 == e2) << std::endl;
#else
    std::cout << "(u,v) == (v,u) ? " << std::boolalpha << (e1 == e2)
              << std::endl;
#endif
    std::cout << "weight[(u,v)] = " << get(weight, e1) << std::endl;
    std::cout << "weight[(v,u)] = " << get(weight, e2) << std::endl;

    std::cout << "the edges incident to v: ";
    typename boost::graph_traits< UndirectedGraph >::out_edge_iterator e, e_end;
    typename boost::graph_traits< UndirectedGraph >::vertex_descriptor s
        = vertex(0, undigraph);
    for (boost::tie(e, e_end) = out_edges(s, undigraph); e != e_end; ++e)
        std::cout << "(" << source(*e, undigraph) << ","
                  << target(*e, undigraph) << ")" << std::endl;
}

int main()
{
    typedef property< edge_weight_t, double > Weight;
    typedef adjacency_list< vecS, vecS, undirectedS, no_property, Weight >
        UndirectedGraph;
    typedef adjacency_list< vecS, vecS, directedS, no_property, Weight >
        DirectedGraph;
    undirected_graph_demo1< UndirectedGraph >();
    directed_graph_demo< DirectedGraph >();
    undirected_graph_demo2< UndirectedGraph >();
    return 0;
}