Boost C++ Libraries

libs/graph/example/dfs_parenthesis.cpp

//=======================================================================
// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
//
// 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)
//=======================================================================
//
//  Sample output
//  DFS parenthesis:
//  (0(2(3(4(11)4)3)2)0)

#include <boost/config.hpp>
#include <assert.h>
#include <iostream>

#include <vector>
#include <algorithm>
#include <utility>

#include "boost/graph/visitors.hpp"
#include "boost/graph/adjacency_list.hpp"
#include "boost/graph/breadth_first_search.hpp"
#include "boost/graph/depth_first_search.hpp"

using namespace boost;
using namespace std;

struct open_paren : public base_visitor< open_paren >
{
    typedef on_discover_vertex event_filter;
    template < class Vertex, class Graph > void operator()(Vertex v, Graph&)
    {
        std::cout << "(" << v;
    }
};
struct close_paren : public base_visitor< close_paren >
{
    typedef on_finish_vertex event_filter;
    template < class Vertex, class Graph > void operator()(Vertex v, Graph&)
    {
        std::cout << v << ")";
    }
};

int main(int, char*[])
{

    using namespace boost;

    typedef adjacency_list<> Graph;
    typedef std::pair< int, int > E;
    E edge_array[] = { E(0, 2), E(1, 1), E(1, 3), E(2, 1), E(2, 3), E(3, 1),
        E(3, 4), E(4, 0), E(4, 1) };
#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
    Graph G(5);
    for (std::size_t j = 0; j < sizeof(edge_array) / sizeof(E); ++j)
        add_edge(edge_array[j].first, edge_array[j].second, G);
#else
    Graph G(edge_array, edge_array + sizeof(edge_array) / sizeof(E), 5);
#endif

    std::cout << "DFS parenthesis:" << std::endl;
    depth_first_search(G,
        visitor(make_dfs_visitor(std::make_pair(open_paren(), close_paren()))));
    std::cout << std::endl;
    return 0;
}