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//=======================================================================

// 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)

//=======================================================================

#include <boost/graph/dag_shortest_paths.hpp>

#include <boost/graph/adjacency_list.hpp>

#include <iostream>

// Example from Introduction to Algorithms by Cormen, et all p.537.

// Sample output:

// r: inifinity

// s: 0

// t: 2

// u: 6

// v: 5

// x: 3

int main()

{

using namespace boost;

using graph_t = adjacency_list< vecS, vecS, directedS,

property< vertex_distance_t, int >, property< edge_weight_t, int > >;

graph_t g(6);

enum verts

{

};

char name[] = "rstuvx";

add_edge(r, s, 5, g);

add_edge(r, t, 3, g);

add_edge(s, t, 2, g);

add_edge(s, u, 6, g);

add_edge(t, u, 7, g);

add_edge(t, v, 4, g);

add_edge(t, x, 2, g);

add_edge(u, v, -1, g);

add_edge(u, x, 1, g);

add_edge(v, x, -2, g);

auto d_map = get(vertex_distance, g);

#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300

// VC++ has trouble with the named-parameter mechanism, so

// we make a direct call to the underlying implementation function.

std::vector< default_color_type > color(num_vertices(g));

std::vector< std::size_t > pred(num_vertices(g));

default_dijkstra_visitor vis;

std::less< int > compare;

closed_plus< int > combine;

auto w_map = get(edge_weight, g);

dag_shortest_paths(g, s, d_map, w_map, &color[0], &pred[0], vis, compare,

combine, (std::numeric_limits< int >::max)(), 0);

#else

dag_shortest_paths(g, s, distance_map(d_map));

#endif

graph_traits< graph_t >::vertex_iterator vi, vi_end;

for (boost::tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi)

if (d_map[*vi] == (std::numeric_limits< int >::max)())

std::cout << name[*vi] << ": inifinity\n";

else

std::cout << name[*vi] << ": " << d_map[*vi] << '\n';

return 0;

}