dust3d/src/shortestpath.cpp

66 lines
2.2 KiB
C++

#include <boost/config.hpp>
#include <iostream>
#include <fstream>
#include <boost/graph/graph_traits.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/dijkstra_shortest_paths.hpp>
#include <QDebug>
#include "shortestpath.h"
using namespace boost;
bool shortestPath(size_t nodeNum,
const std::vector<std::pair<size_t, size_t>> &edges,
const std::vector<int> &weights,
size_t start,
size_t stop,
std::vector<size_t> *path)
{
typedef adjacency_list < listS, vecS, undirectedS,
no_property, property < edge_weight_t, int > > graph_t;
typedef graph_traits < graph_t >::vertex_descriptor vertex_descriptor;
typedef graph_traits < graph_t >::edge_descriptor edge_descriptor;
typedef std::pair<size_t, size_t> Edge;
size_t edgeNum = edges.size();
#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
graph_t g(nodeNum);
property_map<graph_t, edge_weight_t>::type weightmap = get(edge_weight, g);
for (std::size_t j = 0; j < edgeNum; ++j) {
edge_descriptor e; bool inserted;
tie(e, inserted) = add_edge(edges[j].first, edges[j].second, g);
weightmap[e] = weights[j];
}
#else
graph_t g(edges.data(), edges.data() + edgeNum, weights.data(), nodeNum);
property_map<graph_t, edge_weight_t>::type weightmap = get(edge_weight, g);
#endif
std::vector<vertex_descriptor> p(num_vertices(g));
std::vector<size_t> d(num_vertices(g));
vertex_descriptor s = vertex(start, g);
#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
// VC++ has trouble with the named parameters mechanism
property_map<graph_t, vertex_index_t>::type indexmap = get(vertex_index, g);
dijkstra_shortest_paths(g, s, &p[0], &d[0], weightmap, indexmap,
std::less<size_t>(), closed_plus<size_t>(),
(std::numeric_limits<size_t>::max)(), 0,
default_dijkstra_visitor());
#else
dijkstra_shortest_paths(g, s, predecessor_map(&p[0]).distance_map(&d[0]));
#endif
auto current = stop;
while (current != start) {
path->push_back(current);
size_t next = p[current];
if (next == current)
return false;
current = next;
}
path->push_back(current);
return true;
}