MapSelector has become a standalone class.
2 * demo/min_route.cc - Part of LEMON, a generic C++ optimization library
4 * Copyright (C) 2006 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
5 * (Egervary Research Group on Combinatorial Optimization, EGRES).
7 * Permission to use, modify and distribute this software is granted
8 * provided that this copyright notice appears in all copies. For
9 * precise terms see the accompanying LICENSE file.
11 * This software is provided "AS IS" with no warranty of any kind,
12 * express or implied, and with no claim as to its suitability for any
20 #include <lemon/smart_graph.h>
21 #include <lemon/dijkstra.h>
22 #include <lemon/maps.h>
24 #include <lemon/graph_reader.h>
26 #include <lemon/time_measure.h>
32 /// \brief Minimal route on a plan graph with eucledian distances.
34 /// Minimal route on a plan graph with eucledian distances.
36 /// \include min_route.cc
39 using namespace lemon;
41 template <typename CoordMap>
45 typedef typename CoordMap::Key Key;
47 PotentialMap(const CoordMap& _coord, const xy<double>& _target)
48 : coord(_coord), target(_target) {}
50 double operator[](const Key& node) const {
51 return std::sqrt((coord[node].x - target.x) * (coord[node].x - target.x) +
52 (coord[node].y - target.y) * (coord[node].y - target.y));
55 const CoordMap& coord;
59 template <typename Graph, typename LengthMap, typename PotentialMap>
60 class ReducedLengthMap {
63 typedef typename LengthMap::Key Key;
65 ReducedLengthMap(const Graph& _graph, const LengthMap& _length,
66 const PotentialMap& _pot)
67 : graph(_graph), length(_length), pot(_pot) {}
69 Value operator[](const Key& edge) const {
70 return length[edge] - (pot[graph.source(edge)] - pot[graph.target(edge)]);
75 const LengthMap& length;
76 const PotentialMap& pot;
80 typedef SmartGraph Graph;
82 typedef Graph::Edge Edge;
83 typedef Graph::Node Node;
84 typedef Graph::EdgeIt EdgeIt;
85 typedef Graph::NodeIt NodeIt;
86 typedef Graph::EdgeMap<double> LengthMap;
87 typedef Graph::NodeMap<xy<double> > CoordMap;
91 std::ifstream is("route.lgf");
92 GraphReader<Graph> reader(is, graph);
94 CoordMap coord(graph);
95 XMap<CoordMap> xcoord = xMap(coord);
96 reader.readNodeMap("coordinates_x", xcoord);
97 YMap<CoordMap> ycoord = yMap(coord);
98 reader.readNodeMap("coordinates_y", ycoord);
100 LengthMap length(graph);
101 reader.readEdgeMap("length", length);
104 reader.readNode("source", source);
105 reader.readNode("target", target);
111 Dijkstra<Graph, LengthMap> dijkstra(graph, length);
113 dijkstra.addSource(source);
114 dijkstra.start(target);
116 std::cout << dijkstra.dist(target) << std::endl;
117 std::cout << timer << std::endl;
121 typedef PotentialMap<CoordMap> Potential;
122 Potential potential(coord, coord[target]);
124 typedef ReducedLengthMap<Graph, LengthMap, Potential> ReducedLength;
125 ReducedLength reduced(graph, length, potential);
127 Dijkstra<Graph, ReducedLength> dijkstra(graph, reduced);
130 dijkstra.addSource(source);
131 dijkstra.start(target);
133 std::cout << dijkstra.dist(target) + potential[source] << std::endl;
134 std::cout << timer << std::endl;