1 | /* -*- C++ -*- |
---|
2 | * |
---|
3 | * This file is a part of LEMON, a generic C++ optimization library |
---|
4 | * |
---|
5 | * Copyright (C) 2003-2006 |
---|
6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
---|
7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
---|
8 | * |
---|
9 | * Permission to use, modify and distribute this software is granted |
---|
10 | * provided that this copyright notice appears in all copies. For |
---|
11 | * precise terms see the accompanying LICENSE file. |
---|
12 | * |
---|
13 | * This software is provided "AS IS" with no warranty of any kind, |
---|
14 | * express or implied, and with no claim as to its suitability for any |
---|
15 | * purpose. |
---|
16 | * |
---|
17 | */ |
---|
18 | |
---|
19 | #include <iostream> |
---|
20 | #include <fstream> |
---|
21 | |
---|
22 | #include <lemon/smart_graph.h> |
---|
23 | #include <lemon/dijkstra.h> |
---|
24 | #include <lemon/maps.h> |
---|
25 | #include <lemon/dim2.h> |
---|
26 | #include <lemon/graph_reader.h> |
---|
27 | |
---|
28 | #include <lemon/time_measure.h> |
---|
29 | |
---|
30 | #include <cmath> |
---|
31 | |
---|
32 | /// \ingroup demos |
---|
33 | /// \file |
---|
34 | /// \brief Minimal route on a planar graph with eucledian distances. |
---|
35 | /// |
---|
36 | /// Minimal route on a planar graph with eucledian distances. |
---|
37 | /// |
---|
38 | /// \include min_route.cc |
---|
39 | |
---|
40 | |
---|
41 | using namespace lemon; |
---|
42 | |
---|
43 | template <typename CoordMap> |
---|
44 | class PotentialMap { |
---|
45 | public: |
---|
46 | typedef double Value; |
---|
47 | typedef typename CoordMap::Key Key; |
---|
48 | |
---|
49 | PotentialMap(const CoordMap& _coord, const dim2::Point<double>& _target) |
---|
50 | : coord(_coord), target(_target) {} |
---|
51 | |
---|
52 | double operator[](const Key& node) const { |
---|
53 | return std::sqrt((coord[node].x - target.x) * (coord[node].x - target.x) + |
---|
54 | (coord[node].y - target.y) * (coord[node].y - target.y)); |
---|
55 | } |
---|
56 | private: |
---|
57 | const CoordMap& coord; |
---|
58 | dim2::Point<double> target; |
---|
59 | }; |
---|
60 | |
---|
61 | template <typename Graph, typename LengthMap, typename PotentialMap> |
---|
62 | class ReducedLengthMap { |
---|
63 | public: |
---|
64 | typedef double Value; |
---|
65 | typedef typename LengthMap::Key Key; |
---|
66 | |
---|
67 | ReducedLengthMap(const Graph& _graph, const LengthMap& _length, |
---|
68 | const PotentialMap& _pot) |
---|
69 | : graph(_graph), length(_length), pot(_pot) {} |
---|
70 | |
---|
71 | Value operator[](const Key& edge) const { |
---|
72 | return length[edge] - (pot[graph.source(edge)] - pot[graph.target(edge)]); |
---|
73 | } |
---|
74 | |
---|
75 | private: |
---|
76 | const Graph& graph; |
---|
77 | const LengthMap& length; |
---|
78 | const PotentialMap& pot; |
---|
79 | }; |
---|
80 | |
---|
81 | int main() { |
---|
82 | typedef SmartGraph Graph; |
---|
83 | |
---|
84 | typedef Graph::Edge Edge; |
---|
85 | typedef Graph::Node Node; |
---|
86 | typedef Graph::EdgeIt EdgeIt; |
---|
87 | typedef Graph::NodeIt NodeIt; |
---|
88 | typedef Graph::EdgeMap<double> LengthMap; |
---|
89 | typedef Graph::NodeMap<dim2::Point<double> > CoordMap; |
---|
90 | |
---|
91 | SmartGraph graph; |
---|
92 | |
---|
93 | std::ifstream is("route.lgf"); |
---|
94 | GraphReader<Graph> reader(is, graph); |
---|
95 | |
---|
96 | CoordMap coord(graph); |
---|
97 | dim2::XMap<CoordMap> xcoord = xMap(coord); |
---|
98 | reader.readNodeMap("coordinates_x", xcoord); |
---|
99 | dim2::YMap<CoordMap> ycoord = yMap(coord); |
---|
100 | reader.readNodeMap("coordinates_y", ycoord); |
---|
101 | |
---|
102 | LengthMap length(graph); |
---|
103 | reader.readEdgeMap("length", length); |
---|
104 | |
---|
105 | Node source, target; |
---|
106 | reader.readNode("source", source); |
---|
107 | reader.readNode("target", target); |
---|
108 | |
---|
109 | reader.run(); |
---|
110 | |
---|
111 | { |
---|
112 | Timer timer; |
---|
113 | Dijkstra<Graph, LengthMap> dijkstra(graph, length); |
---|
114 | dijkstra.init(); |
---|
115 | dijkstra.addSource(source); |
---|
116 | dijkstra.start(target); |
---|
117 | |
---|
118 | std::cout << dijkstra.dist(target) << std::endl; |
---|
119 | std::cout << timer << std::endl; |
---|
120 | } |
---|
121 | { |
---|
122 | Timer timer; |
---|
123 | typedef PotentialMap<CoordMap> Potential; |
---|
124 | Potential potential(coord, coord[target]); |
---|
125 | |
---|
126 | typedef ReducedLengthMap<Graph, LengthMap, Potential> ReducedLength; |
---|
127 | ReducedLength reduced(graph, length, potential); |
---|
128 | |
---|
129 | Dijkstra<Graph, ReducedLength> dijkstra(graph, reduced); |
---|
130 | |
---|
131 | dijkstra.init(); |
---|
132 | dijkstra.addSource(source); |
---|
133 | dijkstra.start(target); |
---|
134 | |
---|
135 | std::cout << dijkstra.dist(target) + potential[source] << std::endl; |
---|
136 | std::cout << timer << std::endl; |
---|
137 | } |
---|
138 | |
---|
139 | return 0; |
---|
140 | } |
---|