COIN-OR::LEMON - Graph Library

source: lemon-0.x/demo/steiner_demo.cc @ 2553:bfced05fa852

Last change on this file since 2553:bfced05fa852 was 2553:bfced05fa852, checked in by Alpar Juttner, 11 years ago

Happy New Year to LEMON (+ better update-copyright-header script)

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1/* -*- C++ -*-
2 *
3 * This file is a part of LEMON, a generic C++ optimization library
4 *
5 * Copyright (C) 2003-2008
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///\ingroup demos
20///\file
21///\brief Calculating an approximate Steiner-tree.
22///
23/// Calculating an approximate Steiner-tree.
24///
25/// \include steiner_demo.cc
26
27#include <lemon/smart_graph.h>
28#include <lemon/kruskal.h>
29#include <lemon/graph_reader.h>
30#include <lemon/time_measure.h>
31#include <lemon/graph_to_eps.h>
32
33#include <lemon/steiner.h>
34
35#include <cstdlib>
36#include <cmath>
37
38using namespace lemon;
39using namespace lemon::dim2;
40
41using namespace std;
42
43int main(int argc, const char *argv[]) {
44  std::string lgf = argc > 1 ? argv[1] : "steiner.lgf";
45  std::string eps = argc > 2 ? argv[2] : "steiner.eps";
46
47  SmartUGraph graph;
48  SmartUGraph::NodeMap<bool> terminal(graph);
49  SmartUGraph::NodeMap<int> label(graph);
50  SmartUGraph::NodeMap<Point<double> > coord(graph);
51 
52  UGraphReader<SmartUGraph>(lgf, graph).
53    readNodeMap("coordinates_x", xMap(coord)).
54    readNodeMap("coordinates_y", yMap(coord)).
55    readNodeMap("terminal", terminal).run();
56
57  SmartUGraph::UEdgeMap<double> cost(graph);
58  for (SmartUGraph::UEdgeIt it(graph); it != INVALID; ++it) {
59    cost[it] = sqrt((coord[graph.target(it)] -
60                     coord[graph.source(it)]).normSquare());
61  }
62 
63  SteinerTree<SmartUGraph> steiner(graph, cost);
64  steiner.init();
65
66  for (SmartUGraph::NodeIt it(graph); it != INVALID; ++it) {
67    if (terminal[it]) {
68      steiner.addTerminal(it);
69    }
70  }
71  steiner.start();
72
73
74  Palette nodepalette(0);
75  nodepalette.add(Color(1.0, 1.0, 1.0));
76  nodepalette.add(Color(0.0, 1.0, 0.0));
77  nodepalette.add(Color(0.5, 0.5, 0.5));
78  SmartUGraph::NodeMap<int> nodecolor(graph);
79  for (SmartUGraph::NodeIt it(graph); it != INVALID; ++it) {
80    if (steiner.terminal(it)) {
81      nodecolor[it] = 1;
82    } else if (steiner.steiner(it)) {
83      nodecolor[it] = 2;
84    } else {
85      nodecolor[it] = 0;
86    }
87  }
88
89
90  Palette edgepalette(0);
91  edgepalette.add(Color(0.0, 0.0, 0.0));
92  edgepalette.add(Color(1.0, 0.0, 0.0));
93  SmartUGraph::UEdgeMap<int> edgecolor(graph);
94  for (SmartUGraph::UEdgeIt it(graph); it != INVALID; ++it) {
95    edgecolor[it] = steiner.tree(it) ? 1 : 0;
96  }
97
98
99  graphToEps(graph, eps).
100    coords(coord).undirected().
101    nodeScale(1.0).scaleToA4().
102    nodeColors(composeMap(nodepalette, nodecolor)).
103    edgeColors(composeMap(edgepalette, edgecolor)).
104    nodeTexts(label).nodeTextSize(8).run();
105
106  std::cout << "The tree constructed: " << eps << std::endl;
107  std::cout << "The cost of the tree: " << steiner.treeValue() << std::endl;
108
109  return 0;
110}
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