COIN-OR::LEMON - Graph Library

source: lemon/test/tsp_test.cc @ 1270:dceba191c00d

Last change on this file since 1270:dceba191c00d was 1270:dceba191c00d, checked in by Alpar Juttner <alpar@…>, 6 years ago

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1/* -*- mode: C++; indent-tabs-mode: nil; -*-
2 *
3 * This file is a part of LEMON, a generic C++ optimization library.
4 *
5 * Copyright (C) 2003-2013
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
21#include <lemon/full_graph.h>
22#include <lemon/math.h>
23#include <lemon/maps.h>
24#include <lemon/random.h>
25#include <lemon/dim2.h>
26
27#include <lemon/nearest_neighbor_tsp.h>
28#include <lemon/greedy_tsp.h>
29#include <lemon/insertion_tsp.h>
30#include <lemon/christofides_tsp.h>
31#include <lemon/opt2_tsp.h>
32
33#include "test_tools.h"
34
35using namespace lemon;
36
37// // Tests checkMetricCost() function
38// void metricCostTest() {
39//   GRAPH_TYPEDEFS(FullGraph);
40//   FullGraph g(10);
41//   check(checkMetricCost(g, constMap<Edge>(0)), "Wrong checkMetricCost()");
42//   check(checkMetricCost(g, constMap<Edge>(1)), "Wrong checkMetricCost()");
43//   check(!checkMetricCost(g, constMap<Edge>(-1)), "Wrong checkMetricCost()");
44//
45//   FullGraph::EdgeMap<float> cost(g);
46//   for (NodeIt u(g); u != INVALID; ++u) {
47//     for (NodeIt v(g); v != INVALID; ++v) {
48//       if (u == v) continue;
49//       float x1 = g.id(u), x2 = g.id(v);
50//       float y1 = x1 * x1, y2 = x2 * x2;
51//       cost[g.edge(u, v)] = std::sqrt((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1));
52//     }
53//   }
54//   check(checkMetricCost(g, cost), "Wrong checkMetricCost()");
55//   float eps = Tolerance<float>::defaultEpsilon();
56//   cost[g.edge(g(0), g(9))] =
57//     cost[g.edge(g(0), g(8))] + cost[g.edge(g(8), g(9))] + eps * 2;
58//   check(!checkMetricCost(g, cost), "Wrong checkMetricCost()");
59//   check(checkMetricCost(g, cost, Tolerance<float>(eps * 4)),
60//     "Wrong checkMetricCost()");
61// }
62
63// Checks tour validity
64template <typename Container>
65bool checkTour(const FullGraph &gr, const Container &p) {
66  FullGraph::NodeMap<bool> used(gr, false);
67
68  int node_cnt = 0;
69  for (typename Container::const_iterator it = p.begin(); it != p.end(); ++it) {
70    FullGraph::Node node = *it;
71    if (used[node]) return false;
72    used[node] = true;
73    ++node_cnt;
74  }
75
76  return (node_cnt == gr.nodeNum());
77}
78
79// Checks tour validity
80bool checkTourPath(const FullGraph &gr, const Path<FullGraph> &p) {
81  FullGraph::NodeMap<bool> used(gr, false);
82
83  if (!checkPath(gr, p)) return false;
84  if (gr.nodeNum() <= 1 && p.length() != 0) return false;
85  if (gr.nodeNum() > 1 && p.length() != gr.nodeNum()) return false;
86
87  for (int i = 0; i < p.length(); ++i) {
88    if (used[gr.target(p.nth(i))]) return false;
89    used[gr.target(p.nth(i))] = true;
90  }
91  return true;
92}
93
94// Checks tour cost
95template <typename CostMap>
96bool checkCost(const FullGraph &gr, const std::vector<FullGraph::Node> &p,
97               const CostMap &cost, typename CostMap::Value total)
98{
99  typedef typename CostMap::Value Cost;
100
101  Cost s = 0;
102  for (int i = 0; i < int(p.size()) - 1; ++i)
103    s += cost[gr.edge(p[i], p[i+1])];
104  if (int(p.size()) >= 2)
105    s += cost[gr.edge(p.back(), p.front())];
106
107  return !Tolerance<Cost>().different(s, total);
108}
109
110// Checks tour cost
111template <typename CostMap>
112bool checkCost(const FullGraph &, const Path<FullGraph> &p,
113               const CostMap &cost, typename CostMap::Value total)
114{
115  typedef typename CostMap::Value Cost;
116
117  Cost s = 0;
118  for (int i = 0; i < p.length(); ++i)
119    s += cost[p.nth(i)];
120
121  return !Tolerance<Cost>().different(s, total);
122}
123
124// Tests a TSP algorithm on small graphs
125template <typename TSP>
126void tspTestSmall(const std::string &alg_name) {
127  GRAPH_TYPEDEFS(FullGraph);
128
129  for (int n = 0; n <= 5; ++n) {
130    FullGraph g(n);
131    unsigned nsize = n;
132    int esize = n <= 1 ? 0 : n;
133
134    TSP alg(g, constMap<Edge, int>(1));
135
136    check(alg.run() == esize, alg_name + ": Wrong total cost");
137    check(alg.tourCost() == esize, alg_name + ": Wrong total cost");
138
139    std::list<Node> list1(nsize), list2;
140    std::vector<Node> vec1(nsize), vec2;
141    alg.tourNodes(list1.begin());
142    alg.tourNodes(vec1.begin());
143    alg.tourNodes(std::front_inserter(list2));
144    alg.tourNodes(std::back_inserter(vec2));
145    check(checkTour(g, alg.tourNodes()), alg_name + ": Wrong node sequence");
146    check(checkTour(g, list1), alg_name + ": Wrong node sequence");
147    check(checkTour(g, vec1), alg_name + ": Wrong node sequence");
148    check(checkTour(g, list2), alg_name + ": Wrong node sequence");
149    check(checkTour(g, vec2), alg_name + ": Wrong node sequence");
150    check(checkCost(g, vec1, constMap<Edge, int>(1), esize),
151      alg_name + ": Wrong tour cost");
152
153    SimplePath<FullGraph> path;
154    alg.tour(path);
155    check(path.length() == esize, alg_name + ": Wrong tour");
156    check(checkTourPath(g, path), alg_name + ": Wrong tour");
157    check(checkCost(g, path, constMap<Edge, int>(1), esize),
158      alg_name + ": Wrong tour cost");
159  }
160}
161
162// Tests a TSP algorithm on random graphs
163template <typename TSP>
164void tspTestRandom(const std::string &alg_name) {
165  GRAPH_TYPEDEFS(FullGraph);
166
167  FullGraph g(20);
168  FullGraph::NodeMap<dim2::Point<double> > pos(g);
169  DoubleEdgeMap cost(g);
170
171  TSP alg(g, cost);
172  Opt2Tsp<DoubleEdgeMap > opt2(g, cost);
173
174  for (int i = 1; i <= 3; i++) {
175    for (NodeIt u(g); u != INVALID; ++u) {
176      pos[u] = dim2::Point<double>(rnd(), rnd());
177    }
178    for (NodeIt u(g); u != INVALID; ++u) {
179      for (NodeIt v(g); v != INVALID; ++v) {
180        if (u == v) continue;
181        cost[g.edge(u, v)] = (pos[u] - pos[v]).normSquare();
182      }
183    }
184
185    check(alg.run() > 0, alg_name + ": Wrong total cost");
186
187    std::vector<Node> vec;
188    alg.tourNodes(std::back_inserter(vec));
189    check(checkTour(g, vec), alg_name + ": Wrong node sequence");
190    check(checkCost(g, vec, cost, alg.tourCost()),
191      alg_name + ": Wrong tour cost");
192
193    SimplePath<FullGraph> path;
194    alg.tour(path);
195    check(checkTourPath(g, path), alg_name + ": Wrong tour");
196    check(checkCost(g, path, cost, alg.tourCost()),
197      alg_name + ": Wrong tour cost");
198
199    check(!Tolerance<double>().less(alg.tourCost(), opt2.run(alg.tourNodes())),
200      "2-opt improvement: Wrong total cost");
201    check(checkTour(g, opt2.tourNodes()),
202      "2-opt improvement: Wrong node sequence");
203    check(checkCost(g, opt2.tourNodes(), cost, opt2.tourCost()),
204      "2-opt improvement: Wrong tour cost");
205
206    check(!Tolerance<double>().less(alg.tourCost(), opt2.run(path)),
207      "2-opt improvement: Wrong total cost");
208    check(checkTour(g, opt2.tourNodes()),
209      "2-opt improvement: Wrong node sequence");
210    check(checkCost(g, opt2.tourNodes(), cost, opt2.tourCost()),
211      "2-opt improvement: Wrong tour cost");
212  }
213}
214
215// Algorithm class for Nearest Insertion
216template <typename CM>
217class NearestInsertionTsp : public InsertionTsp<CM> {
218public:
219  NearestInsertionTsp(const FullGraph &gr, const CM &cost)
220    : InsertionTsp<CM>(gr, cost) {}
221  typename CM::Value run() {
222    return InsertionTsp<CM>::run(InsertionTsp<CM>::NEAREST);
223  }
224};
225
226// Algorithm class for Farthest Insertion
227template <typename CM>
228class FarthestInsertionTsp : public InsertionTsp<CM> {
229public:
230  FarthestInsertionTsp(const FullGraph &gr, const CM &cost)
231    : InsertionTsp<CM>(gr, cost) {}
232  typename CM::Value run() {
233    return InsertionTsp<CM>::run(InsertionTsp<CM>::FARTHEST);
234  }
235};
236
237// Algorithm class for Cheapest Insertion
238template <typename CM>
239class CheapestInsertionTsp : public InsertionTsp<CM> {
240public:
241  CheapestInsertionTsp(const FullGraph &gr, const CM &cost)
242    : InsertionTsp<CM>(gr, cost) {}
243  typename CM::Value run() {
244    return InsertionTsp<CM>::run(InsertionTsp<CM>::CHEAPEST);
245  }
246};
247
248// Algorithm class for Random Insertion
249template <typename CM>
250class RandomInsertionTsp : public InsertionTsp<CM> {
251public:
252  RandomInsertionTsp(const FullGraph &gr, const CM &cost)
253    : InsertionTsp<CM>(gr, cost) {}
254  typename CM::Value run() {
255    return InsertionTsp<CM>::run(InsertionTsp<CM>::RANDOM);
256  }
257};
258
259int main() {
260  GRAPH_TYPEDEFS(FullGraph);
261
262  // metricCostTest();
263
264  tspTestSmall<NearestNeighborTsp<ConstMap<Edge, int> > >("Nearest Neighbor");
265  tspTestSmall<GreedyTsp<ConstMap<Edge, int> > >("Greedy");
266  tspTestSmall<NearestInsertionTsp<ConstMap<Edge, int> > >("Nearest Insertion");
267  tspTestSmall<FarthestInsertionTsp<ConstMap<Edge, int> > >("Farthest Insertion");
268  tspTestSmall<CheapestInsertionTsp<ConstMap<Edge, int> > >("Cheapest Insertion");
269  tspTestSmall<RandomInsertionTsp<ConstMap<Edge, int> > >("Random Insertion");
270  tspTestSmall<ChristofidesTsp<ConstMap<Edge, int> > >("Christofides");
271  tspTestSmall<Opt2Tsp<ConstMap<Edge, int> > >("2-opt");
272
273  tspTestRandom<NearestNeighborTsp<DoubleEdgeMap > >("Nearest Neighbor");
274  tspTestRandom<GreedyTsp<DoubleEdgeMap > >("Greedy");
275  tspTestRandom<NearestInsertionTsp<DoubleEdgeMap > >("Nearest Insertion");
276  tspTestRandom<FarthestInsertionTsp<DoubleEdgeMap > >("Farthest Insertion");
277  tspTestRandom<CheapestInsertionTsp<DoubleEdgeMap > >("Cheapest Insertion");
278  tspTestRandom<RandomInsertionTsp<DoubleEdgeMap > >("Random Insertion");
279  tspTestRandom<ChristofidesTsp<DoubleEdgeMap > >("Christofides");
280  tspTestRandom<Opt2Tsp<DoubleEdgeMap > >("2-opt");
281
282  return 0;
283}
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