1 /* -*- mode: C++; indent-tabs-mode: nil; -*-
3 * This file is a part of LEMON, a generic C++ optimization library.
5 * Copyright (C) 2003-2010
6 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 * (Egervary Research Group on Combinatorial Optimization, EGRES).
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.
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
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>
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>
33 #include "test_tools.h"
35 using namespace lemon;
37 // // Tests checkMetricCost() function
38 // void metricCostTest() {
39 // GRAPH_TYPEDEFS(FullGraph);
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()");
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));
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()");
63 // Checks tour validity
64 template <typename Container>
65 bool checkTour(const FullGraph &gr, const Container &p) {
66 FullGraph::NodeMap<bool> used(gr, false);
69 for (typename Container::const_iterator it = p.begin(); it != p.end(); ++it) {
70 FullGraph::Node node = *it;
71 if (used[node]) return false;
76 return (node_cnt == gr.nodeNum());
79 // Checks tour validity
80 bool checkTourPath(const FullGraph &gr, const Path<FullGraph> &p) {
81 FullGraph::NodeMap<bool> used(gr, false);
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;
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;
95 template <typename CostMap>
96 bool checkCost(const FullGraph &gr, const std::vector<FullGraph::Node> &p,
97 const CostMap &cost, typename CostMap::Value total)
99 typedef typename CostMap::Value Cost;
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())];
107 return !Tolerance<Cost>().different(s, total);
111 template <typename CostMap>
112 bool checkCost(const FullGraph &, const Path<FullGraph> &p,
113 const CostMap &cost, typename CostMap::Value total)
115 typedef typename CostMap::Value Cost;
118 for (int i = 0; i < p.length(); ++i)
121 return !Tolerance<Cost>().different(s, total);
124 // Tests a TSP algorithm on small graphs
125 template <typename TSP>
126 void tspTestSmall(const std::string &alg_name) {
127 GRAPH_TYPEDEFS(FullGraph);
129 for (int n = 0; n <= 5; ++n) {
132 int esize = n <= 1 ? 0 : n;
134 TSP alg(g, constMap<Edge, int>(1));
136 check(alg.run() == esize, alg_name + ": Wrong total cost");
137 check(alg.tourCost() == esize, alg_name + ": Wrong total cost");
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");
153 SimplePath<FullGraph> 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");
162 // Tests a TSP algorithm on random graphs
163 template <typename TSP>
164 void tspTestRandom(const std::string &alg_name) {
165 GRAPH_TYPEDEFS(FullGraph);
168 FullGraph::NodeMap<dim2::Point<double> > pos(g);
169 DoubleEdgeMap cost(g);
172 Opt2Tsp<DoubleEdgeMap > opt2(g, cost);
174 for (int i = 1; i <= 3; i++) {
175 for (NodeIt u(g); u != INVALID; ++u) {
176 pos[u] = dim2::Point<double>(rnd(), rnd());
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();
185 check(alg.run() > 0, alg_name + ": Wrong total cost");
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");
193 SimplePath<FullGraph> path;
195 check(checkTourPath(g, path), alg_name + ": Wrong tour");
196 check(checkCost(g, path, cost, alg.tourCost()),
197 alg_name + ": Wrong tour cost");
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");
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");
215 // Algorithm class for Nearest Insertion
216 template <typename CM>
217 class NearestInsertionTsp : public InsertionTsp<CM> {
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);
226 // Algorithm class for Farthest Insertion
227 template <typename CM>
228 class FarthestInsertionTsp : public InsertionTsp<CM> {
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);
237 // Algorithm class for Cheapest Insertion
238 template <typename CM>
239 class CheapestInsertionTsp : public InsertionTsp<CM> {
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);
248 // Algorithm class for Random Insertion
249 template <typename CM>
250 class RandomInsertionTsp : public InsertionTsp<CM> {
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);
260 GRAPH_TYPEDEFS(FullGraph);
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");
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");