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 <lemon/concepts/digraph.h> |
---|
20 | #include <lemon/smart_graph.h> |
---|
21 | #include <lemon/list_graph.h> |
---|
22 | #include <lemon/lgf_reader.h> |
---|
23 | #include <lemon/bellman_ford.h> |
---|
24 | #include <lemon/path.h> |
---|
25 | |
---|
26 | #include "graph_test.h" |
---|
27 | #include "test_tools.h" |
---|
28 | |
---|
29 | using namespace lemon; |
---|
30 | |
---|
31 | char test_lgf[] = |
---|
32 | "@nodes\n" |
---|
33 | "label\n" |
---|
34 | "0\n" |
---|
35 | "1\n" |
---|
36 | "2\n" |
---|
37 | "3\n" |
---|
38 | "4\n" |
---|
39 | "@arcs\n" |
---|
40 | " length\n" |
---|
41 | "0 1 3\n" |
---|
42 | "1 2 -3\n" |
---|
43 | "1 2 -5\n" |
---|
44 | "1 3 -2\n" |
---|
45 | "0 2 -1\n" |
---|
46 | "1 2 -4\n" |
---|
47 | "0 3 2\n" |
---|
48 | "4 2 -5\n" |
---|
49 | "2 3 1\n" |
---|
50 | "@attributes\n" |
---|
51 | "source 0\n" |
---|
52 | "target 3\n"; |
---|
53 | |
---|
54 | |
---|
55 | void checkBellmanFordCompile() |
---|
56 | { |
---|
57 | typedef int Value; |
---|
58 | typedef concepts::Digraph Digraph; |
---|
59 | typedef concepts::ReadMap<Digraph::Arc,Value> LengthMap; |
---|
60 | typedef BellmanFord<Digraph, LengthMap> BF; |
---|
61 | typedef Digraph::Node Node; |
---|
62 | typedef Digraph::Arc Arc; |
---|
63 | |
---|
64 | Digraph gr; |
---|
65 | Node s, t, n; |
---|
66 | Arc e; |
---|
67 | Value l; |
---|
68 | ::lemon::ignore_unused_variable_warning(l); |
---|
69 | int k=3; |
---|
70 | bool b; |
---|
71 | ::lemon::ignore_unused_variable_warning(b); |
---|
72 | BF::DistMap d(gr); |
---|
73 | BF::PredMap p(gr); |
---|
74 | LengthMap length; |
---|
75 | concepts::Path<Digraph> pp; |
---|
76 | |
---|
77 | { |
---|
78 | BF bf_test(gr,length); |
---|
79 | const BF& const_bf_test = bf_test; |
---|
80 | |
---|
81 | bf_test.run(s); |
---|
82 | bf_test.run(s,k); |
---|
83 | |
---|
84 | bf_test.init(); |
---|
85 | bf_test.addSource(s); |
---|
86 | bf_test.addSource(s, 1); |
---|
87 | b = bf_test.processNextRound(); |
---|
88 | b = bf_test.processNextWeakRound(); |
---|
89 | |
---|
90 | bf_test.start(); |
---|
91 | bf_test.checkedStart(); |
---|
92 | bf_test.limitedStart(k); |
---|
93 | |
---|
94 | l = const_bf_test.dist(t); |
---|
95 | e = const_bf_test.predArc(t); |
---|
96 | s = const_bf_test.predNode(t); |
---|
97 | b = const_bf_test.reached(t); |
---|
98 | d = const_bf_test.distMap(); |
---|
99 | p = const_bf_test.predMap(); |
---|
100 | pp = const_bf_test.path(t); |
---|
101 | pp = const_bf_test.negativeCycle(); |
---|
102 | |
---|
103 | for (BF::ActiveIt it(const_bf_test); it != INVALID; ++it) {} |
---|
104 | } |
---|
105 | { |
---|
106 | BF::SetPredMap<concepts::ReadWriteMap<Node,Arc> > |
---|
107 | ::SetDistMap<concepts::ReadWriteMap<Node,Value> > |
---|
108 | ::SetOperationTraits<BellmanFordDefaultOperationTraits<Value> > |
---|
109 | ::Create bf_test(gr,length); |
---|
110 | |
---|
111 | LengthMap length_map; |
---|
112 | concepts::ReadWriteMap<Node,Arc> pred_map; |
---|
113 | concepts::ReadWriteMap<Node,Value> dist_map; |
---|
114 | |
---|
115 | bf_test |
---|
116 | .lengthMap(length_map) |
---|
117 | .predMap(pred_map) |
---|
118 | .distMap(dist_map); |
---|
119 | |
---|
120 | bf_test.run(s); |
---|
121 | bf_test.run(s,k); |
---|
122 | |
---|
123 | bf_test.init(); |
---|
124 | bf_test.addSource(s); |
---|
125 | bf_test.addSource(s, 1); |
---|
126 | b = bf_test.processNextRound(); |
---|
127 | b = bf_test.processNextWeakRound(); |
---|
128 | |
---|
129 | bf_test.start(); |
---|
130 | bf_test.checkedStart(); |
---|
131 | bf_test.limitedStart(k); |
---|
132 | |
---|
133 | l = bf_test.dist(t); |
---|
134 | e = bf_test.predArc(t); |
---|
135 | s = bf_test.predNode(t); |
---|
136 | b = bf_test.reached(t); |
---|
137 | pp = bf_test.path(t); |
---|
138 | pp = bf_test.negativeCycle(); |
---|
139 | } |
---|
140 | } |
---|
141 | |
---|
142 | void checkBellmanFordFunctionCompile() |
---|
143 | { |
---|
144 | typedef int Value; |
---|
145 | typedef concepts::Digraph Digraph; |
---|
146 | typedef Digraph::Arc Arc; |
---|
147 | typedef Digraph::Node Node; |
---|
148 | typedef concepts::ReadMap<Digraph::Arc,Value> LengthMap; |
---|
149 | |
---|
150 | Digraph g; |
---|
151 | bool b; |
---|
152 | ::lemon::ignore_unused_variable_warning(b); |
---|
153 | |
---|
154 | bellmanFord(g,LengthMap()).run(Node()); |
---|
155 | b = bellmanFord(g,LengthMap()).run(Node(),Node()); |
---|
156 | bellmanFord(g,LengthMap()) |
---|
157 | .predMap(concepts::ReadWriteMap<Node,Arc>()) |
---|
158 | .distMap(concepts::ReadWriteMap<Node,Value>()) |
---|
159 | .run(Node()); |
---|
160 | b=bellmanFord(g,LengthMap()) |
---|
161 | .predMap(concepts::ReadWriteMap<Node,Arc>()) |
---|
162 | .distMap(concepts::ReadWriteMap<Node,Value>()) |
---|
163 | .path(concepts::Path<Digraph>()) |
---|
164 | .dist(Value()) |
---|
165 | .run(Node(),Node()); |
---|
166 | } |
---|
167 | |
---|
168 | |
---|
169 | template <typename Digraph, typename Value> |
---|
170 | void checkBellmanFord() { |
---|
171 | TEMPLATE_DIGRAPH_TYPEDEFS(Digraph); |
---|
172 | typedef typename Digraph::template ArcMap<Value> LengthMap; |
---|
173 | |
---|
174 | Digraph gr; |
---|
175 | Node s, t; |
---|
176 | LengthMap length(gr); |
---|
177 | |
---|
178 | std::istringstream input(test_lgf); |
---|
179 | digraphReader(gr, input). |
---|
180 | arcMap("length", length). |
---|
181 | node("source", s). |
---|
182 | node("target", t). |
---|
183 | run(); |
---|
184 | |
---|
185 | BellmanFord<Digraph, LengthMap> |
---|
186 | bf(gr, length); |
---|
187 | bf.run(s); |
---|
188 | Path<Digraph> p = bf.path(t); |
---|
189 | |
---|
190 | check(bf.reached(t) && bf.dist(t) == -1, "Bellman-Ford found a wrong path."); |
---|
191 | check(p.length() == 3, "path() found a wrong path."); |
---|
192 | check(checkPath(gr, p), "path() found a wrong path."); |
---|
193 | check(pathSource(gr, p) == s, "path() found a wrong path."); |
---|
194 | check(pathTarget(gr, p) == t, "path() found a wrong path."); |
---|
195 | |
---|
196 | ListPath<Digraph> path; |
---|
197 | Value dist = 0; |
---|
198 | bool reached = bellmanFord(gr,length).path(path).dist(dist).run(s,t); |
---|
199 | |
---|
200 | check(reached && dist == -1, "Bellman-Ford found a wrong path."); |
---|
201 | check(path.length() == 3, "path() found a wrong path."); |
---|
202 | check(checkPath(gr, path), "path() found a wrong path."); |
---|
203 | check(pathSource(gr, path) == s, "path() found a wrong path."); |
---|
204 | check(pathTarget(gr, path) == t, "path() found a wrong path."); |
---|
205 | |
---|
206 | for(ArcIt e(gr); e!=INVALID; ++e) { |
---|
207 | Node u=gr.source(e); |
---|
208 | Node v=gr.target(e); |
---|
209 | check(!bf.reached(u) || (bf.dist(v) - bf.dist(u) <= length[e]), |
---|
210 | "Wrong output. dist(target)-dist(source)-arc_length=" << |
---|
211 | bf.dist(v) - bf.dist(u) - length[e]); |
---|
212 | } |
---|
213 | |
---|
214 | for(NodeIt v(gr); v!=INVALID; ++v) { |
---|
215 | if (bf.reached(v)) { |
---|
216 | check(v==s || bf.predArc(v)!=INVALID, "Wrong tree."); |
---|
217 | if (bf.predArc(v)!=INVALID ) { |
---|
218 | Arc e=bf.predArc(v); |
---|
219 | Node u=gr.source(e); |
---|
220 | check(u==bf.predNode(v),"Wrong tree."); |
---|
221 | check(bf.dist(v) - bf.dist(u) == length[e], |
---|
222 | "Wrong distance! Difference: " << |
---|
223 | bf.dist(v) - bf.dist(u) - length[e]); |
---|
224 | } |
---|
225 | } |
---|
226 | } |
---|
227 | } |
---|
228 | |
---|
229 | void checkBellmanFordNegativeCycle() { |
---|
230 | DIGRAPH_TYPEDEFS(SmartDigraph); |
---|
231 | |
---|
232 | SmartDigraph gr; |
---|
233 | IntArcMap length(gr); |
---|
234 | |
---|
235 | Node n1 = gr.addNode(); |
---|
236 | Node n2 = gr.addNode(); |
---|
237 | Node n3 = gr.addNode(); |
---|
238 | Node n4 = gr.addNode(); |
---|
239 | |
---|
240 | Arc a1 = gr.addArc(n1, n2); |
---|
241 | Arc a2 = gr.addArc(n2, n2); |
---|
242 | |
---|
243 | length[a1] = 2; |
---|
244 | length[a2] = -1; |
---|
245 | |
---|
246 | { |
---|
247 | BellmanFord<SmartDigraph, IntArcMap> bf(gr, length); |
---|
248 | bf.run(n1); |
---|
249 | StaticPath<SmartDigraph> p = bf.negativeCycle(); |
---|
250 | check(p.length() == 1 && p.front() == p.back() && p.front() == a2, |
---|
251 | "Wrong negative cycle."); |
---|
252 | } |
---|
253 | |
---|
254 | length[a2] = 0; |
---|
255 | |
---|
256 | { |
---|
257 | BellmanFord<SmartDigraph, IntArcMap> bf(gr, length); |
---|
258 | bf.run(n1); |
---|
259 | check(bf.negativeCycle().empty(), |
---|
260 | "Negative cycle should not be found."); |
---|
261 | } |
---|
262 | |
---|
263 | length[gr.addArc(n1, n3)] = 5; |
---|
264 | length[gr.addArc(n4, n3)] = 1; |
---|
265 | length[gr.addArc(n2, n4)] = 2; |
---|
266 | length[gr.addArc(n3, n2)] = -4; |
---|
267 | |
---|
268 | { |
---|
269 | BellmanFord<SmartDigraph, IntArcMap> bf(gr, length); |
---|
270 | bf.init(); |
---|
271 | bf.addSource(n1); |
---|
272 | for (int i = 0; i < 4; ++i) { |
---|
273 | check(bf.negativeCycle().empty(), |
---|
274 | "Negative cycle should not be found."); |
---|
275 | bf.processNextRound(); |
---|
276 | } |
---|
277 | StaticPath<SmartDigraph> p = bf.negativeCycle(); |
---|
278 | check(p.length() == 3, "Wrong negative cycle."); |
---|
279 | check(length[p.nth(0)] + length[p.nth(1)] + length[p.nth(2)] == -1, |
---|
280 | "Wrong negative cycle."); |
---|
281 | } |
---|
282 | } |
---|
283 | |
---|
284 | int main() { |
---|
285 | checkBellmanFord<ListDigraph, int>(); |
---|
286 | checkBellmanFord<SmartDigraph, double>(); |
---|
287 | checkBellmanFordNegativeCycle(); |
---|
288 | return 0; |
---|
289 | } |
---|