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) 2003-2010 |
---|
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 "test_tools.h" |
---|
22 | #include <lemon/smart_graph.h> |
---|
23 | #include <lemon/preflow.h> |
---|
24 | #include <lemon/edmonds_karp.h> |
---|
25 | #include <lemon/concepts/digraph.h> |
---|
26 | #include <lemon/concepts/maps.h> |
---|
27 | #include <lemon/lgf_reader.h> |
---|
28 | #include <lemon/elevator.h> |
---|
29 | |
---|
30 | using namespace lemon; |
---|
31 | |
---|
32 | char test_lgf[] = |
---|
33 | "@nodes\n" |
---|
34 | "label\n" |
---|
35 | "0\n" |
---|
36 | "1\n" |
---|
37 | "2\n" |
---|
38 | "3\n" |
---|
39 | "4\n" |
---|
40 | "5\n" |
---|
41 | "6\n" |
---|
42 | "7\n" |
---|
43 | "8\n" |
---|
44 | "9\n" |
---|
45 | "@arcs\n" |
---|
46 | " label capacity\n" |
---|
47 | "0 1 0 20\n" |
---|
48 | "0 2 1 0\n" |
---|
49 | "1 1 2 3\n" |
---|
50 | "1 2 3 8\n" |
---|
51 | "1 3 4 8\n" |
---|
52 | "2 5 5 5\n" |
---|
53 | "3 2 6 5\n" |
---|
54 | "3 5 7 5\n" |
---|
55 | "3 6 8 5\n" |
---|
56 | "4 3 9 3\n" |
---|
57 | "5 7 10 3\n" |
---|
58 | "5 6 11 10\n" |
---|
59 | "5 8 12 10\n" |
---|
60 | "6 8 13 8\n" |
---|
61 | "8 9 14 20\n" |
---|
62 | "8 1 15 5\n" |
---|
63 | "9 5 16 5\n" |
---|
64 | "@attributes\n" |
---|
65 | "source 1\n" |
---|
66 | "target 8\n"; |
---|
67 | |
---|
68 | |
---|
69 | // Checks the general interface of a max flow algorithm |
---|
70 | template <typename GR, typename CAP> |
---|
71 | struct MaxFlowClassConcept |
---|
72 | { |
---|
73 | |
---|
74 | template <typename MF> |
---|
75 | struct Constraints { |
---|
76 | |
---|
77 | typedef typename GR::Node Node; |
---|
78 | typedef typename GR::Arc Arc; |
---|
79 | typedef typename CAP::Value Value; |
---|
80 | typedef concepts::ReadWriteMap<Arc, Value> FlowMap; |
---|
81 | typedef concepts::WriteMap<Node, bool> CutMap; |
---|
82 | |
---|
83 | GR g; |
---|
84 | Node n; |
---|
85 | Arc e; |
---|
86 | CAP cap; |
---|
87 | FlowMap flow; |
---|
88 | CutMap cut; |
---|
89 | Value v; |
---|
90 | bool b; |
---|
91 | |
---|
92 | void constraints() { |
---|
93 | checkConcept<concepts::Digraph, GR>(); |
---|
94 | |
---|
95 | const Constraints& me = *this; |
---|
96 | |
---|
97 | typedef typename MF |
---|
98 | ::template SetFlowMap<FlowMap> |
---|
99 | ::Create MaxFlowType; |
---|
100 | typedef typename MF::Create MaxFlowType2; |
---|
101 | MaxFlowType max_flow(me.g, me.cap, me.n, me.n); |
---|
102 | const MaxFlowType& const_max_flow = max_flow; |
---|
103 | |
---|
104 | max_flow |
---|
105 | .capacityMap(cap) |
---|
106 | .flowMap(flow) |
---|
107 | .source(n) |
---|
108 | .target(n); |
---|
109 | |
---|
110 | typename MaxFlowType::Tolerance tol = const_max_flow.tolerance(); |
---|
111 | max_flow.tolerance(tol); |
---|
112 | |
---|
113 | max_flow.init(); |
---|
114 | max_flow.init(cap); |
---|
115 | max_flow.run(); |
---|
116 | |
---|
117 | v = const_max_flow.flowValue(); |
---|
118 | v = const_max_flow.flow(e); |
---|
119 | const FlowMap& fm = const_max_flow.flowMap(); |
---|
120 | |
---|
121 | b = const_max_flow.minCut(n); |
---|
122 | const_max_flow.minCutMap(cut); |
---|
123 | |
---|
124 | ignore_unused_variable_warning(fm); |
---|
125 | } |
---|
126 | |
---|
127 | }; |
---|
128 | |
---|
129 | }; |
---|
130 | |
---|
131 | // Checks the specific parts of Preflow's interface |
---|
132 | void checkPreflowCompile() |
---|
133 | { |
---|
134 | typedef int Value; |
---|
135 | typedef concepts::Digraph Digraph; |
---|
136 | typedef concepts::ReadMap<Digraph::Arc, Value> CapMap; |
---|
137 | typedef Elevator<Digraph, Digraph::Node> Elev; |
---|
138 | typedef LinkedElevator<Digraph, Digraph::Node> LinkedElev; |
---|
139 | |
---|
140 | Digraph g; |
---|
141 | Digraph::Node n; |
---|
142 | CapMap cap; |
---|
143 | |
---|
144 | typedef Preflow<Digraph, CapMap> |
---|
145 | ::SetElevator<Elev> |
---|
146 | ::SetStandardElevator<LinkedElev> |
---|
147 | ::Create PreflowType; |
---|
148 | PreflowType preflow_test(g, cap, n, n); |
---|
149 | const PreflowType& const_preflow_test = preflow_test; |
---|
150 | |
---|
151 | const PreflowType::Elevator& elev = const_preflow_test.elevator(); |
---|
152 | preflow_test.elevator(const_cast<PreflowType::Elevator&>(elev)); |
---|
153 | |
---|
154 | bool b = preflow_test.init(cap); |
---|
155 | preflow_test.startFirstPhase(); |
---|
156 | preflow_test.startSecondPhase(); |
---|
157 | preflow_test.runMinCut(); |
---|
158 | |
---|
159 | ignore_unused_variable_warning(b); |
---|
160 | } |
---|
161 | |
---|
162 | // Checks the specific parts of EdmondsKarp's interface |
---|
163 | void checkEdmondsKarpCompile() |
---|
164 | { |
---|
165 | typedef int Value; |
---|
166 | typedef concepts::Digraph Digraph; |
---|
167 | typedef concepts::ReadMap<Digraph::Arc, Value> CapMap; |
---|
168 | typedef Elevator<Digraph, Digraph::Node> Elev; |
---|
169 | typedef LinkedElevator<Digraph, Digraph::Node> LinkedElev; |
---|
170 | |
---|
171 | Digraph g; |
---|
172 | Digraph::Node n; |
---|
173 | CapMap cap; |
---|
174 | |
---|
175 | EdmondsKarp<Digraph, CapMap> ek_test(g, cap, n, n); |
---|
176 | |
---|
177 | ek_test.init(cap); |
---|
178 | bool b = ek_test.checkedInit(cap); |
---|
179 | b = ek_test.augment(); |
---|
180 | ek_test.start(); |
---|
181 | |
---|
182 | ignore_unused_variable_warning(b); |
---|
183 | } |
---|
184 | |
---|
185 | |
---|
186 | template <typename T> |
---|
187 | T cutValue (const SmartDigraph& g, |
---|
188 | const SmartDigraph::NodeMap<bool>& cut, |
---|
189 | const SmartDigraph::ArcMap<T>& cap) { |
---|
190 | |
---|
191 | T c=0; |
---|
192 | for(SmartDigraph::ArcIt e(g); e!=INVALID; ++e) { |
---|
193 | if (cut[g.source(e)] && !cut[g.target(e)]) c+=cap[e]; |
---|
194 | } |
---|
195 | return c; |
---|
196 | } |
---|
197 | |
---|
198 | template <typename T> |
---|
199 | bool checkFlow(const SmartDigraph& g, |
---|
200 | const SmartDigraph::ArcMap<T>& flow, |
---|
201 | const SmartDigraph::ArcMap<T>& cap, |
---|
202 | SmartDigraph::Node s, SmartDigraph::Node t) { |
---|
203 | |
---|
204 | for (SmartDigraph::ArcIt e(g); e != INVALID; ++e) { |
---|
205 | if (flow[e] < 0 || flow[e] > cap[e]) return false; |
---|
206 | } |
---|
207 | |
---|
208 | for (SmartDigraph::NodeIt n(g); n != INVALID; ++n) { |
---|
209 | if (n == s || n == t) continue; |
---|
210 | T sum = 0; |
---|
211 | for (SmartDigraph::OutArcIt e(g, n); e != INVALID; ++e) { |
---|
212 | sum += flow[e]; |
---|
213 | } |
---|
214 | for (SmartDigraph::InArcIt e(g, n); e != INVALID; ++e) { |
---|
215 | sum -= flow[e]; |
---|
216 | } |
---|
217 | if (sum != 0) return false; |
---|
218 | } |
---|
219 | return true; |
---|
220 | } |
---|
221 | |
---|
222 | void initFlowTest() |
---|
223 | { |
---|
224 | DIGRAPH_TYPEDEFS(SmartDigraph); |
---|
225 | |
---|
226 | SmartDigraph g; |
---|
227 | SmartDigraph::ArcMap<int> cap(g),iflow(g); |
---|
228 | Node s=g.addNode(); Node t=g.addNode(); |
---|
229 | Node n1=g.addNode(); Node n2=g.addNode(); |
---|
230 | Arc a; |
---|
231 | a=g.addArc(s,n1); cap[a]=20; iflow[a]=20; |
---|
232 | a=g.addArc(n1,n2); cap[a]=10; iflow[a]=0; |
---|
233 | a=g.addArc(n2,t); cap[a]=20; iflow[a]=0; |
---|
234 | |
---|
235 | Preflow<SmartDigraph> pre(g,cap,s,t); |
---|
236 | pre.init(iflow); |
---|
237 | pre.startFirstPhase(); |
---|
238 | check(pre.flowValue() == 10, "The incorrect max flow value."); |
---|
239 | check(pre.minCut(s), "Wrong min cut (Node s)."); |
---|
240 | check(pre.minCut(n1), "Wrong min cut (Node n1)."); |
---|
241 | check(!pre.minCut(n2), "Wrong min cut (Node n2)."); |
---|
242 | check(!pre.minCut(t), "Wrong min cut (Node t)."); |
---|
243 | } |
---|
244 | |
---|
245 | template <typename MF, typename SF> |
---|
246 | void checkMaxFlowAlg() { |
---|
247 | typedef SmartDigraph Digraph; |
---|
248 | DIGRAPH_TYPEDEFS(Digraph); |
---|
249 | |
---|
250 | typedef typename MF::Value Value; |
---|
251 | typedef Digraph::ArcMap<Value> CapMap; |
---|
252 | typedef CapMap FlowMap; |
---|
253 | typedef BoolNodeMap CutMap; |
---|
254 | |
---|
255 | Digraph g; |
---|
256 | Node s, t; |
---|
257 | CapMap cap(g); |
---|
258 | std::istringstream input(test_lgf); |
---|
259 | DigraphReader<Digraph>(g,input) |
---|
260 | .arcMap("capacity", cap) |
---|
261 | .node("source",s) |
---|
262 | .node("target",t) |
---|
263 | .run(); |
---|
264 | |
---|
265 | MF max_flow(g, cap, s, t); |
---|
266 | max_flow.run(); |
---|
267 | |
---|
268 | check(checkFlow(g, max_flow.flowMap(), cap, s, t), |
---|
269 | "The flow is not feasible."); |
---|
270 | |
---|
271 | CutMap min_cut(g); |
---|
272 | max_flow.minCutMap(min_cut); |
---|
273 | Value min_cut_value = cutValue(g, min_cut, cap); |
---|
274 | |
---|
275 | check(max_flow.flowValue() == min_cut_value, |
---|
276 | "The max flow value is not equal to the min cut value."); |
---|
277 | |
---|
278 | FlowMap flow(g); |
---|
279 | for (ArcIt e(g); e != INVALID; ++e) flow[e] = max_flow.flowMap()[e]; |
---|
280 | |
---|
281 | Value flow_value = max_flow.flowValue(); |
---|
282 | |
---|
283 | for (ArcIt e(g); e != INVALID; ++e) cap[e] = 2 * cap[e]; |
---|
284 | max_flow.init(flow); |
---|
285 | |
---|
286 | SF::startFirstPhase(max_flow); // start first phase of the algorithm |
---|
287 | |
---|
288 | CutMap min_cut1(g); |
---|
289 | max_flow.minCutMap(min_cut1); |
---|
290 | min_cut_value = cutValue(g, min_cut1, cap); |
---|
291 | |
---|
292 | check(max_flow.flowValue() == min_cut_value && |
---|
293 | min_cut_value == 2 * flow_value, |
---|
294 | "The max flow value or the min cut value is wrong."); |
---|
295 | |
---|
296 | SF::startSecondPhase(max_flow); // start second phase of the algorithm |
---|
297 | |
---|
298 | check(checkFlow(g, max_flow.flowMap(), cap, s, t), |
---|
299 | "The flow is not feasible."); |
---|
300 | |
---|
301 | CutMap min_cut2(g); |
---|
302 | max_flow.minCutMap(min_cut2); |
---|
303 | min_cut_value = cutValue(g, min_cut2, cap); |
---|
304 | |
---|
305 | check(max_flow.flowValue() == min_cut_value && |
---|
306 | min_cut_value == 2 * flow_value, |
---|
307 | "The max flow value or the min cut value was not doubled"); |
---|
308 | |
---|
309 | |
---|
310 | max_flow.flowMap(flow); |
---|
311 | |
---|
312 | NodeIt tmp1(g, s); |
---|
313 | ++tmp1; |
---|
314 | if (tmp1 != INVALID) s = tmp1; |
---|
315 | |
---|
316 | NodeIt tmp2(g, t); |
---|
317 | ++tmp2; |
---|
318 | if (tmp2 != INVALID) t = tmp2; |
---|
319 | |
---|
320 | max_flow.source(s); |
---|
321 | max_flow.target(t); |
---|
322 | |
---|
323 | max_flow.run(); |
---|
324 | |
---|
325 | CutMap min_cut3(g); |
---|
326 | max_flow.minCutMap(min_cut3); |
---|
327 | min_cut_value=cutValue(g, min_cut3, cap); |
---|
328 | |
---|
329 | check(max_flow.flowValue() == min_cut_value, |
---|
330 | "The max flow value or the min cut value is wrong."); |
---|
331 | } |
---|
332 | |
---|
333 | // Struct for calling start functions of a general max flow algorithm |
---|
334 | template <typename MF> |
---|
335 | struct GeneralStartFunctions { |
---|
336 | |
---|
337 | static void startFirstPhase(MF& mf) { |
---|
338 | mf.start(); |
---|
339 | } |
---|
340 | |
---|
341 | static void startSecondPhase(MF& mf) { |
---|
342 | ignore_unused_variable_warning(mf); |
---|
343 | } |
---|
344 | |
---|
345 | }; |
---|
346 | |
---|
347 | // Struct for calling start functions of Preflow |
---|
348 | template <typename MF> |
---|
349 | struct PreflowStartFunctions { |
---|
350 | |
---|
351 | static void startFirstPhase(MF& mf) { |
---|
352 | mf.startFirstPhase(); |
---|
353 | } |
---|
354 | |
---|
355 | static void startSecondPhase(MF& mf) { |
---|
356 | mf.startSecondPhase(); |
---|
357 | } |
---|
358 | |
---|
359 | }; |
---|
360 | |
---|
361 | int main() { |
---|
362 | |
---|
363 | typedef concepts::Digraph GR; |
---|
364 | typedef concepts::ReadMap<GR::Arc, int> CM1; |
---|
365 | typedef concepts::ReadMap<GR::Arc, double> CM2; |
---|
366 | |
---|
367 | // Check the interface of Preflow |
---|
368 | checkConcept< MaxFlowClassConcept<GR, CM1>, |
---|
369 | Preflow<GR, CM1> >(); |
---|
370 | checkConcept< MaxFlowClassConcept<GR, CM2>, |
---|
371 | Preflow<GR, CM2> >(); |
---|
372 | |
---|
373 | // Check the interface of EdmondsKarp |
---|
374 | checkConcept< MaxFlowClassConcept<GR, CM1>, |
---|
375 | EdmondsKarp<GR, CM1> >(); |
---|
376 | checkConcept< MaxFlowClassConcept<GR, CM2>, |
---|
377 | EdmondsKarp<GR, CM2> >(); |
---|
378 | |
---|
379 | // Check Preflow |
---|
380 | typedef Preflow<SmartDigraph, SmartDigraph::ArcMap<int> > PType1; |
---|
381 | typedef Preflow<SmartDigraph, SmartDigraph::ArcMap<float> > PType2; |
---|
382 | checkMaxFlowAlg<PType1, PreflowStartFunctions<PType1> >(); |
---|
383 | checkMaxFlowAlg<PType2, PreflowStartFunctions<PType2> >(); |
---|
384 | initFlowTest(); |
---|
385 | |
---|
386 | // Check EdmondsKarp |
---|
387 | typedef EdmondsKarp<SmartDigraph, SmartDigraph::ArcMap<int> > EKType1; |
---|
388 | typedef EdmondsKarp<SmartDigraph, SmartDigraph::ArcMap<float> > EKType2; |
---|
389 | checkMaxFlowAlg<EKType1, GeneralStartFunctions<EKType1> >(); |
---|
390 | checkMaxFlowAlg<EKType2, GeneralStartFunctions<EKType2> >(); |
---|
391 | |
---|
392 | initFlowTest(); |
---|
393 | |
---|
394 | return 0; |
---|
395 | } |
---|