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) 2003-2011 |
---|
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/concepts/digraph.h> |
---|
25 | #include <lemon/concepts/maps.h> |
---|
26 | #include <lemon/lgf_reader.h> |
---|
27 | #include <lemon/elevator.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 | "5\n" |
---|
40 | "6\n" |
---|
41 | "7\n" |
---|
42 | "8\n" |
---|
43 | "9\n" |
---|
44 | "@arcs\n" |
---|
45 | " label capacity\n" |
---|
46 | "0 1 0 20\n" |
---|
47 | "0 2 1 0\n" |
---|
48 | "1 1 2 3\n" |
---|
49 | "1 2 3 8\n" |
---|
50 | "1 3 4 8\n" |
---|
51 | "2 5 5 5\n" |
---|
52 | "3 2 6 5\n" |
---|
53 | "3 5 7 5\n" |
---|
54 | "3 6 8 5\n" |
---|
55 | "4 3 9 3\n" |
---|
56 | "5 7 10 3\n" |
---|
57 | "5 6 11 10\n" |
---|
58 | "5 8 12 10\n" |
---|
59 | "6 8 13 8\n" |
---|
60 | "8 9 14 20\n" |
---|
61 | "8 1 15 5\n" |
---|
62 | "9 5 16 5\n" |
---|
63 | "@attributes\n" |
---|
64 | "source 1\n" |
---|
65 | "target 8\n"; |
---|
66 | |
---|
67 | void checkPreflowCompile() |
---|
68 | { |
---|
69 | typedef int VType; |
---|
70 | typedef concepts::Digraph Digraph; |
---|
71 | |
---|
72 | typedef Digraph::Node Node; |
---|
73 | typedef Digraph::Arc Arc; |
---|
74 | typedef concepts::ReadMap<Arc,VType> CapMap; |
---|
75 | typedef concepts::ReadWriteMap<Arc,VType> FlowMap; |
---|
76 | typedef concepts::WriteMap<Node,bool> CutMap; |
---|
77 | |
---|
78 | typedef Elevator<Digraph, Digraph::Node> Elev; |
---|
79 | typedef LinkedElevator<Digraph, Digraph::Node> LinkedElev; |
---|
80 | |
---|
81 | Digraph g; |
---|
82 | Node n; |
---|
83 | Arc e; |
---|
84 | CapMap cap; |
---|
85 | FlowMap flow; |
---|
86 | CutMap cut; |
---|
87 | VType v; |
---|
88 | bool b; |
---|
89 | ::lemon::ignore_unused_variable_warning(v,b); |
---|
90 | |
---|
91 | typedef Preflow<Digraph, CapMap> |
---|
92 | ::SetFlowMap<FlowMap> |
---|
93 | ::SetElevator<Elev> |
---|
94 | ::SetStandardElevator<LinkedElev> |
---|
95 | ::Create PreflowType; |
---|
96 | PreflowType preflow_test(g, cap, n, n); |
---|
97 | const PreflowType& const_preflow_test = preflow_test; |
---|
98 | |
---|
99 | const PreflowType::Elevator& elev = const_preflow_test.elevator(); |
---|
100 | preflow_test.elevator(const_cast<PreflowType::Elevator&>(elev)); |
---|
101 | PreflowType::Tolerance tol = const_preflow_test.tolerance(); |
---|
102 | preflow_test.tolerance(tol); |
---|
103 | |
---|
104 | preflow_test |
---|
105 | .capacityMap(cap) |
---|
106 | .flowMap(flow) |
---|
107 | .source(n) |
---|
108 | .target(n); |
---|
109 | |
---|
110 | preflow_test.init(); |
---|
111 | preflow_test.init(cap); |
---|
112 | preflow_test.startFirstPhase(); |
---|
113 | preflow_test.startSecondPhase(); |
---|
114 | preflow_test.run(); |
---|
115 | preflow_test.runMinCut(); |
---|
116 | |
---|
117 | v = const_preflow_test.flowValue(); |
---|
118 | v = const_preflow_test.flow(e); |
---|
119 | const FlowMap& fm = const_preflow_test.flowMap(); |
---|
120 | b = const_preflow_test.minCut(n); |
---|
121 | const_preflow_test.minCutMap(cut); |
---|
122 | |
---|
123 | ::lemon::ignore_unused_variable_warning(fm); |
---|
124 | } |
---|
125 | |
---|
126 | int cutValue (const SmartDigraph& g, |
---|
127 | const SmartDigraph::NodeMap<bool>& cut, |
---|
128 | const SmartDigraph::ArcMap<int>& cap) { |
---|
129 | |
---|
130 | int c=0; |
---|
131 | for(SmartDigraph::ArcIt e(g); e!=INVALID; ++e) { |
---|
132 | if (cut[g.source(e)] && !cut[g.target(e)]) c+=cap[e]; |
---|
133 | } |
---|
134 | return c; |
---|
135 | } |
---|
136 | |
---|
137 | bool checkFlow(const SmartDigraph& g, |
---|
138 | const SmartDigraph::ArcMap<int>& flow, |
---|
139 | const SmartDigraph::ArcMap<int>& cap, |
---|
140 | SmartDigraph::Node s, SmartDigraph::Node t) { |
---|
141 | |
---|
142 | for (SmartDigraph::ArcIt e(g); e != INVALID; ++e) { |
---|
143 | if (flow[e] < 0 || flow[e] > cap[e]) return false; |
---|
144 | } |
---|
145 | |
---|
146 | for (SmartDigraph::NodeIt n(g); n != INVALID; ++n) { |
---|
147 | if (n == s || n == t) continue; |
---|
148 | int sum = 0; |
---|
149 | for (SmartDigraph::OutArcIt e(g, n); e != INVALID; ++e) { |
---|
150 | sum += flow[e]; |
---|
151 | } |
---|
152 | for (SmartDigraph::InArcIt e(g, n); e != INVALID; ++e) { |
---|
153 | sum -= flow[e]; |
---|
154 | } |
---|
155 | if (sum != 0) return false; |
---|
156 | } |
---|
157 | return true; |
---|
158 | } |
---|
159 | |
---|
160 | void initFlowTest() |
---|
161 | { |
---|
162 | DIGRAPH_TYPEDEFS(SmartDigraph); |
---|
163 | |
---|
164 | SmartDigraph g; |
---|
165 | SmartDigraph::ArcMap<int> cap(g),iflow(g); |
---|
166 | Node s=g.addNode(); Node t=g.addNode(); |
---|
167 | Node n1=g.addNode(); Node n2=g.addNode(); |
---|
168 | Arc a; |
---|
169 | a=g.addArc(s,n1); cap[a]=20; iflow[a]=20; |
---|
170 | a=g.addArc(n1,n2); cap[a]=10; iflow[a]=0; |
---|
171 | a=g.addArc(n2,t); cap[a]=20; iflow[a]=0; |
---|
172 | |
---|
173 | Preflow<SmartDigraph> pre(g,cap,s,t); |
---|
174 | pre.init(iflow); |
---|
175 | pre.startFirstPhase(); |
---|
176 | check(pre.flowValue() == 10, "The incorrect max flow value."); |
---|
177 | check(pre.minCut(s), "Wrong min cut (Node s)."); |
---|
178 | check(pre.minCut(n1), "Wrong min cut (Node n1)."); |
---|
179 | check(!pre.minCut(n2), "Wrong min cut (Node n2)."); |
---|
180 | check(!pre.minCut(t), "Wrong min cut (Node t)."); |
---|
181 | } |
---|
182 | |
---|
183 | |
---|
184 | int main() { |
---|
185 | |
---|
186 | typedef SmartDigraph Digraph; |
---|
187 | |
---|
188 | typedef Digraph::Node Node; |
---|
189 | typedef Digraph::NodeIt NodeIt; |
---|
190 | typedef Digraph::ArcIt ArcIt; |
---|
191 | typedef Digraph::ArcMap<int> CapMap; |
---|
192 | typedef Digraph::ArcMap<int> FlowMap; |
---|
193 | typedef Digraph::NodeMap<bool> CutMap; |
---|
194 | |
---|
195 | typedef Preflow<Digraph, CapMap> PType; |
---|
196 | |
---|
197 | Digraph g; |
---|
198 | Node s, t; |
---|
199 | CapMap cap(g); |
---|
200 | std::istringstream input(test_lgf); |
---|
201 | DigraphReader<Digraph>(g,input). |
---|
202 | arcMap("capacity", cap). |
---|
203 | node("source",s). |
---|
204 | node("target",t). |
---|
205 | run(); |
---|
206 | |
---|
207 | PType preflow_test(g, cap, s, t); |
---|
208 | preflow_test.run(); |
---|
209 | |
---|
210 | check(checkFlow(g, preflow_test.flowMap(), cap, s, t), |
---|
211 | "The flow is not feasible."); |
---|
212 | |
---|
213 | CutMap min_cut(g); |
---|
214 | preflow_test.minCutMap(min_cut); |
---|
215 | int min_cut_value=cutValue(g,min_cut,cap); |
---|
216 | |
---|
217 | check(preflow_test.flowValue() == min_cut_value, |
---|
218 | "The max flow value is not equal to the three min cut values."); |
---|
219 | |
---|
220 | FlowMap flow(g); |
---|
221 | for(ArcIt e(g); e!=INVALID; ++e) flow[e] = preflow_test.flowMap()[e]; |
---|
222 | |
---|
223 | int flow_value=preflow_test.flowValue(); |
---|
224 | |
---|
225 | for(ArcIt e(g); e!=INVALID; ++e) cap[e]=2*cap[e]; |
---|
226 | preflow_test.init(flow); |
---|
227 | preflow_test.startFirstPhase(); |
---|
228 | |
---|
229 | CutMap min_cut1(g); |
---|
230 | preflow_test.minCutMap(min_cut1); |
---|
231 | min_cut_value=cutValue(g,min_cut1,cap); |
---|
232 | |
---|
233 | check(preflow_test.flowValue() == min_cut_value && |
---|
234 | min_cut_value == 2*flow_value, |
---|
235 | "The max flow value or the min cut value is wrong."); |
---|
236 | |
---|
237 | preflow_test.startSecondPhase(); |
---|
238 | |
---|
239 | check(checkFlow(g, preflow_test.flowMap(), cap, s, t), |
---|
240 | "The flow is not feasible."); |
---|
241 | |
---|
242 | CutMap min_cut2(g); |
---|
243 | preflow_test.minCutMap(min_cut2); |
---|
244 | min_cut_value=cutValue(g,min_cut2,cap); |
---|
245 | |
---|
246 | check(preflow_test.flowValue() == min_cut_value && |
---|
247 | min_cut_value == 2*flow_value, |
---|
248 | "The max flow value or the three min cut values were not doubled"); |
---|
249 | |
---|
250 | |
---|
251 | preflow_test.flowMap(flow); |
---|
252 | |
---|
253 | NodeIt tmp1(g,s); |
---|
254 | ++tmp1; |
---|
255 | if ( tmp1 != INVALID ) s=tmp1; |
---|
256 | |
---|
257 | NodeIt tmp2(g,t); |
---|
258 | ++tmp2; |
---|
259 | if ( tmp2 != INVALID ) t=tmp2; |
---|
260 | |
---|
261 | preflow_test.source(s); |
---|
262 | preflow_test.target(t); |
---|
263 | |
---|
264 | preflow_test.run(); |
---|
265 | |
---|
266 | CutMap min_cut3(g); |
---|
267 | preflow_test.minCutMap(min_cut3); |
---|
268 | min_cut_value=cutValue(g,min_cut3,cap); |
---|
269 | |
---|
270 | |
---|
271 | check(preflow_test.flowValue() == min_cut_value, |
---|
272 | "The max flow value or the three min cut values are incorrect."); |
---|
273 | |
---|
274 | initFlowTest(); |
---|
275 | |
---|
276 | return 0; |
---|
277 | } |
---|