COIN-OR::LEMON - Graph Library

source: lemon/test/suurballe_test.cc @ 1172:c18ed26f016c

1.1
Last change on this file since 1172:c18ed26f016c was 1172:c18ed26f016c, checked in by Alpar Juttner <alpar@…>, 7 years ago

Merge bugfix #453 to branch 1.1

File size: 6.4 KB
Line 
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 <lemon/list_graph.h>
22#include <lemon/lgf_reader.h>
23#include <lemon/path.h>
24#include <lemon/suurballe.h>
25#include <lemon/concepts/digraph.h>
26
27#include "test_tools.h"
28
29using namespace lemon;
30
31char test_lgf[] =
32  "@nodes\n"
33  "label\n"
34  "1\n"
35  "2\n"
36  "3\n"
37  "4\n"
38  "5\n"
39  "6\n"
40  "7\n"
41  "8\n"
42  "9\n"
43  "10\n"
44  "11\n"
45  "12\n"
46  "@arcs\n"
47  "      length\n"
48  " 1  2  70\n"
49  " 1  3 150\n"
50  " 1  4  80\n"
51  " 2  8  80\n"
52  " 3  5 140\n"
53  " 4  6  60\n"
54  " 4  7  80\n"
55  " 4  8 110\n"
56  " 5  7  60\n"
57  " 5 11 120\n"
58  " 6  3   0\n"
59  " 6  9 140\n"
60  " 6 10  90\n"
61  " 7  1  30\n"
62  " 8 12  60\n"
63  " 9 12  50\n"
64  "10 12  70\n"
65  "10  2 100\n"
66  "10  7  60\n"
67  "11 10  20\n"
68  "12 11  30\n"
69  "@attributes\n"
70  "source  1\n"
71  "target 12\n"
72  "@end\n";
73
74// Check the interface of Suurballe
75void checkSuurballeCompile()
76{
77  typedef int VType;
78  typedef concepts::Digraph Digraph;
79
80  typedef Digraph::Node Node;
81  typedef Digraph::Arc Arc;
82  typedef concepts::ReadMap<Arc, VType> LengthMap;
83
84  typedef Suurballe<Digraph, LengthMap> SuurballeType;
85
86  Digraph g;
87  Node n;
88  Arc e;
89  LengthMap len;
90  SuurballeType::FlowMap flow(g);
91  SuurballeType::PotentialMap pi(g);
92
93  SuurballeType suurb_test(g, len);
94  const SuurballeType& const_suurb_test = suurb_test;
95
96  suurb_test
97    .flowMap(flow)
98    .potentialMap(pi);
99
100  int k;
101  k = suurb_test.run(n, n);
102  k = suurb_test.run(n, n, k);
103  suurb_test.init(n);
104  k = suurb_test.findFlow(n);
105  k = suurb_test.findFlow(n, k);
106  suurb_test.findPaths();
107
108  int f;
109  VType c;
110  ignore_unused_variable_warning(f,c);
111
112  c = const_suurb_test.totalLength();
113  f = const_suurb_test.flow(e);
114  const SuurballeType::FlowMap& fm =
115    const_suurb_test.flowMap();
116  c = const_suurb_test.potential(n);
117  const SuurballeType::PotentialMap& pm =
118    const_suurb_test.potentialMap();
119  k = const_suurb_test.pathNum();
120  Path<Digraph> p = const_suurb_test.path(k);
121
122  ignore_unused_variable_warning(fm);
123  ignore_unused_variable_warning(pm);
124}
125
126// Check the feasibility of the flow
127template <typename Digraph, typename FlowMap>
128bool checkFlow( const Digraph& gr, const FlowMap& flow,
129                typename Digraph::Node s, typename Digraph::Node t,
130                int value )
131{
132  TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
133  for (ArcIt e(gr); e != INVALID; ++e)
134    if (!(flow[e] == 0 || flow[e] == 1)) return false;
135
136  for (NodeIt n(gr); n != INVALID; ++n) {
137    int sum = 0;
138    for (OutArcIt e(gr, n); e != INVALID; ++e)
139      sum += flow[e];
140    for (InArcIt e(gr, n); e != INVALID; ++e)
141      sum -= flow[e];
142    if (n == s && sum != value) return false;
143    if (n == t && sum != -value) return false;
144    if (n != s && n != t && sum != 0) return false;
145  }
146
147  return true;
148}
149
150// Check the optimalitiy of the flow
151template < typename Digraph, typename CostMap,
152           typename FlowMap, typename PotentialMap >
153bool checkOptimality( const Digraph& gr, const CostMap& cost,
154                      const FlowMap& flow, const PotentialMap& pi )
155{
156  // Check the "Complementary Slackness" optimality condition
157  TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
158  bool opt = true;
159  for (ArcIt e(gr); e != INVALID; ++e) {
160    typename CostMap::Value red_cost =
161      cost[e] + pi[gr.source(e)] - pi[gr.target(e)];
162    opt = (flow[e] == 0 && red_cost >= 0) ||
163          (flow[e] == 1 && red_cost <= 0);
164    if (!opt) break;
165  }
166  return opt;
167}
168
169// Check a path
170template <typename Digraph, typename Path>
171bool checkPath( const Digraph& gr, const Path& path,
172                typename Digraph::Node s, typename Digraph::Node t)
173{
174  TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
175  Node n = s;
176  for (int i = 0; i < path.length(); ++i) {
177    if (gr.source(path.nth(i)) != n) return false;
178    n = gr.target(path.nth(i));
179  }
180  return n == t;
181}
182
183
184int main()
185{
186  DIGRAPH_TYPEDEFS(ListDigraph);
187
188  // Read the test digraph
189  ListDigraph digraph;
190  ListDigraph::ArcMap<int> length(digraph);
191  Node s, t;
192
193  std::istringstream input(test_lgf);
194  DigraphReader<ListDigraph>(digraph, input).
195    arcMap("length", length).
196    node("source", s).
197    node("target", t).
198    run();
199
200  // Find 2 paths
201  {
202    Suurballe<ListDigraph> suurballe(digraph, length);
203    check(suurballe.run(s, t) == 2, "Wrong number of paths");
204    check(checkFlow(digraph, suurballe.flowMap(), s, t, 2),
205          "The flow is not feasible");
206    check(suurballe.totalLength() == 510, "The flow is not optimal");
207    check(checkOptimality(digraph, length, suurballe.flowMap(),
208                          suurballe.potentialMap()),
209          "Wrong potentials");
210    for (int i = 0; i < suurballe.pathNum(); ++i)
211      check(checkPath(digraph, suurballe.path(i), s, t), "Wrong path");
212  }
213
214  // Find 3 paths
215  {
216    Suurballe<ListDigraph> suurballe(digraph, length);
217    check(suurballe.run(s, t, 3) == 3, "Wrong number of paths");
218    check(checkFlow(digraph, suurballe.flowMap(), s, t, 3),
219          "The flow is not feasible");
220    check(suurballe.totalLength() == 1040, "The flow is not optimal");
221    check(checkOptimality(digraph, length, suurballe.flowMap(),
222                          suurballe.potentialMap()),
223          "Wrong potentials");
224    for (int i = 0; i < suurballe.pathNum(); ++i)
225      check(checkPath(digraph, suurballe.path(i), s, t), "Wrong path");
226  }
227
228  // Find 5 paths (only 3 can be found)
229  {
230    Suurballe<ListDigraph> suurballe(digraph, length);
231    check(suurballe.run(s, t, 5) == 3, "Wrong number of paths");
232    check(checkFlow(digraph, suurballe.flowMap(), s, t, 3),
233          "The flow is not feasible");
234    check(suurballe.totalLength() == 1040, "The flow is not optimal");
235    check(checkOptimality(digraph, length, suurballe.flowMap(),
236                          suurballe.potentialMap()),
237          "Wrong potentials");
238    for (int i = 0; i < suurballe.pathNum(); ++i)
239      check(checkPath(digraph, suurballe.path(i), s, t), "Wrong path");
240  }
241
242  return 0;
243}
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