COIN-OR::LEMON - Graph Library

source: lemon-1.2/test/suurballe_test.cc @ 857:abb95d48e89e

Last change on this file since 857:abb95d48e89e was 857:abb95d48e89e, checked in by Peter Kovacs <kpeter@…>, 10 years ago

Add traits class + named parameters to Suurballe (#323)

The following types can be modified using named parameters:

File size: 6.7 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) 2003-2009
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#include <lemon/concepts/heap.h>
27
28#include "test_tools.h"
29
30using namespace lemon;
31
32char test_lgf[] =
33  "@nodes\n"
34  "label\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  "10\n"
45  "11\n"
46  "12\n"
47  "@arcs\n"
48  "      length\n"
49  " 1  2  70\n"
50  " 1  3 150\n"
51  " 1  4  80\n"
52  " 2  8  80\n"
53  " 3  5 140\n"
54  " 4  6  60\n"
55  " 4  7  80\n"
56  " 4  8 110\n"
57  " 5  7  60\n"
58  " 5 11 120\n"
59  " 6  3   0\n"
60  " 6  9 140\n"
61  " 6 10  90\n"
62  " 7  1  30\n"
63  " 8 12  60\n"
64  " 9 12  50\n"
65  "10 12  70\n"
66  "10  2 100\n"
67  "10  7  60\n"
68  "11 10  20\n"
69  "12 11  30\n"
70  "@attributes\n"
71  "source  1\n"
72  "target 12\n"
73  "@end\n";
74
75// Check the interface of Suurballe
76void checkSuurballeCompile()
77{
78  typedef int VType;
79  typedef concepts::Digraph Digraph;
80
81  typedef Digraph::Node Node;
82  typedef Digraph::Arc Arc;
83  typedef concepts::ReadMap<Arc, VType> LengthMap;
84 
85  typedef Suurballe<Digraph, LengthMap> ST;
86  typedef Suurballe<Digraph, LengthMap>
87    ::SetFlowMap<ST::FlowMap>
88    ::SetPotentialMap<ST::PotentialMap>
89    ::SetPath<SimplePath<Digraph> >
90    ::SetHeap<concepts::Heap<VType, Digraph::NodeMap<int> > >
91    ::Create SuurballeType;
92
93  Digraph g;
94  Node n;
95  Arc e;
96  LengthMap len;
97  SuurballeType::FlowMap flow(g);
98  SuurballeType::PotentialMap pi(g);
99
100  SuurballeType suurb_test(g, len);
101  const SuurballeType& const_suurb_test = suurb_test;
102
103  suurb_test
104    .flowMap(flow)
105    .potentialMap(pi);
106
107  int k;
108  k = suurb_test.run(n, n);
109  k = suurb_test.run(n, n, k);
110  suurb_test.init(n);
111  suurb_test.fullInit(n);
112  suurb_test.start(n);
113  suurb_test.start(n, k);
114  k = suurb_test.findFlow(n);
115  k = suurb_test.findFlow(n, k);
116  suurb_test.findPaths();
117 
118  int f;
119  VType c;
120  c = const_suurb_test.totalLength();
121  f = const_suurb_test.flow(e);
122  const SuurballeType::FlowMap& fm =
123    const_suurb_test.flowMap();
124  c = const_suurb_test.potential(n);
125  const SuurballeType::PotentialMap& pm =
126    const_suurb_test.potentialMap();
127  k = const_suurb_test.pathNum();
128  Path<Digraph> p = const_suurb_test.path(k);
129 
130  ignore_unused_variable_warning(fm);
131  ignore_unused_variable_warning(pm);
132}
133
134// Check the feasibility of the flow
135template <typename Digraph, typename FlowMap>
136bool checkFlow( const Digraph& gr, const FlowMap& flow,
137                typename Digraph::Node s, typename Digraph::Node t,
138                int value )
139{
140  TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
141  for (ArcIt e(gr); e != INVALID; ++e)
142    if (!(flow[e] == 0 || flow[e] == 1)) return false;
143
144  for (NodeIt n(gr); n != INVALID; ++n) {
145    int sum = 0;
146    for (OutArcIt e(gr, n); e != INVALID; ++e)
147      sum += flow[e];
148    for (InArcIt e(gr, n); e != INVALID; ++e)
149      sum -= flow[e];
150    if (n == s && sum != value) return false;
151    if (n == t && sum != -value) return false;
152    if (n != s && n != t && sum != 0) return false;
153  }
154
155  return true;
156}
157
158// Check the optimalitiy of the flow
159template < typename Digraph, typename CostMap,
160           typename FlowMap, typename PotentialMap >
161bool checkOptimality( const Digraph& gr, const CostMap& cost,
162                      const FlowMap& flow, const PotentialMap& pi )
163{
164  // Check the "Complementary Slackness" optimality condition
165  TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
166  bool opt = true;
167  for (ArcIt e(gr); e != INVALID; ++e) {
168    typename CostMap::Value red_cost =
169      cost[e] + pi[gr.source(e)] - pi[gr.target(e)];
170    opt = (flow[e] == 0 && red_cost >= 0) ||
171          (flow[e] == 1 && red_cost <= 0);
172    if (!opt) break;
173  }
174  return opt;
175}
176
177// Check a path
178template <typename Digraph, typename Path>
179bool checkPath( const Digraph& gr, const Path& path,
180                typename Digraph::Node s, typename Digraph::Node t)
181{
182  TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
183  Node n = s;
184  for (int i = 0; i < path.length(); ++i) {
185    if (gr.source(path.nth(i)) != n) return false;
186    n = gr.target(path.nth(i));
187  }
188  return n == t;
189}
190
191
192int main()
193{
194  DIGRAPH_TYPEDEFS(ListDigraph);
195
196  // Read the test digraph
197  ListDigraph digraph;
198  ListDigraph::ArcMap<int> length(digraph);
199  Node s, t;
200
201  std::istringstream input(test_lgf);
202  DigraphReader<ListDigraph>(digraph, input).
203    arcMap("length", length).
204    node("source", s).
205    node("target", t).
206    run();
207
208  // Find 2 paths
209  {
210    Suurballe<ListDigraph> suurballe(digraph, length);
211    check(suurballe.run(s, t) == 2, "Wrong number of paths");
212    check(checkFlow(digraph, suurballe.flowMap(), s, t, 2),
213          "The flow is not feasible");
214    check(suurballe.totalLength() == 510, "The flow is not optimal");
215    check(checkOptimality(digraph, length, suurballe.flowMap(),
216                          suurballe.potentialMap()),
217          "Wrong potentials");
218    for (int i = 0; i < suurballe.pathNum(); ++i)
219      check(checkPath(digraph, suurballe.path(i), s, t), "Wrong path");
220  }
221
222  // Find 3 paths
223  {
224    Suurballe<ListDigraph> suurballe(digraph, length);
225    check(suurballe.run(s, t, 3) == 3, "Wrong number of paths");
226    check(checkFlow(digraph, suurballe.flowMap(), s, t, 3),
227          "The flow is not feasible");
228    check(suurballe.totalLength() == 1040, "The flow is not optimal");
229    check(checkOptimality(digraph, length, suurballe.flowMap(),
230                          suurballe.potentialMap()),
231          "Wrong potentials");
232    for (int i = 0; i < suurballe.pathNum(); ++i)
233      check(checkPath(digraph, suurballe.path(i), s, t), "Wrong path");
234  }
235
236  // Find 5 paths (only 3 can be found)
237  {
238    Suurballe<ListDigraph> suurballe(digraph, length);
239    check(suurballe.run(s, t, 5) == 3, "Wrong number of paths");
240    check(checkFlow(digraph, suurballe.flowMap(), s, t, 3),
241          "The flow is not feasible");
242    check(suurballe.totalLength() == 1040, "The flow is not optimal");
243    check(checkOptimality(digraph, length, suurballe.flowMap(),
244                          suurballe.potentialMap()),
245          "Wrong potentials");
246    for (int i = 0; i < suurballe.pathNum(); ++i)
247      check(checkPath(digraph, suurballe.path(i), s, t), "Wrong path");
248  }
249
250  return 0;
251}
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