test/circulation_test.cc
author Peter Kovacs <kpeter@inf.elte.hu>
Thu, 15 Nov 2012 07:17:48 +0100
changeset 1013 f6f6896a4724
parent 689 86c49553fea5
child 1008 d216e1c8b3fa
permissions -rw-r--r--
Ensure strongly polynomial running time for CycleCanceling (#436)
The number of iterations performed by Howard's algorithm is limited.
If the limit is reached, a strongly polynomial implementation,
HartmannOrlinMmc is executed to find a minimum mean cycle.
This iteration limit is typically not reached, thus the combined
method is practically equivalent to Howard's algorithm, while it
also ensures the strongly polynomial time bound.
     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/list_graph.h>
    23 #include <lemon/circulation.h>
    24 #include <lemon/lgf_reader.h>
    25 #include <lemon/concepts/digraph.h>
    26 #include <lemon/concepts/maps.h>
    27 
    28 using namespace lemon;
    29 
    30 char test_lgf[] =
    31   "@nodes\n"
    32   "label\n"
    33   "0\n"
    34   "1\n"
    35   "2\n"
    36   "3\n"
    37   "4\n"
    38   "5\n"
    39   "@arcs\n"
    40   "     lcap  ucap\n"
    41   "0 1  2  10\n"
    42   "0 2  2  6\n"
    43   "1 3  4  7\n"
    44   "1 4  0  5\n"
    45   "2 4  1  3\n"
    46   "3 5  3  8\n"
    47   "4 5  3  7\n"
    48   "@attributes\n"
    49   "source 0\n"
    50   "sink   5\n";
    51 
    52 void checkCirculationCompile()
    53 {
    54   typedef int VType;
    55   typedef concepts::Digraph Digraph;
    56 
    57   typedef Digraph::Node Node;
    58   typedef Digraph::Arc Arc;
    59   typedef concepts::ReadMap<Arc,VType> CapMap;
    60   typedef concepts::ReadMap<Node,VType> SupplyMap;
    61   typedef concepts::ReadWriteMap<Arc,VType> FlowMap;
    62   typedef concepts::WriteMap<Node,bool> BarrierMap;
    63 
    64   typedef Elevator<Digraph, Digraph::Node> Elev;
    65   typedef LinkedElevator<Digraph, Digraph::Node> LinkedElev;
    66 
    67   Digraph g;
    68   Node n;
    69   Arc a;
    70   CapMap lcap, ucap;
    71   SupplyMap supply;
    72   FlowMap flow;
    73   BarrierMap bar;
    74   VType v;
    75   bool b;
    76 
    77   typedef Circulation<Digraph, CapMap, CapMap, SupplyMap>
    78             ::SetFlowMap<FlowMap>
    79             ::SetElevator<Elev>
    80             ::SetStandardElevator<LinkedElev>
    81             ::Create CirculationType;
    82   CirculationType circ_test(g, lcap, ucap, supply);
    83   const CirculationType& const_circ_test = circ_test;
    84 
    85   circ_test
    86     .lowerMap(lcap)
    87     .upperMap(ucap)
    88     .supplyMap(supply)
    89     .flowMap(flow);
    90 
    91   const CirculationType::Elevator& elev = const_circ_test.elevator();
    92   circ_test.elevator(const_cast<CirculationType::Elevator&>(elev));
    93   CirculationType::Tolerance tol = const_circ_test.tolerance();
    94   circ_test.tolerance(tol);
    95 
    96   circ_test.init();
    97   circ_test.greedyInit();
    98   circ_test.start();
    99   circ_test.run();
   100 
   101   v = const_circ_test.flow(a);
   102   const FlowMap& fm = const_circ_test.flowMap();
   103   b = const_circ_test.barrier(n);
   104   const_circ_test.barrierMap(bar);
   105 
   106   ignore_unused_variable_warning(fm);
   107 }
   108 
   109 template <class G, class LM, class UM, class DM>
   110 void checkCirculation(const G& g, const LM& lm, const UM& um,
   111                       const DM& dm, bool find)
   112 {
   113   Circulation<G, LM, UM, DM> circ(g, lm, um, dm);
   114   bool ret = circ.run();
   115   if (find) {
   116     check(ret, "A feasible solution should have been found.");
   117     check(circ.checkFlow(), "The found flow is corrupt.");
   118     check(!circ.checkBarrier(), "A barrier should not have been found.");
   119   } else {
   120     check(!ret, "A feasible solution should not have been found.");
   121     check(circ.checkBarrier(), "The found barrier is corrupt.");
   122   }
   123 }
   124 
   125 int main (int, char*[])
   126 {
   127   typedef ListDigraph Digraph;
   128   DIGRAPH_TYPEDEFS(Digraph);
   129 
   130   Digraph g;
   131   IntArcMap lo(g), up(g);
   132   IntNodeMap delta(g, 0);
   133   Node s, t;
   134 
   135   std::istringstream input(test_lgf);
   136   DigraphReader<Digraph>(g,input).
   137     arcMap("lcap", lo).
   138     arcMap("ucap", up).
   139     node("source",s).
   140     node("sink",t).
   141     run();
   142 
   143   delta[s] = 7; delta[t] = -7;
   144   checkCirculation(g, lo, up, delta, true);
   145 
   146   delta[s] = 13; delta[t] = -13;
   147   checkCirculation(g, lo, up, delta, true);
   148 
   149   delta[s] = 6; delta[t] = -6;
   150   checkCirculation(g, lo, up, delta, false);
   151 
   152   delta[s] = 14; delta[t] = -14;
   153   checkCirculation(g, lo, up, delta, false);
   154 
   155   delta[s] = 7; delta[t] = -13;
   156   checkCirculation(g, lo, up, delta, true);
   157 
   158   delta[s] = 5; delta[t] = -15;
   159   checkCirculation(g, lo, up, delta, true);
   160 
   161   delta[s] = 10; delta[t] = -11;
   162   checkCirculation(g, lo, up, delta, true);
   163 
   164   delta[s] = 11; delta[t] = -10;
   165   checkCirculation(g, lo, up, delta, false);
   166 
   167   return 0;
   168 }