alpar@440: /* -*- mode: C++; indent-tabs-mode: nil; -*-
alpar@345:  *
alpar@440:  * This file is a part of LEMON, a generic C++ optimization library.
alpar@345:  *
alpar@761:  * Copyright (C) 2003-2011
alpar@345:  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
alpar@345:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
alpar@345:  *
alpar@345:  * Permission to use, modify and distribute this software is granted
alpar@345:  * provided that this copyright notice appears in all copies. For
alpar@345:  * precise terms see the accompanying LICENSE file.
alpar@345:  *
alpar@345:  * This software is provided "AS IS" with no warranty of any kind,
alpar@345:  * express or implied, and with no claim as to its suitability for any
alpar@345:  * purpose.
alpar@345:  *
alpar@345:  */
alpar@345: 
alpar@345: #include <iostream>
alpar@345: 
alpar@345: #include <lemon/list_graph.h>
alpar@345: #include <lemon/lgf_reader.h>
alpar@345: #include <lemon/path.h>
alpar@345: #include <lemon/suurballe.h>
kpeter@615: #include <lemon/concepts/digraph.h>
alpar@345: 
alpar@345: #include "test_tools.h"
alpar@345: 
alpar@345: using namespace lemon;
alpar@345: 
alpar@423: char test_lgf[] =
alpar@423:   "@nodes\n"
kpeter@615:   "label\n"
kpeter@615:   "1\n"
kpeter@615:   "2\n"
kpeter@615:   "3\n"
kpeter@615:   "4\n"
kpeter@615:   "5\n"
kpeter@615:   "6\n"
kpeter@615:   "7\n"
kpeter@615:   "8\n"
kpeter@615:   "9\n"
kpeter@615:   "10\n"
kpeter@615:   "11\n"
kpeter@615:   "12\n"
alpar@423:   "@arcs\n"
kpeter@615:   "      length\n"
kpeter@615:   " 1  2  70\n"
kpeter@615:   " 1  3 150\n"
kpeter@615:   " 1  4  80\n"
kpeter@615:   " 2  8  80\n"
kpeter@615:   " 3  5 140\n"
kpeter@615:   " 4  6  60\n"
kpeter@615:   " 4  7  80\n"
kpeter@615:   " 4  8 110\n"
kpeter@615:   " 5  7  60\n"
kpeter@615:   " 5 11 120\n"
kpeter@615:   " 6  3   0\n"
kpeter@615:   " 6  9 140\n"
kpeter@615:   " 6 10  90\n"
kpeter@615:   " 7  1  30\n"
kpeter@615:   " 8 12  60\n"
kpeter@615:   " 9 12  50\n"
kpeter@615:   "10 12  70\n"
kpeter@615:   "10  2 100\n"
kpeter@615:   "10  7  60\n"
kpeter@615:   "11 10  20\n"
kpeter@615:   "12 11  30\n"
alpar@423:   "@attributes\n"
alpar@423:   "source  1\n"
alpar@423:   "target 12\n"
alpar@423:   "@end\n";
alpar@423: 
kpeter@615: // Check the interface of Suurballe
kpeter@615: void checkSuurballeCompile()
kpeter@615: {
kpeter@615:   typedef int VType;
kpeter@615:   typedef concepts::Digraph Digraph;
kpeter@615: 
kpeter@615:   typedef Digraph::Node Node;
kpeter@615:   typedef Digraph::Arc Arc;
kpeter@615:   typedef concepts::ReadMap<Arc, VType> LengthMap;
alpar@761: 
kpeter@615:   typedef Suurballe<Digraph, LengthMap> SuurballeType;
kpeter@615: 
kpeter@615:   Digraph g;
kpeter@615:   Node n;
kpeter@615:   Arc e;
kpeter@615:   LengthMap len;
kpeter@615:   SuurballeType::FlowMap flow(g);
kpeter@615:   SuurballeType::PotentialMap pi(g);
kpeter@615: 
kpeter@615:   SuurballeType suurb_test(g, len);
kpeter@615:   const SuurballeType& const_suurb_test = suurb_test;
kpeter@615: 
kpeter@615:   suurb_test
kpeter@615:     .flowMap(flow)
kpeter@615:     .potentialMap(pi);
kpeter@615: 
kpeter@615:   int k;
kpeter@615:   k = suurb_test.run(n, n);
kpeter@615:   k = suurb_test.run(n, n, k);
kpeter@615:   suurb_test.init(n);
kpeter@615:   k = suurb_test.findFlow(n);
kpeter@615:   k = suurb_test.findFlow(n, k);
kpeter@615:   suurb_test.findPaths();
alpar@761: 
kpeter@615:   int f;
kpeter@615:   VType c;
kpeter@615:   c = const_suurb_test.totalLength();
kpeter@615:   f = const_suurb_test.flow(e);
kpeter@615:   const SuurballeType::FlowMap& fm =
kpeter@615:     const_suurb_test.flowMap();
kpeter@615:   c = const_suurb_test.potential(n);
kpeter@615:   const SuurballeType::PotentialMap& pm =
kpeter@615:     const_suurb_test.potentialMap();
kpeter@615:   k = const_suurb_test.pathNum();
kpeter@615:   Path<Digraph> p = const_suurb_test.path(k);
alpar@761: 
kpeter@615:   ignore_unused_variable_warning(fm);
kpeter@615:   ignore_unused_variable_warning(pm);
kpeter@615: }
kpeter@615: 
kpeter@346: // Check the feasibility of the flow
alpar@345: template <typename Digraph, typename FlowMap>
alpar@440: bool checkFlow( const Digraph& gr, const FlowMap& flow,
alpar@345:                 typename Digraph::Node s, typename Digraph::Node t,
alpar@345:                 int value )
alpar@345: {
alpar@345:   TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
alpar@345:   for (ArcIt e(gr); e != INVALID; ++e)
alpar@345:     if (!(flow[e] == 0 || flow[e] == 1)) return false;
alpar@345: 
alpar@345:   for (NodeIt n(gr); n != INVALID; ++n) {
alpar@345:     int sum = 0;
alpar@345:     for (OutArcIt e(gr, n); e != INVALID; ++e)
alpar@345:       sum += flow[e];
alpar@345:     for (InArcIt e(gr, n); e != INVALID; ++e)
alpar@345:       sum -= flow[e];
alpar@345:     if (n == s && sum != value) return false;
alpar@345:     if (n == t && sum != -value) return false;
alpar@345:     if (n != s && n != t && sum != 0) return false;
alpar@345:   }
alpar@345: 
alpar@345:   return true;
alpar@345: }
alpar@345: 
kpeter@346: // Check the optimalitiy of the flow
alpar@440: template < typename Digraph, typename CostMap,
alpar@345:            typename FlowMap, typename PotentialMap >
alpar@345: bool checkOptimality( const Digraph& gr, const CostMap& cost,
alpar@345:                       const FlowMap& flow, const PotentialMap& pi )
alpar@345: {
kpeter@346:   // Check the "Complementary Slackness" optimality condition
alpar@345:   TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
alpar@345:   bool opt = true;
alpar@345:   for (ArcIt e(gr); e != INVALID; ++e) {
alpar@345:     typename CostMap::Value red_cost =
alpar@345:       cost[e] + pi[gr.source(e)] - pi[gr.target(e)];
alpar@345:     opt = (flow[e] == 0 && red_cost >= 0) ||
alpar@345:           (flow[e] == 1 && red_cost <= 0);
alpar@345:     if (!opt) break;
alpar@345:   }
alpar@345:   return opt;
alpar@345: }
alpar@345: 
kpeter@346: // Check a path
kpeter@346: template <typename Digraph, typename Path>
alpar@345: bool checkPath( const Digraph& gr, const Path& path,
alpar@345:                 typename Digraph::Node s, typename Digraph::Node t)
alpar@345: {
alpar@345:   TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
alpar@345:   Node n = s;
alpar@345:   for (int i = 0; i < path.length(); ++i) {
alpar@345:     if (gr.source(path.nth(i)) != n) return false;
alpar@345:     n = gr.target(path.nth(i));
alpar@345:   }
alpar@345:   return n == t;
alpar@345: }
alpar@345: 
alpar@345: 
alpar@345: int main()
alpar@345: {
alpar@345:   DIGRAPH_TYPEDEFS(ListDigraph);
alpar@345: 
kpeter@346:   // Read the test digraph
alpar@345:   ListDigraph digraph;
alpar@345:   ListDigraph::ArcMap<int> length(digraph);
kpeter@615:   Node s, t;
alpar@345: 
alpar@423:   std::istringstream input(test_lgf);
alpar@345:   DigraphReader<ListDigraph>(digraph, input).
kpeter@615:     arcMap("length", length).
kpeter@615:     node("source", s).
kpeter@615:     node("target", t).
alpar@345:     run();
alpar@440: 
kpeter@346:   // Find 2 paths
alpar@345:   {
kpeter@615:     Suurballe<ListDigraph> suurballe(digraph, length);
kpeter@615:     check(suurballe.run(s, t) == 2, "Wrong number of paths");
kpeter@615:     check(checkFlow(digraph, suurballe.flowMap(), s, t, 2),
alpar@345:           "The flow is not feasible");
alpar@345:     check(suurballe.totalLength() == 510, "The flow is not optimal");
alpar@440:     check(checkOptimality(digraph, length, suurballe.flowMap(),
alpar@345:                           suurballe.potentialMap()),
alpar@345:           "Wrong potentials");
alpar@345:     for (int i = 0; i < suurballe.pathNum(); ++i)
kpeter@615:       check(checkPath(digraph, suurballe.path(i), s, t), "Wrong path");
alpar@345:   }
alpar@345: 
kpeter@346:   // Find 3 paths
alpar@345:   {
kpeter@615:     Suurballe<ListDigraph> suurballe(digraph, length);
kpeter@615:     check(suurballe.run(s, t, 3) == 3, "Wrong number of paths");
kpeter@615:     check(checkFlow(digraph, suurballe.flowMap(), s, t, 3),
alpar@345:           "The flow is not feasible");
alpar@345:     check(suurballe.totalLength() == 1040, "The flow is not optimal");
alpar@440:     check(checkOptimality(digraph, length, suurballe.flowMap(),
alpar@345:                           suurballe.potentialMap()),
alpar@345:           "Wrong potentials");
alpar@345:     for (int i = 0; i < suurballe.pathNum(); ++i)
kpeter@615:       check(checkPath(digraph, suurballe.path(i), s, t), "Wrong path");
alpar@345:   }
alpar@345: 
kpeter@346:   // Find 5 paths (only 3 can be found)
alpar@345:   {
kpeter@615:     Suurballe<ListDigraph> suurballe(digraph, length);
kpeter@615:     check(suurballe.run(s, t, 5) == 3, "Wrong number of paths");
kpeter@615:     check(checkFlow(digraph, suurballe.flowMap(), s, t, 3),
alpar@345:           "The flow is not feasible");
alpar@345:     check(suurballe.totalLength() == 1040, "The flow is not optimal");
alpar@440:     check(checkOptimality(digraph, length, suurballe.flowMap(),
alpar@345:                           suurballe.potentialMap()),
alpar@345:           "Wrong potentials");
alpar@345:     for (int i = 0; i < suurballe.pathNum(); ++i)
kpeter@615:       check(checkPath(digraph, suurballe.path(i), s, t), "Wrong path");
alpar@345:   }
alpar@345: 
alpar@345:   return 0;
alpar@345: }