/* -*- mode: C++; indent-tabs-mode: nil; -*-

  *

  * This file is a part of LEMON, a generic C++ optimization library.

  *

  * Copyright (C) 2003-2009

  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

  * (Egervary Research Group on Combinatorial Optimization, EGRES).

  *

  * Permission to use, modify and distribute this software is granted

  * provided that this copyright notice appears in all copies. For

  * precise terms see the accompanying LICENSE file.

  *

  * This software is provided "AS IS" with no warranty of any kind,

  * express or implied, and with no claim as to its suitability for any

  * purpose.

  *

  */

 #include <iostream>

 #include <fstream>

 #include <lemon/list_graph.h>

 #include <lemon/lgf_reader.h>

 #include <lemon/network_simplex.h>

 #include <lemon/concepts/digraph.h>

 #include <lemon/concept_check.h>

 #include "test_tools.h"

 using namespace lemon;

 char test_lgf[] =

   "@nodes\n"

   "label  sup1 sup2 sup3\n"

   "    1    20   27    0\n"

   "    2    -4    0    0\n"

   "    3     0    0    0\n"

   "    4     0    0    0\n"

   "    5     9    0    0\n"

   "    6    -6    0    0\n"

   "    7     0    0    0\n"

   "    8     0    0    0\n"

   "    9     3    0    0\n"

   "   10    -2    0    0\n"

   "   11     0    0    0\n"

   "   12   -20  -27    0\n"

   "\n"

   "@arcs\n"

   "       cost  cap low1 low2\n"

   " 1  2    70   11    0    8\n"

   " 1  3   150    3    0    1\n"

   " 1  4    80   15    0    2\n"

   " 2  8    80   12    0    0\n"

   " 3  5   140    5    0    3\n"

   " 4  6    60   10    0    1\n"

   " 4  7    80    2    0    0\n"

   " 4  8   110    3    0    0\n"

   " 5  7    60   14    0    0\n"

   " 5 11   120   12    0    0\n"

   " 6  3     0    3    0    0\n"

   " 6  9   140    4    0    0\n"

   " 6 10    90    8    0    0\n"

   " 7  1    30    5    0    0\n"

   " 8 12    60   16    0    4\n"

   " 9 12    50    6    0    0\n"

   "10 12    70   13    0    5\n"

   "10  2   100    7    0    0\n"

   "10  7    60   10    0    0\n"

   "11 10    20   14    0    6\n"

   "12 11    30   10    0    0\n"

   "\n"

   "@attributes\n"

   "source 1\n"

   "target 12\n";

 // Check the interface of an MCF algorithm

 template <typename GR, typename Value>

 class McfClassConcept

 {

 public:

   template <typename MCF>

   struct Constraints {

     void constraints() {

       checkConcept<concepts::Digraph, GR>();

       MCF mcf(g);

       b = mcf.reset()

              .lowerMap(lower)

              .upperMap(upper)

              .capacityMap(upper)

              .boundMaps(lower, upper)

              .costMap(cost)

              .supplyMap(sup)

              .stSupply(n, n, k)

              .run();

       const typename MCF::FlowMap &fm = mcf.flowMap();

       const typename MCF::PotentialMap &pm = mcf.potentialMap();

       v = mcf.totalCost();

       double x = mcf.template totalCost<double>();

       v = mcf.flow(a);

       v = mcf.potential(n);

       mcf.flowMap(flow);

       mcf.potentialMap(pot);

       ignore_unused_variable_warning(fm);

       ignore_unused_variable_warning(pm);

       ignore_unused_variable_warning(x);

     }

     typedef typename GR::Node Node;

     typedef typename GR::Arc Arc;

     typedef concepts::ReadMap<Node, Value> NM;

     typedef concepts::ReadMap<Arc, Value> AM;

     const GR &g;

     const AM &lower;

     const AM &upper;

     const AM &cost;

     const NM ⊃

     const Node &n;

     const Arc &a;

     const Value &k;

     Value v;

     bool b;

     typename MCF::FlowMap &flow;

     typename MCF::PotentialMap &pot;

   };

 };

 // Check the feasibility of the given flow (primal soluiton)

 template < typename GR, typename LM, typename UM,

            typename SM, typename FM >

 bool checkFlow( const GR& gr, const LM& lower, const UM& upper,

                 const SM& supply, const FM& flow )

 {

   TEMPLATE_DIGRAPH_TYPEDEFS(GR);

   for (ArcIt e(gr); e != INVALID; ++e) {

     if (flow[e] < lower[e] || flow[e] > upper[e]) return false;

   }

   for (NodeIt n(gr); n != INVALID; ++n) {

     typename SM::Value sum = 0;

     for (OutArcIt e(gr, n); e != INVALID; ++e)

       sum += flow[e];

     for (InArcIt e(gr, n); e != INVALID; ++e)

       sum -= flow[e];

     if (sum != supply[n]) return false;

   }

   return true;

 }

 // Check the feasibility of the given potentials (dual soluiton)

 // using the "Complementary Slackness" optimality condition

 template < typename GR, typename LM, typename UM,

            typename CM, typename FM, typename PM >

 bool checkPotential( const GR& gr, const LM& lower, const UM& upper,

                      const CM& cost, const FM& flow, const PM& pi )

 {

   TEMPLATE_DIGRAPH_TYPEDEFS(GR);

   bool opt = true;

   for (ArcIt e(gr); opt && e != INVALID; ++e) {

     typename CM::Value red_cost =

       cost[e] + pi[gr.source(e)] - pi[gr.target(e)];

     opt = red_cost == 0 ||

           (red_cost > 0 && flow[e] == lower[e]) ||

           (red_cost < 0 && flow[e] == upper[e]);

   }

   return opt;

 }

 // Run a minimum cost flow algorithm and check the results

 template < typename MCF, typename GR,

            typename LM, typename UM,

            typename CM, typename SM >

 void checkMcf( const MCF& mcf, bool mcf_result,

                const GR& gr, const LM& lower, const UM& upper,

                const CM& cost, const SM& supply,

                bool result, typename CM::Value total,

                const std::string &test_id = "" )

 {

   check(mcf_result == result, "Wrong result " + test_id);

   if (result) {

     check(checkFlow(gr, lower, upper, supply, mcf.flowMap()),

           "The flow is not feasible " + test_id);

     check(mcf.totalCost() == total, "The flow is not optimal " + test_id);

     check(checkPotential(gr, lower, upper, cost, mcf.flowMap(),

                          mcf.potentialMap()),

           "Wrong potentials " + test_id);

   }

 }

 int main()

 {

   // Check the interfaces

   {

     typedef int Value;

     // TODO: This typedef should be enabled if the standard maps are

     // reference maps in the graph concepts (See #190).

 /**/

     //typedef concepts::Digraph GR;

     typedef ListDigraph GR;

 /**/

     checkConcept< McfClassConcept<GR, Value>,

                   NetworkSimplex<GR, Value> >();

   }

   // Run various MCF tests

   typedef ListDigraph Digraph;

   DIGRAPH_TYPEDEFS(ListDigraph);

   // Read the test digraph

   Digraph gr;

   Digraph::ArcMap<int> c(gr), l1(gr), l2(gr), u(gr);

   Digraph::NodeMap<int> s1(gr), s2(gr), s3(gr);

   ConstMap<Arc, int> cc(1), cu(std::numeric_limits<int>::max());

   Node v, w;

   std::istringstream input(test_lgf);

   DigraphReader<Digraph>(gr, input)

     .arcMap("cost", c)

     .arcMap("cap", u)

     .arcMap("low1", l1)

     .arcMap("low2", l2)

     .nodeMap("sup1", s1)

     .nodeMap("sup2", s2)

     .nodeMap("sup3", s3)

     .node("source", v)

     .node("target", w)

     .run();

   // A. Test NetworkSimplex with the default pivot rule

   {

     NetworkSimplex<Digraph> mcf(gr);

     mcf.upperMap(u).costMap(c);

     checkMcf(mcf, mcf.supplyMap(s1).run(),

              gr, l1, u, c, s1, true,  5240, "#A1");

     checkMcf(mcf, mcf.stSupply(v, w, 27).run(),

              gr, l1, u, c, s2, true,  7620, "#A2");

     mcf.lowerMap(l2);

     checkMcf(mcf, mcf.supplyMap(s1).run(),

              gr, l2, u, c, s1, true,  5970, "#A3");

     checkMcf(mcf, mcf.stSupply(v, w, 27).run(),

              gr, l2, u, c, s2, true,  8010, "#A4");

     mcf.reset();

     checkMcf(mcf, mcf.supplyMap(s1).run(),

              gr, l1, cu, cc, s1, true,  74, "#A5");

     checkMcf(mcf, mcf.lowerMap(l2).stSupply(v, w, 27).run(),

              gr, l2, cu, cc, s2, true,  94, "#A6");

     mcf.reset();

     checkMcf(mcf, mcf.run(),

              gr, l1, cu, cc, s3, true,   0, "#A7");

     checkMcf(mcf, mcf.boundMaps(l2, u).run(),

              gr, l2, u, cc, s3, false,   0, "#A8");

   }

   // B. Test NetworkSimplex with each pivot rule

   {

     NetworkSimplex<Digraph> mcf(gr);

     mcf.supplyMap(s1).costMap(c).capacityMap(u).lowerMap(l2);

     checkMcf(mcf, mcf.run(NetworkSimplex<Digraph>::FIRST_ELIGIBLE),

              gr, l2, u, c, s1, true,  5970, "#B1");

     checkMcf(mcf, mcf.run(NetworkSimplex<Digraph>::BEST_ELIGIBLE),

              gr, l2, u, c, s1, true,  5970, "#B2");

     checkMcf(mcf, mcf.run(NetworkSimplex<Digraph>::BLOCK_SEARCH),

              gr, l2, u, c, s1, true,  5970, "#B3");

     checkMcf(mcf, mcf.run(NetworkSimplex<Digraph>::CANDIDATE_LIST),

              gr, l2, u, c, s1, true,  5970, "#B4");

     checkMcf(mcf, mcf.run(NetworkSimplex<Digraph>::ALTERING_LIST),

              gr, l2, u, c, s1, true,  5970, "#B5");

   }

   return 0;

 }