diff -r c35afa9e89e7 -r ef88c0a30f85 test/min_cost_flow_test.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/min_cost_flow_test.cc	Thu Nov 05 15:48:01 2009 +0100
@@ -0,0 +1,450 @@
+/* -*- 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 <limits>
+
+#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 sup4 sup5 sup6\n"
+  "    1    20   27    0   30   20   30\n"
+  "    2    -4    0    0    0   -8   -3\n"
+  "    3     0    0    0    0    0    0\n"
+  "    4     0    0    0    0    0    0\n"
+  "    5     9    0    0    0    6   11\n"
+  "    6    -6    0    0    0   -5   -6\n"
+  "    7     0    0    0    0    0    0\n"
+  "    8     0    0    0    0    0    3\n"
+  "    9     3    0    0    0    0    0\n"
+  "   10    -2    0    0    0   -7   -2\n"
+  "   11     0    0    0    0  -10    0\n"
+  "   12   -20  -27    0  -30  -30  -20\n"
+  "\n"                
+  "@arcs\n"
+  "       cost  cap low1 low2 low3\n"
+  " 1  2    70   11    0    8    8\n"
+  " 1  3   150    3    0    1    0\n"
+  " 1  4    80   15    0    2    2\n"
+  " 2  8    80   12    0    0    0\n"
+  " 3  5   140    5    0    3    1\n"
+  " 4  6    60   10    0    1    0\n"
+  " 4  7    80    2    0    0    0\n"
+  " 4  8   110    3    0    0    0\n"
+  " 5  7    60   14    0    0    0\n"
+  " 5 11   120   12    0    0    0\n"
+  " 6  3     0    3    0    0    0\n"
+  " 6  9   140    4    0    0    0\n"
+  " 6 10    90    8    0    0    0\n"
+  " 7  1    30    5    0    0   -5\n"
+  " 8 12    60   16    0    4    3\n"
+  " 9 12    50    6    0    0    0\n"
+  "10 12    70   13    0    5    2\n"
+  "10  2   100    7    0    0    0\n"
+  "10  7    60   10    0    0   -3\n"
+  "11 10    20   14    0    6  -20\n"
+  "12 11    30   10    0    0  -10\n"
+  "\n"
+  "@attributes\n"
+  "source 1\n"
+  "target 12\n";
+
+
+enum SupplyType {
+  EQ,
+  GEQ,
+  LEQ
+};
+
+// Check the interface of an MCF algorithm
+template <typename GR, typename Value, typename Cost>
+class McfClassConcept
+{
+public:
+
+  template <typename MCF>
+  struct Constraints {
+    void constraints() {
+      checkConcept<concepts::Digraph, GR>();
+      
+      const Constraints& me = *this;
+
+      MCF mcf(me.g);
+      const MCF& const_mcf = mcf;
+
+      b = mcf.reset()
+             .lowerMap(me.lower)
+             .upperMap(me.upper)
+             .costMap(me.cost)
+             .supplyMap(me.sup)
+             .stSupply(me.n, me.n, me.k)
+             .run();
+
+      c = const_mcf.totalCost();
+      x = const_mcf.template totalCost<double>();
+      v = const_mcf.flow(me.a);
+      c = const_mcf.potential(me.n);
+      const_mcf.flowMap(fm);
+      const_mcf.potentialMap(pm);
+    }
+
+    typedef typename GR::Node Node;
+    typedef typename GR::Arc Arc;
+    typedef concepts::ReadMap<Node, Value> NM;
+    typedef concepts::ReadMap<Arc, Value> VAM;
+    typedef concepts::ReadMap<Arc, Cost> CAM;
+    typedef concepts::WriteMap<Arc, Value> FlowMap;
+    typedef concepts::WriteMap<Node, Cost> PotMap;
+  
+    GR g;
+    VAM lower;
+    VAM upper;
+    CAM cost;
+    NM sup;
+    Node n;
+    Arc a;
+    Value k;
+
+    FlowMap fm;
+    PotMap pm;
+    bool b;
+    double x;
+    typename MCF::Value v;
+    typename MCF::Cost c;
+  };
+
+};
+
+
+// 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,
+                SupplyType type = EQ )
+{
+  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];
+    bool b = (type ==  EQ && sum == supply[n]) ||
+             (type == GEQ && sum >= supply[n]) ||
+             (type == LEQ && sum <= supply[n]);
+    if (!b) 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 SM, typename FM, typename PM >
+bool checkPotential( const GR& gr, const LM& lower, const UM& upper,
+                     const CM& cost, const SM& supply, const FM& flow, 
+                     const PM& pi, SupplyType type )
+{
+  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]);
+  }
+  
+  for (NodeIt n(gr); opt && 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 (type != LEQ) {
+      opt = (pi[n] <= 0) && (sum == supply[n] || pi[n] == 0);
+    } else {
+      opt = (pi[n] >= 0) && (sum == supply[n] || pi[n] == 0);
+    }
+  }
+  
+  return opt;
+}
+
+// Check whether the dual cost is equal to the primal cost
+template < typename GR, typename LM, typename UM,
+           typename CM, typename SM, typename PM >
+bool checkDualCost( const GR& gr, const LM& lower, const UM& upper,
+                    const CM& cost, const SM& supply, const PM& pi,
+                    typename CM::Value total )
+{
+  TEMPLATE_DIGRAPH_TYPEDEFS(GR);
+
+  typename CM::Value dual_cost = 0;
+  SM red_supply(gr);
+  for (NodeIt n(gr); n != INVALID; ++n) {
+    red_supply[n] = supply[n];
+  }
+  for (ArcIt a(gr); a != INVALID; ++a) {
+    if (lower[a] != 0) {
+      dual_cost += lower[a] * cost[a];
+      red_supply[gr.source(a)] -= lower[a];
+      red_supply[gr.target(a)] += lower[a];
+    }
+  }
+  
+  for (NodeIt n(gr); n != INVALID; ++n) {
+    dual_cost -= red_supply[n] * pi[n];
+  }
+  for (ArcIt a(gr); a != INVALID; ++a) {
+    typename CM::Value red_cost =
+      cost[a] + pi[gr.source(a)] - pi[gr.target(a)];
+    dual_cost -= (upper[a] - lower[a]) * std::max(-red_cost, 0);
+  }
+  
+  return dual_cost == total;
+}
+
+// Run a minimum cost flow algorithm and check the results
+template < typename MCF, typename GR,
+           typename LM, typename UM,
+           typename CM, typename SM,
+           typename PT >
+void checkMcf( const MCF& mcf, PT mcf_result,
+               const GR& gr, const LM& lower, const UM& upper,
+               const CM& cost, const SM& supply,
+               PT result, bool optimal, typename CM::Value total,
+               const std::string &test_id = "",
+               SupplyType type = EQ )
+{
+  check(mcf_result == result, "Wrong result " + test_id);
+  if (optimal) {
+    typename GR::template ArcMap<typename SM::Value> flow(gr);
+    typename GR::template NodeMap<typename CM::Value> pi(gr);
+    mcf.flowMap(flow);
+    mcf.potentialMap(pi);
+    check(checkFlow(gr, lower, upper, supply, flow, type),
+          "The flow is not feasible " + test_id);
+    check(mcf.totalCost() == total, "The flow is not optimal " + test_id);
+    check(checkPotential(gr, lower, upper, cost, supply, flow, pi, type),
+          "Wrong potentials " + test_id);
+    check(checkDualCost(gr, lower, upper, cost, supply, pi, total),
+          "Wrong dual cost " + test_id);
+  }
+}
+
+int main()
+{
+  // Check the interfaces
+  {
+    typedef concepts::Digraph GR;
+    checkConcept< McfClassConcept<GR, int, int>,
+                  NetworkSimplex<GR> >();
+    checkConcept< McfClassConcept<GR, double, double>,
+                  NetworkSimplex<GR, double> >();
+    checkConcept< McfClassConcept<GR, int, double>,
+                  NetworkSimplex<GR, int, double> >();
+  }
+
+  // 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), l3(gr), u(gr);
+  Digraph::NodeMap<int> s1(gr), s2(gr), s3(gr), s4(gr), s5(gr), s6(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)
+    .arcMap("low3", l3)
+    .nodeMap("sup1", s1)
+    .nodeMap("sup2", s2)
+    .nodeMap("sup3", s3)
+    .nodeMap("sup4", s4)
+    .nodeMap("sup5", s5)
+    .nodeMap("sup6", s6)
+    .node("source", v)
+    .node("target", w)
+    .run();
+  
+  // Build test digraphs with negative costs
+  Digraph neg_gr;
+  Node n1 = neg_gr.addNode();
+  Node n2 = neg_gr.addNode();
+  Node n3 = neg_gr.addNode();
+  Node n4 = neg_gr.addNode();
+  Node n5 = neg_gr.addNode();
+  Node n6 = neg_gr.addNode();
+  Node n7 = neg_gr.addNode();
+  
+  Arc a1 = neg_gr.addArc(n1, n2);
+  Arc a2 = neg_gr.addArc(n1, n3);
+  Arc a3 = neg_gr.addArc(n2, n4);
+  Arc a4 = neg_gr.addArc(n3, n4);
+  Arc a5 = neg_gr.addArc(n3, n2);
+  Arc a6 = neg_gr.addArc(n5, n3);
+  Arc a7 = neg_gr.addArc(n5, n6);
+  Arc a8 = neg_gr.addArc(n6, n7);
+  Arc a9 = neg_gr.addArc(n7, n5);
+  
+  Digraph::ArcMap<int> neg_c(neg_gr), neg_l1(neg_gr, 0), neg_l2(neg_gr, 0);
+  ConstMap<Arc, int> neg_u1(std::numeric_limits<int>::max()), neg_u2(5000);
+  Digraph::NodeMap<int> neg_s(neg_gr, 0);
+  
+  neg_l2[a7] =  1000;
+  neg_l2[a8] = -1000;
+  
+  neg_s[n1] =  100;
+  neg_s[n4] = -100;
+  
+  neg_c[a1] =  100;
+  neg_c[a2] =   30;
+  neg_c[a3] =   20;
+  neg_c[a4] =   80;
+  neg_c[a5] =   50;
+  neg_c[a6] =   10;
+  neg_c[a7] =   80;
+  neg_c[a8] =   30;
+  neg_c[a9] = -120;
+
+  Digraph negs_gr;
+  Digraph::NodeMap<int> negs_s(negs_gr);
+  Digraph::ArcMap<int> negs_c(negs_gr);
+  ConstMap<Arc, int> negs_l(0), negs_u(1000);
+  n1 = negs_gr.addNode();
+  n2 = negs_gr.addNode();
+  negs_s[n1] = 100;
+  negs_s[n2] = -300;
+  negs_c[negs_gr.addArc(n1, n2)] = -1;
+
+
+  // A. Test NetworkSimplex with the default pivot rule
+  {
+    NetworkSimplex<Digraph> mcf(gr);
+
+    // Check the equality form
+    mcf.upperMap(u).costMap(c);
+    checkMcf(mcf, mcf.supplyMap(s1).run(),
+             gr, l1, u, c, s1, mcf.OPTIMAL, true,   5240, "#A1");
+    checkMcf(mcf, mcf.stSupply(v, w, 27).run(),
+             gr, l1, u, c, s2, mcf.OPTIMAL, true,   7620, "#A2");
+    mcf.lowerMap(l2);
+    checkMcf(mcf, mcf.supplyMap(s1).run(),
+             gr, l2, u, c, s1, mcf.OPTIMAL, true,   5970, "#A3");
+    checkMcf(mcf, mcf.stSupply(v, w, 27).run(),
+             gr, l2, u, c, s2, mcf.OPTIMAL, true,   8010, "#A4");
+    mcf.reset();
+    checkMcf(mcf, mcf.supplyMap(s1).run(),
+             gr, l1, cu, cc, s1, mcf.OPTIMAL, true,   74, "#A5");
+    checkMcf(mcf, mcf.lowerMap(l2).stSupply(v, w, 27).run(),
+             gr, l2, cu, cc, s2, mcf.OPTIMAL, true,   94, "#A6");
+    mcf.reset();
+    checkMcf(mcf, mcf.run(),
+             gr, l1, cu, cc, s3, mcf.OPTIMAL, true,    0, "#A7");
+    checkMcf(mcf, mcf.lowerMap(l2).upperMap(u).run(),
+             gr, l2, u, cc, s3, mcf.INFEASIBLE, false, 0, "#A8");
+    mcf.reset().lowerMap(l3).upperMap(u).costMap(c).supplyMap(s4);
+    checkMcf(mcf, mcf.run(),
+             gr, l3, u, c, s4, mcf.OPTIMAL, true,   6360, "#A9");
+
+    // Check the GEQ form
+    mcf.reset().upperMap(u).costMap(c).supplyMap(s5);
+    checkMcf(mcf, mcf.run(),
+             gr, l1, u, c, s5, mcf.OPTIMAL, true,   3530, "#A10", GEQ);
+    mcf.supplyType(mcf.GEQ);
+    checkMcf(mcf, mcf.lowerMap(l2).run(),
+             gr, l2, u, c, s5, mcf.OPTIMAL, true,   4540, "#A11", GEQ);
+    mcf.supplyMap(s6);
+    checkMcf(mcf, mcf.run(),
+             gr, l2, u, c, s6, mcf.INFEASIBLE, false,  0, "#A12", GEQ);
+
+    // Check the LEQ form
+    mcf.reset().supplyType(mcf.LEQ);
+    mcf.upperMap(u).costMap(c).supplyMap(s6);
+    checkMcf(mcf, mcf.run(),
+             gr, l1, u, c, s6, mcf.OPTIMAL, true,   5080, "#A13", LEQ);
+    checkMcf(mcf, mcf.lowerMap(l2).run(),
+             gr, l2, u, c, s6, mcf.OPTIMAL, true,   5930, "#A14", LEQ);
+    mcf.supplyMap(s5);
+    checkMcf(mcf, mcf.run(),
+             gr, l2, u, c, s5, mcf.INFEASIBLE, false,  0, "#A15", LEQ);
+
+    // Check negative costs
+    NetworkSimplex<Digraph> neg_mcf(neg_gr);
+    neg_mcf.lowerMap(neg_l1).costMap(neg_c).supplyMap(neg_s);
+    checkMcf(neg_mcf, neg_mcf.run(), neg_gr, neg_l1, neg_u1,
+      neg_c, neg_s, neg_mcf.UNBOUNDED, false,    0, "#A16");
+    neg_mcf.upperMap(neg_u2);
+    checkMcf(neg_mcf, neg_mcf.run(), neg_gr, neg_l1, neg_u2,
+      neg_c, neg_s, neg_mcf.OPTIMAL, true,  -40000, "#A17");
+    neg_mcf.reset().lowerMap(neg_l2).costMap(neg_c).supplyMap(neg_s);
+    checkMcf(neg_mcf, neg_mcf.run(), neg_gr, neg_l2, neg_u1,
+      neg_c, neg_s, neg_mcf.UNBOUNDED, false,    0, "#A18");
+      
+    NetworkSimplex<Digraph> negs_mcf(negs_gr);
+    negs_mcf.costMap(negs_c).supplyMap(negs_s);
+    checkMcf(negs_mcf, negs_mcf.run(), negs_gr, negs_l, negs_u,
+      negs_c, negs_s, negs_mcf.OPTIMAL, true, -300, "#A19", GEQ);
+  }
+
+  // B. Test NetworkSimplex with each pivot rule
+  {
+    NetworkSimplex<Digraph> mcf(gr);
+    mcf.supplyMap(s1).costMap(c).upperMap(u).lowerMap(l2);
+
+    checkMcf(mcf, mcf.run(NetworkSimplex<Digraph>::FIRST_ELIGIBLE),
+             gr, l2, u, c, s1, mcf.OPTIMAL, true,   5970, "#B1");
+    checkMcf(mcf, mcf.run(NetworkSimplex<Digraph>::BEST_ELIGIBLE),
+             gr, l2, u, c, s1, mcf.OPTIMAL, true,   5970, "#B2");
+    checkMcf(mcf, mcf.run(NetworkSimplex<Digraph>::BLOCK_SEARCH),
+             gr, l2, u, c, s1, mcf.OPTIMAL, true,   5970, "#B3");
+    checkMcf(mcf, mcf.run(NetworkSimplex<Digraph>::CANDIDATE_LIST),
+             gr, l2, u, c, s1, mcf.OPTIMAL, true,   5970, "#B4");
+    checkMcf(mcf, mcf.run(NetworkSimplex<Digraph>::ALTERING_LIST),
+             gr, l2, u, c, s1, mcf.OPTIMAL, true,   5970, "#B5");
+  }
+
+  return 0;
+}