/* -*- C++ -*-

  * test/preflow_test.cc - Part of LEMON, a generic C++ optimization library

  *

  * Copyright (C) 2006 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 <fstream>

 #include <string>

 #include "test_tools.h"

 #include <lemon/smart_graph.h>

 #include <lemon/dimacs.h>

 #include <lemon/preflow.h>

 #include <lemon/concept/graph.h>

 #include <lemon/concept/maps.h>

 using namespace lemon;

 void check_Preflow() 

 {

   typedef int VType;

   typedef concept::StaticGraph Graph;

   typedef Graph::Node Node;

   typedef Graph::Edge Edge;

   typedef concept::ReadMap<Edge,VType> CapMap;

   typedef concept::ReadWriteMap<Edge,VType> FlowMap;

   typedef concept::ReadWriteMap<Node,bool> CutMap;

   typedef Preflow<Graph, int, CapMap, FlowMap> PType;

   Graph g;

   Node n;

   CapMap cap;

   FlowMap flow;

   CutMap cut;

   PType preflow_test(g,n,n,cap,flow);

   preflow_test.run();

   preflow_test.flowValue();

   preflow_test.source(n);

   preflow_test.flowMap(flow);

   preflow_test.phase1(PType::NO_FLOW);

   preflow_test.minCut(cut);

   preflow_test.phase2();

   preflow_test.target(n);

   preflow_test.capacityMap(cap);

   preflow_test.minMinCut(cut);

   preflow_test.maxMinCut(cut);

 }

 int cut_value ( SmartGraph& g, SmartGraph::NodeMap<bool>& cut, 

 		SmartGraph::EdgeMap<int>& cap) {

   int c=0;

   for(SmartGraph::EdgeIt e(g); e!=INVALID; ++e) {

     if (cut[g.source(e)] && !cut[g.target(e)]) c+=cap[e];

   }

   return c;

 }

 int main() {

   typedef SmartGraph Graph;

   typedef Graph::Node Node;

   typedef Graph::NodeIt NodeIt;

   typedef Graph::EdgeIt EdgeIt;

   typedef Graph::EdgeMap<int> CapMap;

   typedef Graph::EdgeMap<int> FlowMap;

   typedef Graph::NodeMap<bool> CutMap;

   typedef Preflow<Graph, int> PType;

   std::string f_name;

   if( getenv("srcdir") )

     f_name = std::string(getenv("srcdir"));

   else f_name = ".";

   f_name += "/preflow_graph.dim";

   std::ifstream file(f_name.c_str());

   check(file, "Input file '" << f_name << "' not found.");

   Graph g;

   Node s, t;

   CapMap cap(g);

   readDimacs(file, g, cap, s, t);

   FlowMap flow(g,0);

   PType preflow_test(g, s, t, cap, flow);

   preflow_test.run(PType::ZERO_FLOW);

   CutMap min_cut(g,false);

   preflow_test.minCut(min_cut); 

   int min_cut_value=cut_value(g,min_cut,cap);

   CutMap min_min_cut(g,false);

   preflow_test.minMinCut(min_min_cut); 

   int min_min_cut_value=cut_value(g,min_min_cut,cap);

   CutMap max_min_cut(g,false);

   preflow_test.maxMinCut(max_min_cut); 

   int max_min_cut_value=cut_value(g,max_min_cut,cap);

   check(preflow_test.flowValue() == min_cut_value &&

 	min_cut_value == min_min_cut_value &&

 	min_min_cut_value == max_min_cut_value,

 	"The max flow value is not equal to the three min cut values.");

   int flow_value=preflow_test.flowValue();

   for(EdgeIt e(g); e!=INVALID; ++e) cap[e]=2*cap[e]; 

   preflow_test.capacityMap(cap);  

   preflow_test.phase1(PType::PRE_FLOW);

   CutMap min_cut1(g,false);

   preflow_test.minCut(min_cut1); 

   min_cut_value=cut_value(g,min_cut1,cap);

   check(preflow_test.flowValue() == min_cut_value &&

 	min_cut_value == 2*flow_value,

 	"The max flow value or the min cut value is wrong.");

   preflow_test.phase2();

   CutMap min_cut2(g,false);

   preflow_test.minCut(min_cut2); 

   min_cut_value=cut_value(g,min_cut2,cap);

   CutMap min_min_cut2(g,false);

   preflow_test.minMinCut(min_min_cut2); 

   min_min_cut_value=cut_value(g,min_min_cut2,cap);

   preflow_test.maxMinCut(max_min_cut); 

   max_min_cut_value=cut_value(g,max_min_cut,cap);

   check(preflow_test.flowValue() == min_cut_value &&

 	min_cut_value == min_min_cut_value &&

 	min_min_cut_value == max_min_cut_value &&

 	min_cut_value == 2*flow_value,

 	"The max flow value or the three min cut values were not doubled");

   EdgeIt e(g);

   for( int i=1; i==10; ++i ) {

     flow.set(e,0);

     ++e;

   }

   preflow_test.flowMap(flow); 

   NodeIt tmp1(g,s);

   ++tmp1;

   if ( tmp1 != INVALID ) s=tmp1;

   NodeIt tmp2(g,t);

   ++tmp2;

   if ( tmp2 != INVALID ) t=tmp2;

   preflow_test.source(s);

   preflow_test.target(t); 

   preflow_test.run();

   CutMap min_cut3(g,false);

   preflow_test.minCut(min_cut3); 

   min_cut_value=cut_value(g,min_cut3,cap);

   CutMap min_min_cut3(g,false);

   preflow_test.minMinCut(min_min_cut3); 

   min_min_cut_value=cut_value(g,min_min_cut3,cap);

   preflow_test.maxMinCut(max_min_cut); 

   max_min_cut_value=cut_value(g,max_min_cut,cap);

   check(preflow_test.flowValue() == min_cut_value &&

 	min_cut_value == min_min_cut_value &&

 	min_min_cut_value == max_min_cut_value,

 	"The max flow value or the three min cut values are incorrect.");

 }