/* -*- C++ -*-

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

  *

  * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

  * (Egervary Combinatorial Optimization Research Group, 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 <hugo/smart_graph.h>

 #include <hugo/dimacs.h>

 #include <hugo/preflow.h>

 #include <hugo/skeletons/graph.h>

 #include <hugo/skeletons/maps.h>

 using namespace hugo;

 void check_Preflow() 

 {

   typedef int VType;

   typedef skeleton::StaticGraph Graph;

   typedef Graph::Node Node;

   typedef Graph::Edge Edge;

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

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

   typedef skeleton::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.setSource(n);

   preflow_test.setFlow(flow);

   preflow_test.phase1(PType::NO_FLOW);

   preflow_test.minCut(cut);

   preflow_test.phase2();

   preflow_test.setTarget(n);

   preflow_test.setCap(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.tail(e)] && !cut[G.head(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")) + "/preflow_graph.dim";

   }

   else {

     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 mincut(G,false);

   preflow_test.minCut(mincut); 

   int min_cut_value=cut_value(G,mincut,cap);

   CutMap minmincut(G,false);

   preflow_test.minMinCut(minmincut); 

   int min_min_cut_value=cut_value(G,minmincut,cap);

   CutMap maxmincut(G,false);

   preflow_test.maxMinCut(maxmincut); 

   int max_min_cut_value=cut_value(G,maxmincut,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.setCap(cap);  

   preflow_test.phase1(PType::PRE_FLOW);

   CutMap mincut1(G,false);

   preflow_test.minCut(mincut1); 

   min_cut_value=cut_value(G,mincut1,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 mincut2(G,false);

   preflow_test.minCut(mincut2); 

   min_cut_value=cut_value(G,mincut2,cap);

   CutMap minmincut2(G,false);

   preflow_test.minMinCut(minmincut2); 

   min_min_cut_value=cut_value(G,minmincut2,cap);

   preflow_test.maxMinCut(maxmincut); 

   max_min_cut_value=cut_value(G,maxmincut,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.setFlow(flow); 

   NodeIt tmp1(G,s);

   ++tmp1;

   if ( tmp1 != INVALID ) s=tmp1;

   NodeIt tmp2(G,t);

   ++tmp2;

   if ( tmp2 != INVALID ) t=tmp2;

   preflow_test.setSource(s);

   preflow_test.setTarget(t); 

   preflow_test.run();

   CutMap mincut3(G,false);

   preflow_test.minCut(mincut3); 

   min_cut_value=cut_value(G,mincut3,cap);

   CutMap minmincut3(G,false);

   preflow_test.minMinCut(minmincut3); 

   min_min_cut_value=cut_value(G,minmincut3,cap);

   preflow_test.maxMinCut(maxmincut); 

   max_min_cut_value=cut_value(G,maxmincut,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.");

 }