# HG changeset patch
# User athos
# Date 1084292118 0
# Node ID 4ce8c695e748847126567bb62c3282959d97995b
# Parent  0566ac97809bc6a7d228dfe0d7c5fdfff70cee69
Sorry, the other half of the move comes here.

diff -r 0566ac97809b -r 4ce8c695e748 src/hugo/mincostflows.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hugo/mincostflows.h	Tue May 11 16:15:18 2004 +0000
@@ -0,0 +1,254 @@
+// -*- c++ -*-
+#ifndef HUGO_MINCOSTFLOWS_H
+#define HUGO_MINCOSTFLOWS_H
+
+///\ingroup galgs
+///\file
+///\brief An algorithm for finding a flow of value \c k (for small values of \c k) having minimal total cost 
+
+#include <iostream>
+#include <hugo/dijkstra.h>
+#include <hugo/graph_wrapper.h>
+#include <hugo/maps.h>
+#include <vector>
+#include <for_each_macros.h>
+
+namespace hugo {
+
+/// \addtogroup galgs
+/// @{
+
+  ///\brief Implementation of an algorithm for finding a flow of value \c k 
+  ///(for small values of \c k) having minimal total cost between 2 nodes 
+  /// 
+  ///
+  /// The class \ref hugo::MinCostFlows "MinCostFlows" implements
+  /// an algorithm for finding a flow of value \c k 
+  ///(for small values of \c k) having minimal total cost  
+  /// from a given source node to a given target node in an
+  /// edge-weighted directed graph having nonnegative integer capacities.
+  /// The range of the length (weight) function is nonnegative reals but 
+  /// the range of capacity function is the set of nonnegative integers. 
+  /// It is not a polinomial time algorithm for counting the minimum cost
+  /// maximal flow, since it counts the minimum cost flow for every value 0..M
+  /// where \c M is the value of the maximal flow.
+  ///
+  ///\author Attila Bernath
+  template <typename Graph, typename LengthMap, typename CapacityMap>
+  class MinCostFlows {
+
+    typedef typename LengthMap::ValueType Length;
+
+    //Warning: this should be integer type
+    typedef typename CapacityMap::ValueType Capacity;
+    
+    typedef typename Graph::Node Node;
+    typedef typename Graph::NodeIt NodeIt;
+    typedef typename Graph::Edge Edge;
+    typedef typename Graph::OutEdgeIt OutEdgeIt;
+    typedef typename Graph::template EdgeMap<int> EdgeIntMap;
+
+    //    typedef ConstMap<Edge,int> ConstMap;
+
+    typedef ResGraphWrapper<const Graph,int,CapacityMap,EdgeIntMap> ResGraphType;
+    typedef typename ResGraphType::Edge ResGraphEdge;
+
+    class ModLengthMap {   
+      //typedef typename ResGraphType::template NodeMap<Length> NodeMap;
+      typedef typename Graph::template NodeMap<Length> NodeMap;
+      const ResGraphType& G;
+      //      const EdgeIntMap& rev;
+      const LengthMap &ol;
+      const NodeMap &pot;
+    public :
+      typedef typename LengthMap::KeyType KeyType;
+      typedef typename LengthMap::ValueType ValueType;
+	
+      ValueType operator[](typename ResGraphType::Edge e) const {     
+	if (G.forward(e))
+	  return  ol[e]-(pot[G.head(e)]-pot[G.tail(e)]);   
+	else
+	  return -ol[e]-(pot[G.head(e)]-pot[G.tail(e)]);   
+      }     
+	
+      ModLengthMap(const ResGraphType& _G,
+		   const LengthMap &o,  const NodeMap &p) : 
+	G(_G), /*rev(_rev),*/ ol(o), pot(p){}; 
+    };//ModLengthMap
+
+
+  protected:
+    
+    //Input
+    const Graph& G;
+    const LengthMap& length;
+    const CapacityMap& capacity;
+
+
+    //auxiliary variables
+
+    //To store the flow
+    EdgeIntMap flow; 
+    //To store the potentila (dual variables)
+    typename Graph::template NodeMap<Length> potential;
+    
+    //Container to store found paths
+    //std::vector< std::vector<Edge> > paths;
+    //typedef DirPath<Graph> DPath;
+    //DPath paths;
+
+
+    Length total_length;
+
+
+  public :
+
+
+    MinCostFlows(Graph& _G, LengthMap& _length, CapacityMap& _cap) : G(_G), 
+      length(_length), capacity(_cap), flow(_G), potential(_G){ }
+
+    
+    ///Runs the algorithm.
+
+    ///Runs the algorithm.
+    ///Returns k if there are at least k edge-disjoint paths from s to t.
+    ///Otherwise it returns the number of found edge-disjoint paths from s to t.
+    ///\todo May be it does make sense to be able to start with a nonzero 
+    /// feasible primal-dual solution pair as well.
+    int run(Node s, Node t, int k) {
+
+      //Resetting variables from previous runs
+      total_length = 0;
+      
+      FOR_EACH_LOC(typename Graph::EdgeIt, e, G){
+	flow.set(e,0);
+      }
+      
+      FOR_EACH_LOC(typename Graph::NodeIt, n, G){
+	//cout << potential[n]<<endl;
+	potential.set(n,0);
+      }
+      
+
+      
+      //We need a residual graph
+      ResGraphType res_graph(G, capacity, flow);
+
+      //Initialize the copy of the Dijkstra potential to zero
+      
+      //typename ResGraphType::template NodeMap<Length> potential(res_graph);
+
+
+      ModLengthMap mod_length(res_graph, length, potential);
+
+      Dijkstra<ResGraphType, ModLengthMap> dijkstra(res_graph, mod_length);
+
+      int i;
+      for (i=0; i<k; ++i){
+	dijkstra.run(s);
+	if (!dijkstra.reached(t)){
+	  //There are no k paths from s to t
+	  break;
+	};
+	
+	{
+	  //We have to copy the potential
+	  typename ResGraphType::NodeIt n;
+	  for ( res_graph.first(n) ; res_graph.valid(n) ; res_graph.next(n) ) {
+	      potential[n] += dijkstra.distMap()[n];
+	  }
+	}
+
+
+	//Augmenting on the sortest path
+	Node n=t;
+	ResGraphEdge e;
+	while (n!=s){
+	  e = dijkstra.pred(n);
+	  n = dijkstra.predNode(n);
+	  res_graph.augment(e,1);
+	  //Let's update the total length
+	  if (res_graph.forward(e))
+	    total_length += length[e];
+	  else 
+	    total_length -= length[e];	    
+	}
+
+	  
+      }
+      
+
+      return i;
+    }
+
+
+
+
+    ///This function gives back the total length of the found paths.
+    ///Assumes that \c run() has been run and nothing changed since then.
+    Length totalLength(){
+      return total_length;
+    }
+
+    ///Returns a const reference to the EdgeMap \c flow. \pre \ref run() must
+    ///be called before using this function.
+    const EdgeIntMap &getFlow() const { return flow;}
+
+  ///Returns a const reference to the NodeMap \c potential (the dual solution).
+    /// \pre \ref run() must be called before using this function.
+    const EdgeIntMap &getPotential() const { return potential;}
+
+    ///This function checks, whether the given solution is optimal
+    ///Running after a \c run() should return with true
+    ///In this "state of the art" this only check optimality, doesn't bother with feasibility
+    ///
+    ///\todo Is this OK here?
+    bool checkComplementarySlackness(){
+      Length mod_pot;
+      Length fl_e;
+      FOR_EACH_LOC(typename Graph::EdgeIt, e, G){
+	//C^{\Pi}_{i,j}
+	mod_pot = length[e]-potential[G.head(e)]+potential[G.tail(e)];
+	fl_e = flow[e];
+	//	std::cout << fl_e << std::endl;
+	if (0<fl_e && fl_e<capacity[e]){
+	  if (mod_pot != 0)
+	    return false;
+	}
+	else{
+	  if (mod_pot > 0 && fl_e != 0)
+	    return false;
+	  if (mod_pot < 0 && fl_e != capacity[e])
+	    return false;
+	}
+      }
+      return true;
+    }
+    
+    /*
+      ///\todo To be implemented later
+
+    ///This function gives back the \c j-th path in argument p.
+    ///Assumes that \c run() has been run and nothing changed since then.
+    /// \warning It is assumed that \c p is constructed to be a path of graph \c G. If \c j is greater than the result of previous \c run, then the result here will be an empty path.
+    template<typename DirPath>
+    void getPath(DirPath& p, int j){
+      p.clear();
+      typename DirPath::Builder B(p);
+      for(typename std::vector<Edge>::iterator i=paths[j].begin(); 
+	  i!=paths[j].end(); ++i ){
+	B.pushBack(*i);
+      }
+
+      B.commit();
+    }
+
+    */
+
+  }; //class MinCostFlows
+
+  ///@}
+
+} //namespace hugo
+
+#endif //HUGO_MINCOSTFLOW_H
diff -r 0566ac97809b -r 4ce8c695e748 src/hugo/minlengthpaths.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hugo/minlengthpaths.h	Tue May 11 16:15:18 2004 +0000
@@ -0,0 +1,164 @@
+// -*- c++ -*-
+#ifndef HUGO_MINLENGTHPATHS_H
+#define HUGO_MINLENGTHPATHS_H
+
+///\ingroup galgs
+///\file
+///\brief An algorithm for finding k paths of minimal total length.
+
+#include <iostream>
+//#include <hugo/dijkstra.h>
+//#include <hugo/graph_wrapper.h>
+#include <hugo/maps.h>
+#include <vector>
+#include <hugo/mincostflows.h>
+#include <for_each_macros.h>
+
+namespace hugo {
+
+/// \addtogroup galgs
+/// @{
+
+  ///\brief Implementation of an algorithm for finding k paths between 2 nodes 
+  /// of minimal total length 
+  ///
+  /// The class \ref hugo::MinLengthPaths "MinLengthPaths" implements
+  /// an algorithm for finding k edge-disjoint paths
+  /// from a given source node to a given target node in an
+  /// edge-weighted directed graph having minimal total weigth (length).
+  ///
+  ///\warning It is assumed that the lengths are positive, since the
+  /// general flow-decomposition is not implemented yet.
+  ///
+  ///\author Attila Bernath
+  template <typename Graph, typename LengthMap>
+  class MinLengthPaths{
+
+
+    typedef typename LengthMap::ValueType Length;
+    
+    typedef typename Graph::Node Node;
+    typedef typename Graph::NodeIt NodeIt;
+    typedef typename Graph::Edge Edge;
+    typedef typename Graph::OutEdgeIt OutEdgeIt;
+    typedef typename Graph::template EdgeMap<int> EdgeIntMap;
+
+    typedef ConstMap<Edge,int> ConstMap;
+
+    //Input
+    const Graph& G;
+
+    //Auxiliary variables
+    //This is the capacity map for the mincostflow problem
+    ConstMap const1map;
+    //This MinCostFlows instance will actually solve the problem
+    MinCostFlows<Graph, LengthMap, ConstMap> mincost_flow;
+
+    //Container to store found paths
+    std::vector< std::vector<Edge> > paths;
+
+  public :
+
+
+    MinLengthPaths(Graph& _G, LengthMap& _length) : G(_G),
+      const1map(1), mincost_flow(_G, _length, const1map){}
+
+    ///Runs the algorithm.
+
+    ///Runs the algorithm.
+    ///Returns k if there are at least k edge-disjoint paths from s to t.
+   ///Otherwise it returns the number of found edge-disjoint paths from s to t.
+    int run(Node s, Node t, int k) {
+
+      int i = mincost_flow.run(s,t,k);
+      
+
+
+      //Let's find the paths
+      //We put the paths into stl vectors (as an inner representation). 
+      //In the meantime we lose the information stored in 'reversed'.
+      //We suppose the lengths to be positive now.
+
+      //We don't want to change the flow of mincost_flow, so we make a copy
+      //The name here suggests that the flow has only 0/1 values.
+      EdgeIntMap reversed(G); 
+
+      FOR_EACH_LOC(typename Graph::EdgeIt, e, G){
+	reversed[e] = mincost_flow.getFlow()[e];
+      }
+      
+      paths.clear();
+      //total_length=0;
+      paths.resize(k);
+      for (int j=0; j<i; ++j){
+	Node n=s;
+	OutEdgeIt e;
+
+	while (n!=t){
+
+
+	  G.first(e,n);
+	  
+	  while (!reversed[e]){
+	    G.next(e);
+	  }
+	  n = G.head(e);
+	  paths[j].push_back(e);
+	  //total_length += length[e];
+	  reversed[e] = 1-reversed[e];
+	}
+	
+      }
+      return i;
+    }
+
+    
+    ///This function gives back the total length of the found paths.
+    ///Assumes that \c run() has been run and nothing changed since then.
+    Length totalLength(){
+      return mincost_flow.totalLength();
+    }
+
+    ///Returns a const reference to the EdgeMap \c flow. \pre \ref run() must
+    ///be called before using this function.
+    const EdgeIntMap &getFlow() const { return mincost_flow.flow;}
+
+  ///Returns a const reference to the NodeMap \c potential (the dual solution).
+    /// \pre \ref run() must be called before using this function.
+    const EdgeIntMap &getPotential() const { return mincost_flow.potential;}
+
+    ///This function checks, whether the given solution is optimal
+    ///Running after a \c run() should return with true
+    ///In this "state of the art" this only checks optimality, doesn't bother with feasibility
+    ///
+    ///\todo Is this OK here?
+    bool checkComplementarySlackness(){
+      return mincost_flow.checkComplementarySlackness();
+    }
+
+    ///This function gives back the \c j-th path in argument p.
+    ///Assumes that \c run() has been run and nothing changed since then.
+    /// \warning It is assumed that \c p is constructed to be a path of graph \c G. If \c j is not less than the result of previous \c run, then the result here will be an empty path (\c j can be 0 as well).
+    template<typename DirPath>
+    void getPath(DirPath& p, size_t j){
+      
+      p.clear();
+      if (j>paths.size()-1){
+	return;
+      }
+      typename DirPath::Builder B(p);
+      for(typename std::vector<Edge>::iterator i=paths[j].begin(); 
+	  i!=paths[j].end(); ++i ){
+	B.pushBack(*i);
+      }
+
+      B.commit();
+    }
+
+  }; //class MinLengthPaths
+
+  ///@}
+
+} //namespace hugo
+
+#endif //HUGO_MINLENGTHPATHS_H
diff -r 0566ac97809b -r 4ce8c695e748 src/test/minlengthpaths_test.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/test/minlengthpaths_test.cc	Tue May 11 16:15:18 2004 +0000
@@ -0,0 +1,99 @@
+#include <iostream>
+#include <hugo/list_graph.h>
+#include <hugo/minlengthpaths.h>
+#include <path.h>
+
+using namespace std;
+using namespace hugo;
+
+
+
+bool passed = true;
+
+void check(bool rc, char *msg="") {
+  passed = passed && rc;
+  if(!rc) {
+    std::cerr << "Test failed! ("<< msg << ")" << std::endl; \
+ 
+
+  }
+}
+
+
+
+int main()
+{
+
+  typedef ListGraph::Node Node;
+  typedef ListGraph::Edge Edge;
+
+  ListGraph graph;
+
+  //Ahuja könyv példája
+
+  Node s=graph.addNode();
+  Node v1=graph.addNode();  
+  Node v2=graph.addNode();
+  Node v3=graph.addNode();
+  Node v4=graph.addNode();
+  Node v5=graph.addNode();
+  Node t=graph.addNode();
+
+  Edge s_v1=graph.addEdge(s, v1);
+  Edge v1_v2=graph.addEdge(v1, v2);
+  Edge s_v3=graph.addEdge(s, v3);
+  Edge v2_v4=graph.addEdge(v2, v4);
+  Edge v2_v5=graph.addEdge(v2, v5);
+  Edge v3_v5=graph.addEdge(v3, v5);
+  Edge v4_t=graph.addEdge(v4, t);
+  Edge v5_t=graph.addEdge(v5, t);
+  
+
+  ListGraph::EdgeMap<int> length(graph);
+
+  length.set(s_v1, 6);
+  length.set(v1_v2, 4);
+  length.set(s_v3, 10);
+  length.set(v2_v4, 5);
+  length.set(v2_v5, 1);
+  length.set(v3_v5, 5);
+  length.set(v4_t, 8);
+  length.set(v5_t, 8);
+
+  std::cout << "Minlengthpaths algorithm test..." << std::endl;
+
+  
+  int k=3;
+  MinLengthPaths< ListGraph, ListGraph::EdgeMap<int> >
+    surb_test(graph, length);
+
+  check(  surb_test.run(s,t,k) == 2 && surb_test.totalLength() == 46,"Two paths, total length should be 46");
+
+  check(  surb_test.checkComplementarySlackness(), "Complementary slackness conditions are not met.");
+
+  typedef DirPath<ListGraph> DPath;
+  DPath P(graph);
+
+  /*
+  surb_test.getPath(P,0);
+  check(P.length() == 4, "First path should contain 4 edges.");  
+  cout<<P.length()<<endl;
+  surb_test.getPath(P,1);
+  check(P.length() == 3, "Second path: 3 edges.");
+  cout<<P.length()<<endl;
+  */  
+
+  k=1;
+  check(  surb_test.run(s,t,k) == 1 && surb_test.totalLength() == 19,"One path, total length should be 19");
+
+  check(  surb_test.checkComplementarySlackness(), "Complementary slackness conditions are not met.");
+ 
+  surb_test.getPath(P,0);
+  check(P.length() == 4, "First path should contain 4 edges.");  
+
+  cout << (passed ? "All tests passed." : "Some of the tests failed!!!")
+       << endl;
+
+  return passed ? 0 : 1;
+
+}