marci@43: #ifndef MARCI_MAX_FLOW_HH
marci@43: #define MARCI_MAX_FLOW_HH
marci@43: 
marci@43: #include <algorithm>
marci@43: 
marci@43: #include <bfs_iterator.hh>
marci@43: 
marci@43: namespace marci {
marci@43: 
marci@43:   template<typename Graph, typename T>
marci@43:   class ResGraph {
marci@43:     typedef typename Graph::NodeIt NodeIt;
marci@43:     typedef typename Graph::EachNodeIt EachNodeIt;
marci@43:     typedef typename Graph::SymEdgeIt OldSymEdgeIt;
marci@43:     const Graph& G;
marci@43:     typename Graph::EdgeMap<T>& flow;
marci@43:     const typename Graph::EdgeMap<T>& capacity;
marci@43:   public:
marci@43:     ResGraph(const Graph& _G, typename Graph::EdgeMap<T>& _flow, 
marci@43: 	     const typename Graph::EdgeMap<T>& _capacity) : 
marci@43:       G(_G), flow(_flow), capacity(_capacity) { }
marci@43: 
marci@43:     class EdgeIt; 
marci@43:     class OutEdgeIt; 
marci@43:     friend class EdgeIt; 
marci@43:     friend class OutEdgeIt; 
marci@43: 
marci@43:     class EdgeIt {
marci@43:       friend class ResGraph<Graph, T>;
marci@43:     protected:
marci@43:       const ResGraph<Graph, T>* resG;
marci@43:       OldSymEdgeIt sym;
marci@43:     public:
marci@43:       EdgeIt() { } 
marci@43:       //EdgeIt(const EdgeIt& e) : resG(e.resG), sym(e.sym) { }
marci@43:       T free() const { 
marci@43: 	if (resG->G.aNode(sym)==resG->G.tail(sym)) { 
marci@43: 	  return (resG->capacity.get(sym)-resG->flow.get(sym)); 
marci@43: 	} else { 
marci@43: 	  return (resG->flow.get(sym)); 
marci@43: 	}
marci@43:       }
marci@43:       bool valid() const { return sym.valid(); }
marci@43:       void augment(const T a) const {
marci@43: 	if (resG->G.aNode(sym)==resG->G.tail(sym)) { 
marci@43: 	  resG->flow.set(sym, resG->flow.get(sym)+a);
marci@43: 	} else { 
marci@43: 	  resG->flow.set(sym, resG->flow.get(sym)-a);
marci@43: 	}
marci@43:       }
marci@43:     };
marci@43: 
marci@43:     class OutEdgeIt : public EdgeIt {
marci@43:       friend class ResGraph<Graph, T>;
marci@43:     public:
marci@43:       OutEdgeIt() { }
marci@43:       //OutEdgeIt(const OutEdgeIt& e) { resG=e.resG; sym=e.sym; }
marci@43:     private:
marci@43:       OutEdgeIt(const ResGraph<Graph, T>& _resG, const NodeIt v) { 
marci@43:       	resG=&_resG;
marci@43: 	sym=resG->G.template first<OldSymEdgeIt>(v);
marci@43: 	while( sym.valid() && !(free()>0) ) { ++sym; }
marci@43:       }
marci@43:     public:
marci@43:       OutEdgeIt& operator++() { 
marci@43: 	++sym; 
marci@43: 	while( sym.valid() && !(free()>0) ) { ++sym; }
marci@43: 	return *this; 
marci@43:       }
marci@43:     };
marci@43: 
marci@43:     void getFirst(OutEdgeIt& e, const NodeIt v) const { 
marci@43:       e=OutEdgeIt(*this, v); 
marci@43:     }
marci@43:     void getFirst(EachNodeIt& v) const { G.getFirst(v); }
marci@43:     
marci@43:     template< typename It >
marci@43:     It first() const { 
marci@43:       It e;
marci@43:       getFirst(e);
marci@43:       return e; 
marci@43:     }
marci@43: 
marci@43:     template< typename It >
marci@43:     It first(const NodeIt v) const { 
marci@43:       It e;
marci@43:       getFirst(e, v);
marci@43:       return e; 
marci@43:     }
marci@43: 
marci@43:     NodeIt tail(const EdgeIt e) const { return G.aNode(e.sym); }
marci@43:     NodeIt head(const EdgeIt e) const { return G.bNode(e.sym); }
marci@43: 
marci@43:     NodeIt aNode(const OutEdgeIt e) const { return G.aNode(e.sym); }
marci@43:     NodeIt bNode(const OutEdgeIt e) const { return G.bNode(e.sym); }
marci@43: 
marci@43:     int id(const NodeIt v) const { return G.id(v); }
marci@43: 
marci@43:     template <typename ValueType>
marci@43:     class NodeMap {
marci@43:       //const ResGraph<Graph, T>& G; 
marci@43:       typename Graph::NodeMap<ValueType> node_map; 
marci@43:     public:
marci@43:       NodeMap(const ResGraph<Graph, T>& _G) : node_map(_G.G)/*: G(_G)*/ { }
marci@43:       NodeMap(const ResGraph<Graph, T>& _G, const ValueType a) : node_map(_G.G, a) /*: G(_G)*/ { }
marci@43:       void set(const NodeIt nit, const ValueType a) { node_map.set(nit, a); }
marci@43:       ValueType get(const NodeIt nit) const { return node_map.get(nit); }
marci@43:     };
marci@43: 
marci@43:   };
marci@43: 
marci@43:   template <typename Graph, typename T>
marci@43:   struct max_flow_type {
marci@43:     typedef typename Graph::NodeIt NodeIt;
marci@43:     typedef typename Graph::EdgeIt EdgeIt;
marci@43:     typedef typename Graph::EachEdgeIt EachEdgeIt;
marci@43:     typedef typename Graph::OutEdgeIt OutEdgeIt;
marci@43:     typedef typename Graph::InEdgeIt InEdgeIt;
marci@43:     const Graph& G;
marci@43:     NodeIt s;
marci@43:     NodeIt t;
marci@43:     typename Graph::EdgeMap<T> flow;
marci@43:     const typename Graph::EdgeMap<T>& capacity;
marci@43: 
marci@43:     max_flow_type(const Graph& _G, NodeIt _s, NodeIt _t, const typename Graph::EdgeMap<T>& _capacity) : G(_G), s(_s), t(_t), flow(_G, 0), capacity(_capacity) { }
marci@43:     void run() {
marci@43:       typedef ResGraph<Graph, T> AugGraph;
marci@43:       AugGraph res_graph(G, flow, capacity);
marci@43: 
marci@43:       bool augment;
marci@43:       do {
marci@43: 	augment=false;
marci@43: 
marci@43: 	typedef typename AugGraph::OutEdgeIt AugOutEdgeIt;
marci@43: 	typedef typename AugGraph::EdgeIt AugEdgeIt;
marci@43: 	typedef std::queue<AugOutEdgeIt> BfsQueue;
marci@43: 	BfsQueue bfs_queue;
marci@43: 	bfs_queue.push(res_graph.template first<AugOutEdgeIt>(s));
marci@43: 
marci@43: 	typedef typename AugGraph::NodeMap<bool> ReachedMap;
marci@43: 	ReachedMap reached(res_graph, false);
marci@43: 	reached.set(s, true); 
marci@43: 	
marci@43: 	bfs_iterator1< AugGraph, ReachedMap > 
marci@43: 	res_bfs(res_graph, bfs_queue, reached);
marci@43: 
marci@43: 	typedef typename AugGraph::NodeMap<AugEdgeIt> PredMap;
marci@43: 	PredMap pred(res_graph);
marci@43: 	//typename AugGraph::EdgeIt a; //invalid
marci@43: 	//a.makeInvalid();
marci@43: 	//pred.set(s, a);
marci@43: 
marci@43: 	typedef typename AugGraph::NodeMap<int> FreeMap;
marci@43: 	FreeMap free(res_graph);
marci@43: 	
marci@43: 	//searching for augmenting path
marci@43: 	while ( res_bfs.valid() ) { 
marci@43: 	  //std::cout<<"KULSO ciklus itt jar: "<<G.id(res_graph.tail(res_bfs))<<"->"<<G.id(res_graph.head(res_bfs))<<std::endl;
marci@43: 	  if (res_bfs.newly_reached()) {
marci@43: 	    AugOutEdgeIt e=AugOutEdgeIt(res_bfs);
marci@43: 	    NodeIt v=res_graph.tail(e);
marci@43: 	    NodeIt w=res_graph.head(e);
marci@43: 	    //std::cout<<G.id(v)<<"->"<<G.id(w)<<", "<<G.id(w)<<" is newly reached";
marci@43: 	    pred.set(w, e);
marci@43: 	    if (pred.get(v).valid()) {
marci@43: 	      free.set(w, std::min(free.get(v), e.free()));
marci@43: 	      //std::cout <<" nem elso csucs: ";
marci@43: 	      //std::cout <<"szabad kap eddig: "<< free.get(w) << " ";
marci@43: 	    } else {
marci@43: 	      free.set(w, e.free()); 
marci@43: 	      //std::cout <<" elso csucs: ";
marci@43: 	      //std::cout <<"szabad kap eddig: "<< free.get(w) << " ";
marci@43: 	    }
marci@43: 	    //std::cout<<std::endl;
marci@43: 	  }
marci@43: 	
marci@43: 	  if (res_graph.head(res_bfs)==t) break;
marci@43: 	  ++res_bfs;
marci@43: 	} //end searching augmenting path
marci@43: 	if (reached.get(t)) {
marci@43: 	  augment=true;
marci@43: 	  NodeIt n=t;
marci@43: 	  T augment_value=free.get(t);
marci@43: 	  std::cout<<"augmentation: ";
marci@43: 	  while (pred.get(n).valid()) { 
marci@43: 	    AugEdgeIt e=pred.get(n);
marci@43: 	    e.augment(augment_value); 
marci@43: 	    std::cout<<"("<<res_graph.tail(e)<< "->"<<res_graph.head(e)<<") ";
marci@43: 	    n=res_graph.tail(e);
marci@43: 	  }
marci@43: 	  std::cout<<std::endl;
marci@43: 	}
marci@43: 
marci@43: 	std::cout << "actual flow: "<< std::endl;
marci@43: 	for(EachEdgeIt e=G.template first<EachEdgeIt>(); e.valid(); ++e) { 
marci@43: 	  std::cout<<"("<<G.tail(e)<< "-"<<flow.get(e)<<"->"<<G.head(e)<<") ";
marci@43: 	}
marci@43: 	std::cout<<std::endl;
marci@43: 
marci@43:       } while (augment);
marci@43:     }
marci@43:   };
marci@43: 
marci@43: } // namespace marci
marci@43: 
marci@43: #endif //MARCI_MAX_FLOW_HH