marci@9: #ifndef MARCI_MAX_FLOW_HH
marci@9: #define MARCI_MAX_FLOW_HH
marci@9: 
marci@9: #include <algorithm>
marci@9: 
marci@9: #include <marci_property_vector.hh>
marci@9: #include <marci_bfs.hh>
marci@9: 
marci@9: namespace marci {
marci@9: 
marci@9:   template<typename graph_type, typename T>
marci@9:   class res_graph_type { 
marci@19:     typedef typename graph_type::node_iterator node_iterator;
marci@19:     typedef typename graph_type::each_node_iterator each_node_iterator;
marci@19:     typedef typename graph_type::sym_edge_iterator old_sym_edge_iterator;
marci@9:     graph_type& G;
marci@9:     edge_property_vector<graph_type, T>& flow;
marci@9:     edge_property_vector<graph_type, T>& capacity;
marci@9:   public:
marci@9:     res_graph_type(graph_type& _G, edge_property_vector<graph_type, T>& _flow, edge_property_vector<graph_type, T>& _capacity) : G(_G), flow(_flow), capacity(_capacity) { }
marci@9: 
marci@19:     class edge_iterator {
marci@9:       friend class res_graph_type<graph_type, T>;
marci@9:     protected:
marci@9:       res_graph_type<graph_type, T>* resG;
marci@19:       old_sym_edge_iterator sym;
marci@9:     public:
marci@19:       edge_iterator() { }
marci@9:       //bool is_free() {  
marci@9:       //if (resG->G.a_node(sym)==resG->G.tail(sym)) { 
marci@9:       //  return (resG->flow.get(sym)<resG->capacity.get(sym)); 
marci@9:       //} else { 
marci@9:       //  return (resG->flow.get(sym)>0); 
marci@9:       //}
marci@9:       //}
marci@9:       T free() { 
marci@9: 	if (resG->G.a_node(sym)==resG->G.tail(sym)) { 
marci@9: 	  return (resG->capacity.get(sym)-resG->flow.get(sym)); 
marci@9: 	} else { 
marci@9: 	  return (resG->flow.get(sym)); 
marci@9: 	}
marci@9:       }
marci@19:       bool valid() { return sym.valid(); }
marci@17:       void make_invalid() { sym.make_invalid(); }
marci@9:       void augment(T a) {
marci@9: 	if (resG->G.a_node(sym)==resG->G.tail(sym)) { 
marci@9: 	  resG->flow.put(sym, resG->flow.get(sym)+a);
marci@9: 	} else { 
marci@9: 	  resG->flow.put(sym, resG->flow.get(sym)-a);
marci@9: 	}
marci@9:       }
marci@9:     };
marci@9: 
marci@19:     class out_edge_iterator : public edge_iterator {
marci@9:     public:
marci@19:       out_edge_iterator() { }
marci@19:       out_edge_iterator(res_graph_type<graph_type, T>& _resG, const node_iterator& v) { 
marci@9:       	resG=&_resG;
marci@9: 	sym=resG->G.first_sym_edge(v);
marci@19: 	while( sym.valid() && !(free()>0) ) { ++sym; }
marci@9:       }
marci@19:       out_edge_iterator& operator++() { 
marci@9: 	++sym; 
marci@19: 	while( sym.valid() && !(free()>0) ) { ++sym; }
marci@9: 	return *this; 
marci@9:       }
marci@9:     };
marci@9: 
marci@19:     out_edge_iterator first_out_edge(const node_iterator& v) {
marci@19:       return out_edge_iterator(*this, v);
marci@9:     }
marci@9: 
marci@9:     each_node_iterator first_node() {
marci@9:       return G.first_node();
marci@9:     }
marci@9: 
marci@19:     node_iterator tail(const edge_iterator& e) { return G.a_node(e.sym); }
marci@19:     node_iterator head(const edge_iterator& e) { return G.b_node(e.sym); }
marci@9: 
marci@9:     int id(const node_iterator& v) { return G.id(v); }
marci@9: 
marci@17:     //node_iterator invalid_node() { return G.invalid_node(); }
marci@19:     //res_edge_it invalid_edge() { res_edge_it n; n.sym=G.invalid_sym_edge(); return n; } 
marci@9:   };
marci@9: 
marci@9:   template <typename graph_type, typename T>
marci@9:   struct max_flow_type {
marci@19:     typedef typename graph_type::node_iterator node_iterator;
marci@19:     typedef typename graph_type::edge_iterator edge_iterator;
marci@19:     typedef typename graph_type::each_node_iterator each_node_iterator;
marci@19:     typedef typename graph_type::out_edge_iterator out_edge_iterator;
marci@19:     typedef typename graph_type::in_edge_iterator in_edge_iterator;
marci@9:     graph_type& G;
marci@9:     node_iterator s;
marci@9:     node_iterator t;
marci@9:     edge_property_vector<graph_type, T> flow;
marci@9:     edge_property_vector<graph_type, T>& capacity;
marci@9: 
marci@9:     max_flow_type(graph_type& _G, node_iterator _s, node_iterator _t, edge_property_vector<graph_type, T>& _capacity) : G(_G), s(_s), t(_t), flow(_G), capacity(_capacity) { 
marci@19:       for(each_node_iterator i=G.first_node(); i.valid(); ++i) 
marci@19: 	for(out_edge_iterator j=G.first_out_edge(i); j.valid(); ++j) 
marci@9: 	  flow.put(j, 0);
marci@9:     }
marci@9:     void run() {
marci@9:       typedef res_graph_type<graph_type, T> aug_graph_type;
marci@9:       aug_graph_type res_graph(G, flow, capacity);
marci@9: 
marci@9:       bool augment;
marci@9:       do {
marci@9: 	augment=false;
marci@14: 
marci@19: 	typedef std::queue<aug_graph_type::out_edge_iterator> bfs_queue_type;
marci@14: 	bfs_queue_type bfs_queue;
marci@9: 	bfs_queue.push(res_graph.first_out_edge(s));
marci@14: 
marci@14: 	typedef node_property_vector<aug_graph_type, bool> reached_type;
marci@14: 	reached_type reached(res_graph, false);
marci@9: 	reached.put(s, true); 
marci@9: 	
marci@14: 	bfs_iterator1< aug_graph_type, reached_type > 
marci@14: 	res_bfs(res_graph, bfs_queue, reached);
marci@14: 
marci@19: 	typedef node_property_vector<aug_graph_type, aug_graph_type::edge_iterator> pred_type;
marci@14: 	pred_type pred(res_graph);
marci@19: 	aug_graph_type::edge_iterator a; 
marci@17: 	a.make_invalid();
marci@17: 	pred.put(s, a);
marci@14: 
marci@14: 	typedef node_property_vector<aug_graph_type, int> free_type;
marci@14: 	free_type free(res_graph);
marci@14: 	
marci@9: 	//searching for augmenting path
marci@19: 	while ( res_bfs.valid() ) { 
marci@14: 	  //std::cout<<"KULSO ciklus itt jar: "<<G.id(res_graph.tail(res_bfs))<<"->"<<G.id(res_graph.head(res_bfs))<<std::endl;
marci@19: 	  if (res_bfs.newly_reached()) {
marci@19: 	    aug_graph_type::edge_iterator e;
marci@14: 	    e=res_bfs;
marci@14: 	    node_iterator v=res_graph.tail(e);
marci@14: 	    node_iterator w=res_graph.head(e);
marci@14: 	    //std::cout<<G.id(v)<<"->"<<G.id(w)<<", "<<G.id(w)<<" is newly reached";
marci@14: 	    pred.put(w, e);
marci@19: 	    if (pred.get(v).valid()) {
marci@14: 	      free.put(w, std::min(free.get(v), e.free()));
marci@14: 	      //std::cout <<" nem elso csucs: ";
marci@14: 	      //std::cout <<"szabad kap eddig: "<< free.get(w) << " ";
marci@14: 	    } else {
marci@14: 	      free.put(w, e.free()); 
marci@14: 	      //std::cout <<" elso csucs: ";
marci@14: 	      //std::cout <<"szabad kap eddig: "<< free.get(w) << " ";
marci@14: 	    }
marci@14: 	    //std::cout<<std::endl;
marci@14: 	  }
marci@14: 	
marci@9: 	  if (res_graph.head(res_bfs)==t) break;
marci@9: 	  ++res_bfs;
marci@9: 	}
marci@9: 	if (reached.get(t)) {
marci@9: 	  augment=true;
marci@9: 	  node_iterator n=t;
marci@9: 	  T augment_value=free.get(t);
marci@9: 	  std::cout<<"augmentation: ";
marci@19: 	  while (pred.get(n).valid()) { 
marci@19: 	    aug_graph_type::edge_iterator e=pred.get(n);
marci@9: 	    e.augment(augment_value); 
marci@9: 	    std::cout<<"("<<res_graph.tail(e)<< "->"<<res_graph.head(e)<<") ";
marci@9: 	    n=res_graph.tail(e);
marci@9: 	  }
marci@9: 	  std::cout<<std::endl;
marci@9: 	}
marci@9: 
marci@14: 	std::cout << "actual flow: "<< std::endl;
marci@19: 	for(typename graph_type::each_edge_iterator e=G.first_edge(); e.valid(); ++e) { 
marci@9: 	  std::cout<<"("<<G.tail(e)<< "-"<<flow.get(e)<<"->"<<G.head(e)<<") ";
marci@9: 	}
marci@9: 	std::cout<<std::endl;
marci@9: 
marci@9:       } while (augment);
marci@9:     }
marci@9:   };
marci@9: 
marci@9: } // namespace marci
marci@9: 
marci@9: #endif //MARCI_MAX_FLOW_HH