Improved docs.
     1 #ifndef MARCI_MAX_FLOW_HH
 
     2 #define MARCI_MAX_FLOW_HH
 
     6 #include <marci_property_vector.hh>
 
     7 #include <marci_bfs.hh>
 
    11   template<typename graph_type, typename T>
 
    12   class res_graph_type { 
 
    13     typedef typename graph_type::node_iterator node_iterator;
 
    14     typedef typename graph_type::each_node_iterator each_node_iterator;
 
    15     typedef typename graph_type::sym_edge_iterator old_sym_edge_iterator;
 
    17     edge_property_vector<graph_type, T>& flow;
 
    18     edge_property_vector<graph_type, T>& capacity;
 
    20     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) { }
 
    23       friend class res_graph_type<graph_type, T>;
 
    25       res_graph_type<graph_type, T>* resG;
 
    26       old_sym_edge_iterator sym;
 
    30       //if (resG->G.a_node(sym)==resG->G.tail(sym)) { 
 
    31       //  return (resG->flow.get(sym)<resG->capacity.get(sym)); 
 
    33       //  return (resG->flow.get(sym)>0); 
 
    37 	if (resG->G.a_node(sym)==resG->G.tail(sym)) { 
 
    38 	  return (resG->capacity.get(sym)-resG->flow.get(sym)); 
 
    40 	  return (resG->flow.get(sym)); 
 
    43       bool valid() { return sym.valid(); }
 
    44       void make_invalid() { sym.make_invalid(); }
 
    46 	if (resG->G.a_node(sym)==resG->G.tail(sym)) { 
 
    47 	  resG->flow.put(sym, resG->flow.get(sym)+a);
 
    49 	  resG->flow.put(sym, resG->flow.get(sym)-a);
 
    54     class out_edge_iterator : public edge_iterator {
 
    56       out_edge_iterator() { }
 
    57       out_edge_iterator(res_graph_type<graph_type, T>& _resG, const node_iterator& v) { 
 
    59 	sym=resG->G.first_sym_edge(v);
 
    60 	while( sym.valid() && !(free()>0) ) { ++sym; }
 
    62       out_edge_iterator& operator++() { 
 
    64 	while( sym.valid() && !(free()>0) ) { ++sym; }
 
    69     out_edge_iterator first_out_edge(const node_iterator& v) {
 
    70       return out_edge_iterator(*this, v);
 
    73     each_node_iterator first_node() {
 
    74       return G.first_node();
 
    77     node_iterator tail(const edge_iterator& e) { return G.a_node(e.sym); }
 
    78     node_iterator head(const edge_iterator& e) { return G.b_node(e.sym); }
 
    80     int id(const node_iterator& v) { return G.id(v); }
 
    82     //node_iterator invalid_node() { return G.invalid_node(); }
 
    83     //res_edge_it invalid_edge() { res_edge_it n; n.sym=G.invalid_sym_edge(); return n; } 
 
    86   template <typename graph_type, typename T>
 
    87   struct max_flow_type {
 
    88     typedef typename graph_type::node_iterator node_iterator;
 
    89     typedef typename graph_type::edge_iterator edge_iterator;
 
    90     typedef typename graph_type::each_node_iterator each_node_iterator;
 
    91     typedef typename graph_type::out_edge_iterator out_edge_iterator;
 
    92     typedef typename graph_type::in_edge_iterator in_edge_iterator;
 
    96     edge_property_vector<graph_type, T> flow;
 
    97     edge_property_vector<graph_type, T>& capacity;
 
    99     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) { 
 
   100       for(each_node_iterator i=G.first_node(); i.valid(); ++i) 
 
   101 	for(out_edge_iterator j=G.first_out_edge(i); j.valid(); ++j) 
 
   105       typedef res_graph_type<graph_type, T> aug_graph_type;
 
   106       aug_graph_type res_graph(G, flow, capacity);
 
   112 	typedef std::queue<aug_graph_type::out_edge_iterator> bfs_queue_type;
 
   113 	bfs_queue_type bfs_queue;
 
   114 	bfs_queue.push(res_graph.first_out_edge(s));
 
   116 	typedef node_property_vector<aug_graph_type, bool> reached_type;
 
   117 	reached_type reached(res_graph, false);
 
   118 	reached.put(s, true); 
 
   120 	bfs_iterator1< aug_graph_type, reached_type > 
 
   121 	res_bfs(res_graph, bfs_queue, reached);
 
   123 	typedef node_property_vector<aug_graph_type, aug_graph_type::edge_iterator> pred_type;
 
   124 	pred_type pred(res_graph);
 
   125 	aug_graph_type::edge_iterator a; 
 
   129 	typedef node_property_vector<aug_graph_type, int> free_type;
 
   130 	free_type free(res_graph);
 
   132 	//searching for augmenting path
 
   133 	while ( res_bfs.valid() ) { 
 
   134 	  //std::cout<<"KULSO ciklus itt jar: "<<G.id(res_graph.tail(res_bfs))<<"->"<<G.id(res_graph.head(res_bfs))<<std::endl;
 
   135 	  if (res_bfs.newly_reached()) {
 
   136 	    aug_graph_type::edge_iterator e;
 
   138 	    node_iterator v=res_graph.tail(e);
 
   139 	    node_iterator w=res_graph.head(e);
 
   140 	    //std::cout<<G.id(v)<<"->"<<G.id(w)<<", "<<G.id(w)<<" is newly reached";
 
   142 	    if (pred.get(v).valid()) {
 
   143 	      free.put(w, std::min(free.get(v), e.free()));
 
   144 	      //std::cout <<" nem elso csucs: ";
 
   145 	      //std::cout <<"szabad kap eddig: "<< free.get(w) << " ";
 
   147 	      free.put(w, e.free()); 
 
   148 	      //std::cout <<" elso csucs: ";
 
   149 	      //std::cout <<"szabad kap eddig: "<< free.get(w) << " ";
 
   151 	    //std::cout<<std::endl;
 
   154 	  if (res_graph.head(res_bfs)==t) break;
 
   157 	if (reached.get(t)) {
 
   160 	  T augment_value=free.get(t);
 
   161 	  std::cout<<"augmentation: ";
 
   162 	  while (pred.get(n).valid()) { 
 
   163 	    aug_graph_type::edge_iterator e=pred.get(n);
 
   164 	    e.augment(augment_value); 
 
   165 	    std::cout<<"("<<res_graph.tail(e)<< "->"<<res_graph.head(e)<<") ";
 
   168 	  std::cout<<std::endl;
 
   171 	std::cout << "actual flow: "<< std::endl;
 
   172 	for(typename graph_type::each_edge_iterator e=G.first_edge(); e.valid(); ++e) { 
 
   173 	  std::cout<<"("<<G.tail(e)<< "-"<<flow.get(e)<<"->"<<G.head(e)<<") ";
 
   175 	std::cout<<std::endl;
 
   183 #endif //MARCI_MAX_FLOW_HH