src/include/bfs.h
author marci
Thu, 11 Mar 2004 14:15:07 +0000
changeset 168 27fbd1559fb7
parent 6 b63d1bc367f7
permissions -rw-r--r--
graph wrapper improvements, blocking flow on fly
     1 // -*-mode: c++; -*-
     2 #ifndef _BFS_H_
     3 #define _BFS_H_
     4 
     5 #include <queue>
     6 #include <graph.h>
     7 
     8 namespace NEGRO 
     9 {
    10   using namespace std;
    11   
    12   //   template <typename G,typename> class bfs_T
    13   //   {
    14   //     typedef G Graph;
    15   //     typedef Graph::OutEdgeIterator EdgeIterator; //Ez kell
    16   //     typedef Graph::NodeIterator NodeIterator;
    17     
    18   //     class bfs_node_D 
    19   //     {
    20   //       EdgeIterator Tree;
    21   //       int Dist;
    22   //       int Priority;
    23   //     }
    24   //   }
    25     
    26 
    27   //     //    template <bfs_T<G>>
    28   //     //    void bfs(bfs_T::Graph &G,const bfs_T::NodeIterator &start_node,const &maps)
    29 
    30     
    31   
    32   //   template <class G>
    33   //   class bfs_maps_T
    34   //   {
    35   //     typedef visited; //node->bool (RW)
    36   //     typedef tree;    //node->EdgeIterator (W)
    37   //     typedef dist;   //node->int (W)
    38   //     typedef priority; //node->int (W)
    39   //   };
    40   
    41   
    42   //   Nem jo! Osszeakad a masik Put-tal
    43   //   class do_nothing_map {};
    44   //   template <typename V,typename T>
    45   //   void Put(const do_nothing_map &p,const V &v,const T &t) {}
    46   
    47   struct do_nothing_map {
    48     template <typename V,typename T> static void Put(V v,T t) {}
    49     template <typename G> void SetG(G &g) {}
    50   };
    51   
    52 
    53   template <typename I,typename C, typename T, T C::*M>
    54   class class_element_map {
    55   public:
    56     typedef T value_type;
    57     static void Put(const I &i, const T &t) {(*i).*M=t;}
    58     static T Get(const I i) {return (*i).*M;}
    59     T &operator[](I i) {return (*i).*M;}
    60   };
    61 
    62   /* 
    63      template <typename C,typename I,typename T, T C::*M>
    64      void Put(class_element_map<C,T,M> p,I i, T t)
    65      {
    66      i->*M=t;   
    67      };
    68   */
    69 
    70   template <typename P,typename I,typename T>
    71   inline void Put(P &p,const I &i, const T &t)
    72   {
    73     p.Put(i,t);   
    74   };
    75   template <typename P,typename I>
    76   inline typename P::value_type Get(const P &p,const I &i)
    77   {
    78     return p.Get(i);   
    79   };
    80 
    81   /*
    82     template <typename G,typename T, typename G::EdgeType::*M>
    83     T Get(edge_element_map p,G::EdgeIterator i)
    84     {
    85     return i->*M;
    86     };
    87   */
    88   
    89   /* 
    90      template <class G>
    91      class default_bfs_maps
    92      {
    93      public:
    94      typedef typename G::NodeType NodeType;
    95     
    96      class_element_map<typename G::NodeIterator,
    97      typename G::NodeType,
    98      bool,&NodeType::isVis> visited; //node->bool (RW)
    99      do_nothing_map tree;   //node->EdgeIterator (W)
   100      do_nothing_map dist;   //node->int (W)
   101      do_nothing_map priority; //node->int (W)
   102      };
   103   */
   104 
   105   template<class G>
   106   struct bfs_node_data 
   107   {
   108     bool visited;
   109     typename G::EdgeIterator tree;
   110     int dist;
   111     int priority;
   112   };
   113   
   114   template <class G>
   115   class bfs_static_maps
   116   {
   117   public:
   118     typedef typename G::NodeType NodeType;
   119     
   120     /*    class_element_map<typename G::NodeIterator,
   121 	  typename G::NodeType,
   122 	  bfs_node_data<G>,&NT::D> n_d; //node-> data
   123     */
   124     class 
   125     {
   126     public:
   127       bfs_node_data<G> NodeType::*d;
   128       typedef bool value_type;
   129       void Put(typename G::NodeIterator &i, const value_type &t)
   130       {((*i).*d).visited=t;}
   131       value_type Get(const typename G::NodeIterator &i) const
   132       {return ((*i).*d).visited;}
   133     } visited;
   134     
   135     class 
   136     {
   137     public:
   138       bfs_node_data<G> NodeType::*d;
   139       typedef typename G::EdgeIterator value_type;
   140       void Put(typename G::NodeIterator &i, const value_type &t)
   141       {((*i).*d).tree=t;}
   142       value_type Get(const typename G::NodeIterator &i) const
   143       {return ((*i).*d).tree;}
   144     } tree;
   145     
   146     class 
   147     {
   148     public:
   149       bfs_node_data<G> NodeType::*d;
   150       typedef int value_type;
   151       void Put(typename G::NodeIterator &i, const value_type &t)
   152       {((*i).*d).dist=t;}
   153       value_type Get(const typename G::NodeIterator &i) const
   154       {return ((*i).*d).dist;}
   155     } dist;
   156     
   157     class 
   158     {
   159     public:
   160       bfs_node_data<G> NodeType::*d;
   161       typedef int value_type;
   162       void Put(typename G::NodeIterator &i,  const value_type &t)
   163       {((*i).*d).priority=t;}
   164       value_type Get(const typename G::NodeIterator &i) const
   165       {return ((*i).*d).priority;}
   166     } priority;
   167     
   168     //do_nothing_map tree;   //node->EdgeIterator (W)
   169     //    do_nothing_map dist;   //node->int (W)
   170     //    do_nothing_map priority; //node->int (W)
   171 
   172     void SetDataField(const bfs_node_data<G> NodeType::*dd)
   173     {
   174       tree.d=visited.d=dist.d=priority.d=dd;
   175     }
   176     
   177     bfs_static_maps(const bfs_node_data<G> NodeType::*dd) 
   178     {
   179       PutDataField(dd);
   180     }
   181     
   182     bfs_static_maps(const bfs_static_maps<G> &B) 
   183     {
   184       tree.d=B.tree.d;visited.d=B.visited.d;
   185       dist.d=B.dist.d;priority.d=B.priority.d;
   186     }
   187     
   188   };
   189   
   190   template<typename I>
   191   struct BFS_Q
   192   {
   193     I n;
   194     int dist;
   195     //  BFS_Q() {}
   196     //  BFS_Q(BFS_Q<I> &b) {n=b.n;dist=b.dist;}
   197   };
   198   
   199   template<class G,class M>
   200   void bfs_fn(G &Gr,const typename G::NodeIterator &start_node,M &maps)
   201   {
   202     using namespace std;
   203     
   204     typedef BFS_Q<typename G::NodeIterator> Q_T;
   205     
   206     Q_T q;
   207     
   208     int pr=0;
   209     typename G::NodeIterator n,m;
   210     typename G::OutEdgeIterator e;
   211     int d;
   212     
   213     for(Gr.GetFirst(n);n.isValid();++n)
   214       Put(maps.visited,n,false);
   215     
   216     queue<Q_T> Q;
   217     
   218     q.n=start_node;
   219     q.dist=0;
   220     Q.push(q);
   221     Put(maps.visited,start_node,true);
   222     //      Put(maps::tree,start_node,?????);
   223     Put(maps.dist,start_node,0);
   224     Put(maps.priority,start_node,pr++);
   225     
   226     do {
   227       n=Q.front().n;d=Q.front().dist+1;
   228       Q.pop();
   229       for(Gr.GetFirst(e,n);e.isValid();++e)
   230 	if(!Get(maps.visited,(m=e.Bnode()))) {
   231 	  q.n=m;
   232 	  q.dist=d;
   233 	  Q.push(q);
   234 	  Put(maps.visited,m,true);
   235 	  Put(maps.tree,m,e);
   236 	  Put(maps.dist,m,d);
   237 	  Put(maps.priority,m,pr++);
   238 	}
   239     } while(!Q.empty());
   240   };
   241 
   242   // bfs algorithm class
   243 
   244   template<class G>  //the default traits
   245   class default_bfs_T
   246   {
   247   public:
   248     
   249     typedef G Graph;
   250     typedef typename G::OutEdgeIterator SearchEdgeIterator;
   251     
   252     typedef typename G::NodeMap<bool> visited_map_t;
   253     typedef typename G::NodeMap<typename G::EdgeIterator> tree_map_t;
   254     
   255     typedef typename G::NodeMap<int> dist_map_t;   //node->int (W)
   256     typedef typename G::NodeMap<int> priority_map_t; //node->int (W)
   257 };
   258 
   259   template<class T>
   260   class Bfs
   261   {
   262   public:
   263     typedef typename T::Graph Graph;
   264     typedef typename Graph::NodeIterator NodeIterator;
   265     typedef typename Graph::EdgeIterator EdgeIterator;
   266     
   267     typedef typename T::SearchEdgeIterator SearchEdgeIterator;
   268     
   269     typename T::visited_map_t visited_map;
   270     typename T::tree_map_t tree_map;
   271     typename T::dist_map_t dist_map;
   272     typename T::priority_map_t priority_map;
   273     
   274     struct bfs_queue_cont
   275     {
   276       NodeIterator n;
   277       int dist;
   278     };
   279     
   280     std::queue<bfs_queue_cont> bfs_queue;
   281     
   282     int priority;
   283     Graph *G;
   284     
   285     //Bfs(int i): visited_map(G), tree_map(G), dist_map(G), priority_map(G) {}
   286     Bfs() {}
   287 
   288     void SetG(Graph &Gr)
   289     {
   290       G=&Gr;
   291       visited_map.SetG(Gr);
   292       tree_map.SetG(Gr);
   293       dist_map.SetG(Gr);
   294       priority_map.SetG(Gr);
   295     }
   296     
   297     void Init()
   298     {
   299       //There must be a better way to do this:
   300       while(!bfs_queue.empty()) bfs_queue.pop();
   301 
   302       for(NodeIterator n(*G);n.isValid();++n)
   303 	Put(visited_map,n,false);
   304       
   305       priority=0;
   306     }
   307     
   308     void AddStartNode(const NodeIterator &start_node,int dist=0)
   309     {
   310       bfs_queue_cont q;
   311       q.n=start_node;
   312       q.dist=dist;
   313       bfs_queue.push(q);
   314 
   315       Put(visited_map,start_node,true);
   316       //      Put(tree_map,start_node,?????);
   317       Put(dist_map,start_node,dist);
   318       Put(priority_map,start_node,priority++);    
   319     }
   320     
   321     void Init(const NodeIterator &start_node,int dist=0)
   322     {
   323       Init();
   324       AddStartNode(start_node,dist);
   325     }
   326 
   327     void Run() 
   328     {
   329       NodeIterator n,m;
   330       int d;
   331 
   332       bfs_queue_cont q;
   333       while(!(bfs_queue.empty()/* && other stop conditions */)) {
   334 	n=bfs_queue.front().n;d=bfs_queue.front().dist+1;
   335 	bfs_queue.pop();
   336 	for(SearchEdgeIterator e(*G,n);e.isValid();++e)
   337 	  if(!Get(visited_map,(m=e.Bnode()))) {
   338 	    q.n=m;
   339 	    q.dist=d;
   340 	    bfs_queue.push(q);
   341 	    Put(visited_map,m,true);
   342 	    Put(tree_map,m,e);
   343 	    Put(dist_map,m,d);
   344 	    Put(priority_map,m,priority++);
   345 	  }
   346       }
   347     }
   348   };
   349   
   350 }
   351   
   352 #endif