alpar@948: /* -*- C++ -*-
alpar@948:  * src/lemon/list_graph.h - Part of LEMON, a generic C++ optimization library
alpar@948:  *
alpar@948:  * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
alpar@948:  * (Egervary Combinatorial Optimization Research Group, EGRES).
alpar@948:  *
alpar@948:  * Permission to use, modify and distribute this software is granted
alpar@948:  * provided that this copyright notice appears in all copies. For
alpar@948:  * precise terms see the accompanying LICENSE file.
alpar@948:  *
alpar@948:  * This software is provided "AS IS" with no warranty of any kind,
alpar@948:  * express or implied, and with no claim as to its suitability for any
alpar@948:  * purpose.
alpar@948:  *
alpar@948:  */
alpar@395: 
alpar@921: #ifndef LEMON_LIST_GRAPH_H
alpar@921: #define LEMON_LIST_GRAPH_H
alpar@395: 
alpar@948: ///\ingroup graphs
alpar@948: ///\file
alpar@948: ///\brief ListGraph, SymListGraph, NodeSet and EdgeSet classes.
alpar@948: 
klao@946: #include <lemon/erasable_graph_extender.h>
klao@946: #include <lemon/clearable_graph_extender.h>
klao@946: #include <lemon/extendable_graph_extender.h>
alpar@395: 
klao@946: #include <lemon/iterable_graph_extender.h>
alpar@395: 
klao@946: #include <lemon/alteration_observer_registry.h>
deba@782: 
klao@946: #include <lemon/default_map.h>
deba@782: 
alpar@1011: #include <list>
deba@782: 
alpar@921: namespace lemon {
alpar@395: 
klao@946:   class ListGraphBase {
alpar@406: 
alpar@949:   protected:
klao@946:     struct NodeT {
alpar@397:       int first_in,first_out;
alpar@397:       int prev, next;
alpar@395:     };
klao@946:  
klao@946:     struct EdgeT {
alpar@986:       int target, source;
alpar@397:       int prev_in, prev_out;
alpar@397:       int next_in, next_out;
alpar@395:     };
alpar@395: 
alpar@395:     std::vector<NodeT> nodes;
klao@946: 
alpar@397:     int first_node;
klao@946: 
alpar@397:     int first_free_node;
klao@946: 
alpar@395:     std::vector<EdgeT> edges;
klao@946: 
alpar@397:     int first_free_edge;
alpar@395:     
deba@782:   public:
alpar@395:     
klao@946:     typedef ListGraphBase Graph;
alpar@397:     
klao@946:     class Node {
marci@975:       friend class ListGraphBase;
klao@946:     protected:
alpar@395: 
klao@946:       int id;
klao@946:       Node(int pid) { id = pid;}
alpar@395: 
klao@946:     public:
klao@946:       Node() {}
klao@946:       Node (Invalid) { id = -1; }
klao@946:       bool operator==(const Node& node) const {return id == node.id;}
klao@946:       bool operator!=(const Node& node) const {return id != node.id;}
klao@946:       bool operator<(const Node& node) const {return id < node.id;}
klao@946:     };
deba@782: 
klao@946:     class Edge {
marci@975:       friend class ListGraphBase;
klao@946:     protected:
deba@782: 
klao@946:       int id;
klao@946:       Edge(int pid) { id = pid;}
alpar@395: 
klao@946:     public:
klao@946:       Edge() {}
klao@946:       Edge (Invalid) { id = -1; }
klao@946:       bool operator==(const Edge& edge) const {return id == edge.id;}
klao@946:       bool operator!=(const Edge& edge) const {return id != edge.id;}
klao@946:       bool operator<(const Edge& edge) const {return id < edge.id;}
klao@946:     };
klao@946: 
klao@946: 
klao@946: 
klao@946:     ListGraphBase()
deba@782:       : nodes(), first_node(-1),
deba@782: 	first_free_node(-1), edges(), first_free_edge(-1) {}
deba@782: 
alpar@395:     
alpar@813:     /// Maximum node ID.
alpar@813:     
alpar@813:     /// Maximum node ID.
alpar@813:     ///\sa id(Node)
deba@980:     int maxId(Node = INVALID) const { return nodes.size()-1; } 
klao@946: 
alpar@813:     /// Maximum edge ID.
alpar@813:     
alpar@813:     /// Maximum edge ID.
alpar@813:     ///\sa id(Edge)
deba@980:     int maxId(Edge = INVALID) const { return edges.size()-1; }
alpar@395: 
alpar@986:     Node source(Edge e) const { return edges[e.id].source; }
alpar@986:     Node target(Edge e) const { return edges[e.id].target; }
alpar@395: 
alpar@395: 
klao@946:     void first(Node& node) const { 
klao@946:       node.id = first_node;
klao@946:     }
klao@946: 
klao@946:     void next(Node& node) const {
klao@946:       node.id = nodes[node.id].next;
klao@946:     }
klao@946: 
klao@946: 
klao@946:     void first(Edge& e) const { 
klao@946:       int n;
klao@946:       for(n = first_node; 
klao@946: 	  n!=-1 && nodes[n].first_in == -1; 
klao@946: 	  n = nodes[n].next);
klao@946:       e.id = (n == -1) ? -1 : nodes[n].first_in;
klao@946:     }
klao@946: 
klao@946:     void next(Edge& edge) const {
klao@946:       if (edges[edge.id].next_in != -1) {
klao@946: 	edge.id = edges[edge.id].next_in;
klao@946:       } else {
klao@946: 	int n;
alpar@986: 	for(n = nodes[edges[edge.id].target].next;
klao@946: 	  n!=-1 && nodes[n].first_in == -1; 
klao@946: 	  n = nodes[n].next);
klao@946: 	edge.id = (n == -1) ? -1 : nodes[n].first_in;
klao@946:       }      
klao@946:     }
klao@946: 
klao@946:     void firstOut(Edge &e, const Node& v) const {
klao@946:       e.id = nodes[v.id].first_out;
klao@946:     }
klao@946:     void nextOut(Edge &e) const {
klao@946:       e.id=edges[e.id].next_out;
klao@946:     }
klao@946: 
klao@946:     void firstIn(Edge &e, const Node& v) const {
klao@946:       e.id = nodes[v.id].first_in;
klao@946:     }
klao@946:     void nextIn(Edge &e) const {
klao@946:       e.id=edges[e.id].next_in;
klao@946:     }
klao@946: 
alpar@813:     
klao@946:     static int id(Node v) { return v.id; }
klao@946:     static int id(Edge e) { return e.id; }
alpar@395: 
alpar@397:     /// Adds a new node to the graph.
alpar@397: 
alpar@813:     /// \warning It adds the new node to the front of the list.
alpar@397:     /// (i.e. the lastly added node becomes the first.)
klao@946:     Node addNode() {     
alpar@397:       int n;
alpar@397:       
klao@946:       if(first_free_node==-1) {
klao@946: 	n = nodes.size();
klao@946: 	nodes.push_back(NodeT());
klao@946:       } else {
alpar@397: 	n = first_free_node;
alpar@397: 	first_free_node = nodes[n].next;
alpar@397:       }
alpar@397:       
alpar@397:       nodes[n].next = first_node;
alpar@397:       if(first_node != -1) nodes[first_node].prev = n;
alpar@397:       first_node = n;
alpar@397:       nodes[n].prev = -1;
alpar@397:       
alpar@397:       nodes[n].first_in = nodes[n].first_out = -1;
alpar@397:       
klao@946:       return Node(n);
alpar@395:     }
alpar@395:     
alpar@395:     Edge addEdge(Node u, Node v) {
klao@946:       int n;      
klao@946: 
klao@946:       if (first_free_edge == -1) {
klao@946: 	n = edges.size();
klao@946: 	edges.push_back(EdgeT());
klao@946:       } else {
alpar@397: 	n = first_free_edge;
alpar@397: 	first_free_edge = edges[n].next_in;
alpar@397:       }
alpar@397:       
alpar@986:       edges[n].source = u.id; 
alpar@986:       edges[n].target = v.id;
alpar@395: 
klao@946:       edges[n].next_out = nodes[u.id].first_out;
klao@946:       if(nodes[u.id].first_out != -1) {
klao@946: 	edges[nodes[u.id].first_out].prev_out = n;
klao@946:       }
klao@946:       
klao@946:       edges[n].next_in = nodes[v.id].first_in;
klao@946:       if(nodes[v.id].first_in != -1) {
klao@946: 	edges[nodes[v.id].first_in].prev_in = n;
klao@946:       }
klao@946:       
alpar@397:       edges[n].prev_in = edges[n].prev_out = -1;
alpar@397: 	
klao@946:       nodes[u.id].first_out = nodes[v.id].first_in = n;
alpar@397: 
klao@946:       return Edge(n);
alpar@395:     }
alpar@774:     
klao@946:     void erase(const Node& node) {
klao@946:       int n = node.id;
klao@946:       
klao@946:       if(nodes[n].next != -1) {
klao@946: 	nodes[nodes[n].next].prev = nodes[n].prev;
klao@946:       }
klao@946:       
klao@946:       if(nodes[n].prev != -1) {
klao@946: 	nodes[nodes[n].prev].next = nodes[n].next;
klao@946:       } else {
klao@946: 	first_node = nodes[n].next;
klao@946:       }
klao@946:       
klao@946:       nodes[n].next = first_free_node;
klao@946:       first_free_node = n;
alpar@395: 
alpar@774:     }
alpar@774:     
klao@946:     void erase(const Edge& edge) {
klao@946:       int n = edge.id;
alpar@397:       
klao@946:       if(edges[n].next_in!=-1) {
alpar@397: 	edges[edges[n].next_in].prev_in = edges[n].prev_in;
klao@946:       }
klao@946: 
klao@946:       if(edges[n].prev_in!=-1) {
alpar@397: 	edges[edges[n].prev_in].next_in = edges[n].next_in;
klao@946:       } else {
alpar@986: 	nodes[edges[n].target].first_in = edges[n].next_in;
klao@946:       }
klao@946: 
alpar@397:       
klao@946:       if(edges[n].next_out!=-1) {
alpar@397: 	edges[edges[n].next_out].prev_out = edges[n].prev_out;
klao@946:       } 
klao@946: 
klao@946:       if(edges[n].prev_out!=-1) {
alpar@397: 	edges[edges[n].prev_out].next_out = edges[n].next_out;
klao@946:       } else {
alpar@986: 	nodes[edges[n].source].first_out = edges[n].next_out;
klao@946:       }
alpar@397:       
alpar@397:       edges[n].next_in = first_free_edge;
alpar@695:       first_free_edge = n;      
alpar@397: 
alpar@397:     }
alpar@397: 
alpar@397:     void clear() {
deba@782:       edges.clear();
deba@782:       nodes.clear();
klao@946:       first_node = first_free_node = first_free_edge = -1;
deba@937:     }
deba@937: 
alpar@949:   protected:
alpar@986:     void _moveTarget(Edge e, Node n) 
alpar@949:     {
alpar@949:       if(edges[e.id].next_in != -1)
alpar@949: 	edges[edges[e.id].next_in].prev_in = edges[e.id].prev_in;
alpar@949:       if(edges[e.id].prev_in != -1)
alpar@949: 	edges[edges[e.id].prev_in].next_in = edges[e.id].next_in;
alpar@986:       else nodes[edges[e.id].target].first_in = edges[e.id].next_in;
alpar@986:       edges[e.id].target = n.id;
alpar@949:       edges[e.id].prev_in = -1;
alpar@949:       edges[e.id].next_in = nodes[n.id].first_in;
alpar@949:       nodes[n.id].first_in = e.id;
alpar@949:     }
alpar@986:     void _moveSource(Edge e, Node n) 
alpar@949:     {
alpar@949:       if(edges[e.id].next_out != -1)
alpar@949: 	edges[edges[e.id].next_out].prev_out = edges[e.id].prev_out;
alpar@949:       if(edges[e.id].prev_out != -1)
alpar@949: 	edges[edges[e.id].prev_out].next_out = edges[e.id].next_out;
alpar@986:       else nodes[edges[e.id].source].first_out = edges[e.id].next_out;
alpar@986:       edges[e.id].source = n.id;
alpar@949:       edges[e.id].prev_out = -1;
alpar@949:       edges[e.id].next_out = nodes[n.id].first_out;
alpar@949:       nodes[n.id].first_out = e.id;
alpar@949:     }
alpar@949: 
alpar@919:   };
deba@909: 
klao@946:   typedef AlterableGraphExtender<ListGraphBase> AlterableListGraphBase;
klao@946:   typedef IterableGraphExtender<AlterableListGraphBase> IterableListGraphBase;
deba@980:   typedef DefaultMappableGraphExtender<IterableListGraphBase> MappableListGraphBase;
klao@946:   typedef ExtendableGraphExtender<MappableListGraphBase> ExtendableListGraphBase;
klao@946:   typedef ClearableGraphExtender<ExtendableListGraphBase> ClearableListGraphBase;
klao@946:   typedef ErasableGraphExtender<ClearableListGraphBase> ErasableListGraphBase;
alpar@400: 
alpar@948: /// \addtogroup graphs
alpar@948: /// @{
alpar@400: 
alpar@948:   ///A list graph class.
alpar@400: 
alpar@948:   ///This is a simple and fast erasable graph implementation.
alpar@948:   ///
alpar@1010:   ///It addition that it conforms to the
alpar@1010:   ///\ref concept::ErasableGraph "ErasableGraph" concept,
alpar@1010:   ///it also provides several additional useful extra functionalities.
klao@959:   ///\sa concept::ErasableGraph.
deba@782: 
alpar@948:   class ListGraph : public ErasableListGraphBase 
alpar@948:   {
alpar@948:   public:
alpar@986:     /// Moves the target of \c e to \c n
alpar@948: 
alpar@986:     /// Moves the target of \c e to \c n
alpar@948:     ///
alpar@1010:     ///\note The <tt>Edge</tt>'s and <tt>OutEdge</tt>'s
alpar@1010:     ///referencing the moved edge remain
alpar@1010:     ///valid. However <tt>InEdge</tt>'s are invalidated.
alpar@986:     void moveTarget(Edge e, Node n) { _moveTarget(e,n); }
alpar@986:     /// Moves the source of \c e to \c n
alpar@948: 
alpar@986:     /// Moves the source of \c e to \c n
alpar@948:     ///
alpar@1010:     ///\note The <tt>Edge</tt>'s and <tt>InEdge</tt>'s
alpar@1010:     ///referencing the moved edge remain
alpar@1010:     ///valid. However <tt>OutEdge</tt>'s are invalidated.
alpar@986:     void moveSource(Edge e, Node n) { _moveSource(e,n); }
alpar@949: 
alpar@1010:     /// Invert the direction of an edge.
alpar@1010: 
alpar@1010:     ///\note The <tt>Edge</tt>'s
alpar@1010:     ///referencing the moved edge remain
alpar@1010:     ///valid. However <tt>OutEdge</tt>'s  and <tt>InEdge</tt>'s are invalidated.
alpar@1010:     void reverseEdge(Edge e) {
alpar@1010:       Node t=target(e);
alpar@1010:       _moveTarget(e,source(e));
alpar@1010:       _moveSource(e,t);
alpar@1010:     }
alpar@1010: 
alpar@1010:     ///Using this it possible to avoid the superfluous memory allocation.
alpar@1010: 
alpar@949:     ///Using this it possible to avoid the superfluous memory allocation.
alpar@949:     ///\todo more docs...
alpar@949:     void reserveEdge(int n) { edges.reserve(n); };
alpar@1010: 
alpar@1010:     ///Contract two nodes.
alpar@1010: 
alpar@1010:     ///This function contracts two nodes.
alpar@1010:     ///
alpar@1010:     ///Node \p b will be removed but instead of deleting
alpar@1010:     ///its neighboring edges, they will be joined to \p a.
alpar@1010:     ///The last parameter \p r controls whether to remove loops. \c true
alpar@1010:     ///means that loops will be removed.
alpar@1010:     ///
alpar@1010:     ///\note The <tt>Edge</tt>s
alpar@1010:     ///referencing the moved edge remain
alpar@1010:     ///valid. However <tt>InEdge</tt>'s and <tt>OutEdge</tt>'s
alpar@1010:     ///may be invalidated.
alpar@1010:     void contract(Node a,Node b,bool r=true) 
alpar@1010:     {
alpar@1010:       for(OutEdgeIt e(*this,b);e!=INVALID;) {
alpar@1010: 	OutEdgeIt f=e;
alpar@1010: 	++f;
alpar@1010: 	if(r && target(e)==a) erase(e);
alpar@1010: 	else moveSource(e,b);
alpar@1010: 	e=f;
alpar@1010:       }
alpar@1010:       for(InEdgeIt e(*this,b);e!=INVALID;) {
alpar@1010: 	InEdgeIt f=e;
alpar@1010: 	++f;
alpar@1010: 	if(r && source(e)==a) erase(e);
alpar@1010: 	else moveTarget(e,b);
alpar@1010: 	e=f;
alpar@1010:       }
alpar@1010:       erase(b);
alpar@1010:     }
alpar@1011: 
alpar@1011: 
alpar@1011:     ///Class to make a snapshot of the graph and to restrore to it later.
alpar@1011: 
alpar@1011:     ///Class to make a snapshot of the graph and to restrore to it later.
alpar@1011:     ///
alpar@1011:     ///The newly added nodes and edges can be removed using the
alpar@1011:     ///restore() function.
alpar@1011:     ///
alpar@1011:     ///\warning Edge and node deletions cannot be restored.
alpar@1011:     ///\warning SnapShots cannot be nested.
alpar@1011:     ///\ingroup graphs
alpar@1012:     class SnapShot : protected AlterationObserverRegistry<Node>::ObserverBase,
alpar@1012: 		     protected AlterationObserverRegistry<Edge>::ObserverBase
alpar@1011:     {
alpar@1011:       protected:
alpar@1011:       
alpar@1011:       ListGraph *g;
alpar@1011:       std::list<Node> added_nodes;
alpar@1011:       std::list<Edge> added_edges;
alpar@1011:       
alpar@1011:       bool active;
alpar@1011:       virtual void add(const Node& n) {
alpar@1011: 	added_nodes.push_back(n);
alpar@1011:       };
alpar@1011:       ///\bug Exception...
alpar@1011:       ///
alpar@1011:       virtual void erase(const Node&) 
alpar@1011:       {
alpar@1011: 	exit(1);
alpar@1011:       }
alpar@1011:       virtual void add(const Edge& n) {
alpar@1011: 	added_edges.push_back(n);
alpar@1011:       };
alpar@1011:       ///\bug Exception...
alpar@1011:       ///
alpar@1011:       virtual void erase(const Edge&) 
alpar@1011:       {
alpar@1011: 	exit(1);
alpar@1011:       }
alpar@1011: 
alpar@1011:       void regist(ListGraph &_g) {
alpar@1011: 	g=&_g;
alpar@1011: 	AlterationObserverRegistry<Node>::ObserverBase::
alpar@1011: 	  attach(g->node_observers);
alpar@1011: 	AlterationObserverRegistry<Edge>::ObserverBase::
alpar@1011: 	  attach(g->edge_observers);
alpar@1011:       }
alpar@1011:             
alpar@1011:       void deregist() {
alpar@1011: 	AlterationObserverRegistry<Node>::ObserverBase::
alpar@1011: 	  detach();
alpar@1011: 	AlterationObserverRegistry<Edge>::ObserverBase::
alpar@1011: 	  detach();
alpar@1011: 	g=0;
alpar@1011:       }
alpar@1011:             
alpar@1011:     public:
alpar@1011:       ///Default constructur.
alpar@1011:       
alpar@1011:       ///Default constructur.
alpar@1011:       ///To actually make a snapshot you must call save().
alpar@1011:       ///
alpar@1011:       SnapShot() : g(0) {}
alpar@1011:       ///Constructor that immediately makes a snapshot.
alpar@1011:       
alpar@1011:       ///This constructor immediately makes a snapshot of the graph.
alpar@1011:       ///\param _g The graph we make a snapshot of.
alpar@1011:       SnapShot(ListGraph &_g) {
alpar@1011: 	regist(_g);
alpar@1011:       }
alpar@1011:       ///\bug Is it necessary?
alpar@1011:       ///
alpar@1011:       ~SnapShot() 
alpar@1011:       {
alpar@1011: 	if(g) deregist();
alpar@1011:       }
alpar@1011:       
alpar@1011:       ///Make a snapshot.
alpar@1011: 
alpar@1011:       ///Make a snapshot of the graph.
alpar@1011:       ///
alpar@1011:       ///This function can be called more than once. In case of a repeated
alpar@1011:       ///call, the previous snapshot gets lost.
alpar@1011:       ///\param _g The graph we make the snapshot of.
alpar@1011:       void save(ListGraph &_g) 
alpar@1011:       {
alpar@1011: 	if(g!=&_g) {
alpar@1011: 	  if(g) deregist();
alpar@1011: 	  regist(_g);
alpar@1011: 	}
alpar@1011: 	added_nodes.clear();
alpar@1011: 	added_edges.clear();
alpar@1011:       }
alpar@1011:       
alpar@1011:     ///Undo the changes until the last snapshot.
alpar@1011: 
alpar@1011:     ///Undo the changes until last snapshot created by save().
alpar@1011:     ///
alpar@1011:     ///\todo This function might be called undo().
alpar@1011:       void restore() {
alpar@1011: 	deregist();
alpar@1011: 	while(!added_edges.empty()) {
alpar@1011: 	  g->erase(added_edges.front());
alpar@1011: 	  added_edges.pop_front();
alpar@1011: 	}
alpar@1011:  	while(!added_nodes.empty()) {
alpar@1011: 	  g->erase(added_nodes.front());
alpar@1011: 	  added_nodes.pop_front();
alpar@1011: 	}
alpar@1011:       }
alpar@1011:     };
alpar@1011:     
alpar@949:   };
alpar@949:   
alpar@948:   /// @}  
alpar@948: } //namespace lemon
klao@946:   
alpar@400: 
klao@946: #endif