alpar@906: /* -*- C++ -*-
alpar@921:  * src/lemon/smart_graph.h - Part of LEMON, a generic C++ optimization library
alpar@906:  *
alpar@906:  * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
alpar@906:  * (Egervary Combinatorial Optimization Research Group, EGRES).
alpar@906:  *
alpar@906:  * Permission to use, modify and distribute this software is granted
alpar@906:  * provided that this copyright notice appears in all copies. For
alpar@906:  * precise terms see the accompanying LICENSE file.
alpar@906:  *
alpar@906:  * This software is provided "AS IS" with no warranty of any kind,
alpar@906:  * express or implied, and with no claim as to its suitability for any
alpar@906:  * purpose.
alpar@906:  *
alpar@906:  */
alpar@105: 
alpar@921: #ifndef LEMON_SMART_GRAPH_H
alpar@921: #define LEMON_SMART_GRAPH_H
alpar@104: 
klao@491: ///\ingroup graphs
alpar@242: ///\file
alpar@242: ///\brief SmartGraph and SymSmartGraph classes.
alpar@242: 
alpar@104: #include <vector>
alpar@104: 
alpar@921: #include <lemon/invalid.h>
alpar@157: 
klao@946: #include <lemon/clearable_graph_extender.h>
klao@946: #include <lemon/extendable_graph_extender.h>
klao@946: #include <lemon/iterable_graph_extender.h>
deba@1039: #include <lemon/alteration_notifier.h>
klao@946: #include <lemon/default_map.h>
klao@946: 
klao@1034: #include <lemon/undir_graph_extender.h>
klao@1034: 
klao@977: #include <lemon/utility.h>
deba@782: 
alpar@921: namespace lemon {
alpar@104: 
alpar@973:   class SmartGraph;
alpar@969:   ///Base of SmartGraph
alpar@969: 
alpar@969:   ///Base of SmartGraph
alpar@969:   ///
klao@946:   class SmartGraphBase {
alpar@104: 
alpar@973:     friend class SmatGraph;
alpar@973: 
alpar@973:   protected:
alpar@104:     struct NodeT 
alpar@104:     {
alpar@104:       int first_in,first_out;      
alpar@157:       NodeT() : first_in(-1), first_out(-1) {}
alpar@104:     };
alpar@104:     struct EdgeT 
alpar@104:     {
alpar@986:       int target, source, next_in, next_out;      
alpar@104:       //FIXME: is this necessary?
alpar@157:       EdgeT() : next_in(-1), next_out(-1) {}  
alpar@104:     };
alpar@104: 
alpar@104:     std::vector<NodeT> nodes;
alpar@129: 
alpar@104:     std::vector<EdgeT> edges;
alpar@104:     
alpar@185:     
alpar@104:   public:
deba@782: 
klao@946:     typedef SmartGraphBase Graph;
alpar@104: 
alpar@164:     class Node;
alpar@164:     class Edge;
alpar@108: 
alpar@104:     
alpar@104:   public:
alpar@104: 
klao@946:     SmartGraphBase() : nodes(), edges() { }
klao@946:     SmartGraphBase(const SmartGraphBase &_g) : nodes(_g.nodes), edges(_g.edges) { }
alpar@104:     
klao@977:     typedef True NodeNumTag;
klao@977:     typedef True EdgeNumTag;
klao@977: 
alpar@813:     ///Number of nodes.
alpar@813:     int nodeNum() const { return nodes.size(); }
alpar@813:     ///Number of edges.
alpar@813:     int edgeNum() const { return edges.size(); }
alpar@104: 
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; }
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@108: 
alpar@986:     Node source(Edge e) const { return edges[e.n].source; }
alpar@986:     Node target(Edge e) const { return edges[e.n].target; }
alpar@104: 
alpar@813:     /// Node ID.
alpar@813:     
alpar@813:     /// The ID of a valid Node is a nonnegative integer not greater than
alpar@813:     /// \ref maxNodeId(). The range of the ID's is not surely continuous
alpar@813:     /// and the greatest node ID can be actually less then \ref maxNodeId().
alpar@813:     ///
alpar@813:     /// The ID of the \ref INVALID node is -1.
alpar@813:     ///\return The ID of the node \c v. 
alpar@713:     static int id(Node v) { return v.n; }
alpar@813:     /// Edge ID.
alpar@813:     
alpar@813:     /// The ID of a valid Edge is a nonnegative integer not greater than
alpar@813:     /// \ref maxEdgeId(). The range of the ID's is not surely continuous
alpar@813:     /// and the greatest edge ID can be actually less then \ref maxEdgeId().
alpar@813:     ///
alpar@813:     /// The ID of the \ref INVALID edge is -1.
alpar@813:     ///\return The ID of the edge \c e. 
alpar@713:     static int id(Edge e) { return e.n; }
alpar@104: 
deba@1106:     static Node fromId(int id, Node) { return Node(id);}
deba@1106: 
deba@1106:     static Edge fromId(int id, Edge) { return Edge(id);}
deba@1106: 
alpar@164:     Node addNode() {
alpar@164:       Node n; n.n=nodes.size();
alpar@104:       nodes.push_back(NodeT()); //FIXME: Hmmm...
alpar@104:       return n;
alpar@104:     }
alpar@108:     
alpar@164:     Edge addEdge(Node u, Node v) {
alpar@164:       Edge e; e.n=edges.size(); edges.push_back(EdgeT()); //FIXME: Hmmm...
alpar@986:       edges[e.n].source=u.n; edges[e.n].target=v.n;
alpar@104:       edges[e.n].next_out=nodes[u.n].first_out;
alpar@104:       edges[e.n].next_in=nodes[v.n].first_in;
alpar@104:       nodes[u.n].first_out=nodes[v.n].first_in=e.n;
alpar@108: 
alpar@104:       return e;
alpar@104:     }
alpar@104: 
deba@782:     void clear() {
deba@782:       edges.clear();
deba@782:       nodes.clear();
deba@782:     }
alpar@104: 
klao@946: 
alpar@164:     class Node {
klao@946:       friend class SmartGraphBase;
alpar@973:       friend class SmartGraph;
alpar@104: 
alpar@104:     protected:
alpar@104:       int n;
alpar@973:       ///\todo It should be removed (or at least define a setToId() instead).
alpar@973:       ///
alpar@164:       Node(int nn) {n=nn;}
alpar@104:     public:
alpar@164:       Node() {}
alpar@503:       Node (Invalid) { n=-1; }
alpar@164:       bool operator==(const Node i) const {return n==i.n;}
alpar@164:       bool operator!=(const Node i) const {return n!=i.n;}
alpar@164:       bool operator<(const Node i) const {return n<i.n;}
alpar@104:     };
alpar@104:     
alpar@104: 
alpar@164:     class Edge {
klao@946:       friend class SmartGraphBase;
alpar@973:       friend class SmartGraph;
alpar@185: 
alpar@104:     protected:
alpar@104:       int n;
alpar@973:       ///\todo It should be removed (or at least define a setToId() instead).
alpar@973:       ///
alpar@905:       Edge(int nn) {n=nn;}
alpar@706:     public:
alpar@164:       Edge() { }
marci@174:       Edge (Invalid) { n=-1; }
alpar@164:       bool operator==(const Edge i) const {return n==i.n;}
alpar@164:       bool operator!=(const Edge i) const {return n!=i.n;}
alpar@164:       bool operator<(const Edge i) const {return n<i.n;}
klao@946:     };
alpar@905: 
klao@946:     void first(Node& node) const {
klao@946:       node.n = nodes.size() - 1;
klao@946:     }
klao@946: 
klao@946:     static void next(Node& node) {
klao@946:       --node.n;
klao@946:     }
klao@946: 
klao@946:     void first(Edge& edge) const {
klao@946:       edge.n = edges.size() - 1;
klao@946:     }
klao@946: 
klao@946:     static void next(Edge& edge) {
klao@946:       --edge.n;
klao@946:     }
klao@946: 
klao@946:     void firstOut(Edge& edge, const Node& node) const {
klao@946:       edge.n = nodes[node.n].first_out;
klao@946:     }
klao@946: 
klao@946:     void nextOut(Edge& edge) const {
klao@946:       edge.n = edges[edge.n].next_out;
klao@946:     }
klao@946: 
klao@946:     void firstIn(Edge& edge, const Node& node) const {
klao@946:       edge.n = nodes[node.n].first_in;
klao@946:     }
alpar@104:     
klao@946:     void nextIn(Edge& edge) const {
klao@946:       edge.n = edges[edge.n].next_in;
klao@946:     }
alpar@105: 
alpar@969:     Edge _findEdge(Node u,Node v, Edge prev = INVALID) 
alpar@969:     {
alpar@969:       int e = (prev.n==-1)? nodes[u.n].first_out : edges[prev.n].next_out;
alpar@1082:       while(e!=-1 && edges[e].target!=v.n) e = edges[e].next_out;
alpar@969:       prev.n=e;
alpar@969:       return prev;
alpar@969:     }
alpar@973: 
alpar@104:   };
alpar@185: 
klao@946:   typedef AlterableGraphExtender<SmartGraphBase> AlterableSmartGraphBase;
klao@946:   typedef IterableGraphExtender<AlterableSmartGraphBase> IterableSmartGraphBase;
deba@980:   typedef DefaultMappableGraphExtender<IterableSmartGraphBase> MappableSmartGraphBase;
klao@946:   typedef ExtendableGraphExtender<MappableSmartGraphBase> ExtendableSmartGraphBase;
klao@946:   typedef ClearableGraphExtender<ExtendableSmartGraphBase> ClearableSmartGraphBase;
deba@937: 
alpar@1161:   /// \addtogroup graphs
alpar@1161:   /// @{
alpar@1161: 
alpar@950:   ///A smart graph class.
deba@937: 
alpar@950:   ///This is a simple and fast graph implementation.
alpar@950:   ///It is also quite memory efficient, but at the price
alpar@974:   ///that <b> it does support only limited (only stack-like)
alpar@974:   ///node and edge deletions</b>.
alpar@950:   ///It conforms to 
klao@959:   ///the \ref concept::ExtendableGraph "ExtendableGraph" concept.
klao@959:   ///\sa concept::ExtendableGraph.
alpar@950:   ///
alpar@950:   ///\author Alpar Juttner
deba@980:   class SmartGraph : public ClearableSmartGraphBase {
alpar@969:   public:
alpar@969:     /// Finds an edge between two nodes.
alpar@973:     
alpar@969:     /// Finds an edge from node \c u to node \c v.
alpar@969:     ///
alpar@969:     /// If \c prev is \ref INVALID (this is the default value), then
alpar@969:     /// it finds the first edge from \c u to \c v. Otherwise it looks for
alpar@969:     /// the next edge from \c u to \c v after \c prev.
alpar@969:     /// \return The found edge or \ref INVALID if there is no such an edge.
alpar@969:     ///
alpar@969:     /// Thus you can iterate through each edge from \c u to \c v as it follows.
alpar@969:     /// \code
alpar@969:     /// for(Edge e=G.findEdge(u,v);e!=INVALID;e=G.findEdge(u,v,e)) {
alpar@969:     ///   ...
alpar@969:     /// }
alpar@969:     /// \endcode
alpar@969:     /// \todo Possibly it should be a global function.
alpar@969:     Edge findEdge(Node u,Node v, Edge prev = INVALID) 
alpar@969:     {
alpar@969:       return _findEdge(u,v,prev);
alpar@969:     }
alpar@973:     
alpar@1011:     class SnapShot;
alpar@1011:     friend class SnapShot;
alpar@973: 
alpar@1011:   protected:
alpar@1011:     void restoreSnapShot(const SnapShot &s)
alpar@973:     {
alpar@973:       while(s.edge_num>edges.size()) {
deba@1040: 	Parent::getNotifier(Edge()).erase(Edge(edges.size()-1));
alpar@986: 	nodes[edges.back().target].first_in=edges.back().next_in;
alpar@986: 	nodes[edges.back().source].first_out=edges.back().next_out;
alpar@973: 	edges.pop_back();
alpar@973:       }
alpar@973:       //nodes.resize(s.nodes_num);
alpar@973:       while(s.node_num>nodes.size()) {
deba@1040: 	Parent::getNotifier(Node()).erase(Node(nodes.size()-1));
alpar@973: 	nodes.pop_back();
alpar@973:       }
alpar@1011:     }    
alpar@1011: 
alpar@1011:   public:
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:     ///\note After you restore a state, you cannot restore
alpar@1011:     ///a later state, in other word you cannot add again the edges deleted
alpar@1011:     ///by restore() using another SnapShot instance.
alpar@1011:     ///
alpar@1011:     class SnapShot 
alpar@1011:     {
alpar@1011:       SmartGraph *g;
alpar@1011:     protected:
alpar@1011:       friend class SmartGraph;
alpar@1011:       unsigned int node_num;
alpar@1011:       unsigned int edge_num;
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(SmartGraph &_g) :g(&_g) {
alpar@1011: 	node_num=g->nodes.size();
alpar@1011: 	edge_num=g->edges.size();
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(SmartGraph &_g) 
alpar@1011:       {
alpar@1011: 	g=&_g;
alpar@1011: 	node_num=g->nodes.size();
alpar@1011: 	edge_num=g->edges.size();
alpar@1011:       }
alpar@1011: 
alpar@1011:       ///Undo the changes until a snapshot.
alpar@1011:       
alpar@1011:       ///Undo the changes until a snapshot created by save().
alpar@1011:       ///
alpar@1011:       ///\param s an internal stucture given back by save()
alpar@1011:       ///\note After you restored a state, you cannot restore
alpar@1011:       ///a later state, in other word you cannot add again the edges deleted
alpar@1011:       ///by restore().
alpar@1011:       ///
alpar@1011:       ///\todo This function might be called undo().
alpar@1011:       
alpar@1011:       void restore()
alpar@1011:       {
alpar@1011: 	g->restoreSnapShot(*this);
alpar@1011:       }
alpar@1011:     };
alpar@973:   };
klao@1034: 
klao@1034: 
klao@1034:   /**************** Undirected List Graph ****************/
klao@1034: 
klao@1034:   typedef ClearableUndirGraphExtender<
klao@1034:     ExtendableUndirGraphExtender<
klao@1034:     MappableUndirGraphExtender<
klao@1034:     IterableUndirGraphExtender<
klao@1034:     AlterableUndirGraphExtender<
klao@1034:     UndirGraphExtender<SmartGraphBase> > > > > > UndirSmartGraphBase;
klao@1034: 
alpar@1035:   ///A smart undirected graph class.
alpar@1035: 
alpar@1035:   ///This is a simple and fast undirected graph implementation.
alpar@1035:   ///It is also quite memory efficient, but at the price
alpar@1035:   ///that <b> it does support only limited (only stack-like)
alpar@1035:   ///node and edge deletions</b>.
alpar@1035:   ///Except from this it conforms to 
alpar@1035:   ///the \ref concept::UndirGraph "UndirGraph" concept.
alpar@1035:   ///\sa concept::UndirGraph.
alpar@1035:   ///
alpar@1035:   ///\todo SnapShot hasn't been implemented yet.
alpar@1035:   ///
klao@1034:   class UndirSmartGraph : public UndirSmartGraphBase {
klao@1034:   };
klao@1034: 
alpar@950:   
alpar@407:   /// @}  
alpar@921: } //namespace lemon
alpar@104: 
alpar@157: 
alpar@921: #endif //LEMON_SMART_GRAPH_H