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/erasable_graph_extender.h>
klao@946: #include <lemon/clearable_graph_extender.h>
klao@946: #include <lemon/extendable_graph_extender.h>
deba@937: 
klao@946: #include <lemon/idmappable_graph_extender.h>
alpar@919: 
klao@946: #include <lemon/iterable_graph_extender.h>
deba@782: 
klao@946: #include <lemon/alteration_observer_registry.h>
klao@946: #include <lemon/default_map.h>
klao@946: 
klao@946: 
klao@946: #include <lemon/graph_utils.h>
klao@946: 
deba@782: 
alpar@921: namespace lemon {
alpar@104: 
klao@946:   /// \addtogroup graphs
klao@946:   /// @{
alpar@185: 
alpar@969:   ///Base of SmartGraph
alpar@969: 
alpar@969:   ///Base of SmartGraph
alpar@969:   ///
klao@946:   class SmartGraphBase {
alpar@104: 
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@104:       int head, tail, 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:     
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)
alpar@813:     int maxNodeId() const { return nodes.size()-1; }
alpar@813:     /// Maximum edge ID.
alpar@813:     
alpar@813:     /// Maximum edge ID.
alpar@813:     ///\sa id(Edge)
alpar@813:     int maxEdgeId() const { return edges.size()-1; }
alpar@108: 
alpar@164:     Node tail(Edge e) const { return edges[e.n].tail; }
alpar@164:     Node head(Edge e) const { return edges[e.n].head; }
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: 
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@104:       edges[e.n].tail=u.n; edges[e.n].head=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@104: 
alpar@104:     protected:
alpar@104:       int n;
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@185: 
alpar@104:     protected:
alpar@104:       int n;
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@969:       while(e!=-1 && edges[e].tail!=v.n) e = edges[e].next_out;
alpar@969:       prev.n=e;
alpar@969:       return prev;
alpar@969:     }
alpar@104:   };
alpar@185: 
klao@946:   typedef AlterableGraphExtender<SmartGraphBase> AlterableSmartGraphBase;
klao@946:   typedef IterableGraphExtender<AlterableSmartGraphBase> IterableSmartGraphBase;
klao@946:   typedef IdMappableGraphExtender<IterableSmartGraphBase> IdMappableSmartGraphBase;
klao@946:   typedef DefaultMappableGraphExtender<IdMappableSmartGraphBase> MappableSmartGraphBase;
klao@946:   typedef ExtendableGraphExtender<MappableSmartGraphBase> ExtendableSmartGraphBase;
klao@946:   typedef ClearableGraphExtender<ExtendableSmartGraphBase> ClearableSmartGraphBase;
deba@937: 
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@950:   ///that <b> it does not support node and edge deletion</b>.
alpar@950:   ///It conforms to 
klao@959:   ///the \ref concept::ExtendableGraph "ExtendableGraph" concept.
klao@959:   ///\sa concept::ExtendableGraph.
alpar@950:   ///
alpar@950:   ///\todo Some member functions could be \c static.
alpar@950:   ///
alpar@950:   ///\todo A possibly useful functionality: a function saveState()
alpar@950:   ///(or snapshot() ) would
alpar@950:   ///give back a data sturcture X and then the function restoreState(X)
alpar@950:   ///(or rollBack() )
alpar@950:   ///would remove the nodes and edges added after the call of saveState().
alpar@950:   ///Of course it should be used as a stack. (Maybe X is not necessary.)
alpar@950:   ///
alpar@950:   ///\author Alpar Juttner
alpar@969:   class SmartGraph :public ClearableSmartGraphBase {
alpar@969:   public:
alpar@969:     /// Finds an edge between two nodes.
alpar@969: 
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@969: };
alpar@950:   
klao@946:   template <>
klao@946:   int countNodes<SmartGraph>(const SmartGraph& graph) {
klao@946:     return graph.nodeNum();
klao@946:   }
deba@937: 
klao@946:   template <>
klao@946:   int countEdges<SmartGraph>(const SmartGraph& graph) {
klao@946:     return graph.edgeNum();
klao@946:   }
deba@937: 
alpar@407:   /// @}  
alpar@921: } //namespace lemon
alpar@104: 
alpar@157: 
alpar@157: 
alpar@157: 
alpar@921: #endif //LEMON_SMART_GRAPH_H