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>
deba@782: #include <climits>
alpar@104: 
alpar@921: #include <lemon/invalid.h>
alpar@157: 
alpar@921: #include <lemon/array_map.h>
alpar@921: #include <lemon/sym_map.h>
alpar@919: 
alpar@921: #include <lemon/map_registry.h>
deba@782: 
alpar@921: #include <lemon/map_defines.h>
deba@782: 
alpar@921: namespace lemon {
alpar@104: 
alpar@407: /// \addtogroup graphs
alpar@407: /// @{
deba@782: //  class SymSmartGraph;
alpar@185: 
alpar@186:   ///A smart graph class.
alpar@186: 
alpar@186:   ///This is a simple and fast graph implementation.
alpar@186:   ///It is also quite memory efficient, but at the price
alpar@186:   ///that <b> it does not support node and edge deletion</b>.
alpar@880:   ///It conforms to 
alpar@880:   ///the \ref skeleton::ExtendableGraph "ExtendableGraph" concept.
alpar@880:   ///\sa skeleton::ExtendableGraph.
alpar@402:   ///
alpar@402:   ///\todo Some member functions could be \c static.
alpar@753:   ///
alpar@753:   ///\todo A possibly useful functionality: a function saveState() would
alpar@753:   ///give back a data sturcture X and then the function restoreState(X)
alpar@753:   ///would remove the nodes and edges added after the call of saveState().
alpar@753:   ///Of course it should be used as a stack. (Maybe X is not necessary.)
alpar@753:   ///
alpar@456:   ///\author Alpar Juttner
alpar@104:   class SmartGraph {
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: 
deba@782:     typedef SmartGraph Graph;
alpar@104: 
alpar@164:     class Node;
alpar@164:     class Edge;
alpar@108: 
alpar@164:     class NodeIt;
alpar@164:     class EdgeIt;
alpar@104:     class OutEdgeIt;
alpar@104:     class InEdgeIt;
alpar@104:     
alpar@904:     // Create map registries.
deba@782:     CREATE_MAP_REGISTRIES;
alpar@904:     // Create node and edge maps.
deba@897:     CREATE_MAPS(ArrayMap);
alpar@104:     
alpar@104:   public:
alpar@104: 
alpar@104:     SmartGraph() : nodes(), edges() { }
alpar@136:     SmartGraph(const SmartGraph &_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@164:     NodeIt& first(NodeIt& v) const { 
alpar@164:       v=NodeIt(*this); return v; }
alpar@164:     EdgeIt& first(EdgeIt& e) const { 
alpar@164:       e=EdgeIt(*this); return e; }
alpar@164:     OutEdgeIt& first(OutEdgeIt& e, const Node v) const { 
alpar@104:       e=OutEdgeIt(*this,v); return e; }
alpar@164:     InEdgeIt& first(InEdgeIt& e, const Node v) const { 
alpar@104:       e=InEdgeIt(*this,v); return e; }
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@108: 
deba@782:       
deba@782:       node_maps.add(n);
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: 
deba@782:       edge_maps.add(e);
alpar@108: 
alpar@104:       return e;
alpar@104:     }
alpar@104: 
alpar@774:     /// Finds an edge between two nodes.
alpar@774: 
alpar@774:     /// Finds an edge from node \c u to node \c v.
alpar@774:     ///
alpar@774:     /// If \c prev is \ref INVALID (this is the default value), then
alpar@774:     /// It finds the first edge from \c u to \c v. Otherwise it looks for
alpar@774:     /// the next edge from \c u to \c v after \c prev.
alpar@774:     /// \return The found edge or INVALID if there is no such an edge.
alpar@774:     Edge findEdge(Node u,Node v, Edge prev = INVALID) 
alpar@774:     {
alpar@774:       int e = (prev.n==-1)? nodes[u.n].first_out : edges[prev.n].next_out;
alpar@774:       while(e!=-1 && edges[e].tail!=v.n) e = edges[e].next_out;
alpar@774:       prev.n=e;
alpar@774:       return prev;
alpar@774:     }
alpar@774:     
deba@782:     void clear() {
deba@782:       edge_maps.clear();
deba@782:       edges.clear();
deba@782:       node_maps.clear();
deba@782:       nodes.clear();
deba@782:     }
alpar@104: 
alpar@164:     class Node {
alpar@104:       friend class SmartGraph;
alpar@104:       template <typename T> friend class NodeMap;
alpar@104:       
alpar@164:       friend class Edge;
alpar@104:       friend class OutEdgeIt;
alpar@104:       friend class InEdgeIt;
alpar@164:       friend class SymEdge;
alpar@104: 
alpar@104:     protected:
alpar@104:       int n;
alpar@722:       friend int SmartGraph::id(Node v); 
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@774:       //      ///Validity check
alpar@774:       //      operator bool() { return n!=-1; }
alpar@104:     };
alpar@104:     
alpar@164:     class NodeIt : public Node {
alpar@774:       const SmartGraph *G;
alpar@104:       friend class SmartGraph;
alpar@104:     public:
alpar@402:       NodeIt() : Node() { }
alpar@774:       NodeIt(const SmartGraph& _G,Node n) : Node(n), G(&_G) { }
alpar@402:       NodeIt(Invalid i) : Node(i) { }
alpar@774:       NodeIt(const SmartGraph& _G) : Node(_G.nodes.size()?0:-1), G(&_G) { }
alpar@774:       NodeIt &operator++() {
alpar@774: 	n=(n+2)%(G->nodes.size()+1)-1; 
alpar@774: 	return *this; 
alpar@774:       }
alpar@774: //       ///Validity check
alpar@774: //       operator bool() { return Node::operator bool(); }      
alpar@104:     };
alpar@104: 
alpar@164:     class Edge {
alpar@104:       friend class SmartGraph;
alpar@104:       template <typename T> friend class EdgeMap;
alpar@185: 
alpar@905:       friend class SymSmartGraph;
alpar@104:       
alpar@164:       friend class Node;
alpar@104:       friend class NodeIt;
alpar@104:     protected:
alpar@104:       int n;
alpar@722:       friend int SmartGraph::id(Edge e);
alpar@905:       Edge(int nn) {n=nn;}
alpar@706:     public:
alpar@706:       /// An Edge with id \c n.
alpar@706: 
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;}
alpar@774: //       ///Validity check
alpar@774: //       operator bool() { return n!=-1; }
alpar@905: 
alpar@905:       ///Set the edge to that have ID \c ID.
alpar@905:       void setToId(int id) { n=id; }
alpar@774:    };
alpar@104:     
alpar@164:     class EdgeIt : public Edge {
alpar@774:       const SmartGraph *G;
alpar@104:       friend class SmartGraph;
alpar@104:     public:
alpar@774:       EdgeIt(const SmartGraph& _G) : Edge(_G.edges.size()-1), G(&_G) { }
alpar@774:       EdgeIt(const SmartGraph& _G, Edge e) : Edge(e), G(&_G) { }
alpar@164:       EdgeIt (Invalid i) : Edge(i) { }
alpar@164:       EdgeIt() : Edge() { }
alpar@774:       EdgeIt &operator++() { --n; return *this; }
alpar@774: //       ///Validity check
alpar@774: //       operator bool() { return Edge::operator bool(); }      
alpar@104:     };
alpar@104:     
alpar@164:     class OutEdgeIt : public Edge {
alpar@774:       const SmartGraph *G;
alpar@104:       friend class SmartGraph;
alpar@104:     public: 
alpar@164:       OutEdgeIt() : Edge() { }
alpar@774:       OutEdgeIt(const SmartGraph& _G, Edge e) : Edge(e), G(&_G) { }
alpar@164:       OutEdgeIt (Invalid i) : Edge(i) { }
alpar@157: 
alpar@774:       OutEdgeIt(const SmartGraph& _G,const Node v)
alpar@774: 	: Edge(_G.nodes[v.n].first_out), G(&_G) {}
alpar@774:       OutEdgeIt &operator++() { n=G->edges[n].next_out; return *this; }
alpar@774: //       ///Validity check
alpar@774: //       operator bool() { return Edge::operator bool(); }      
alpar@104:     };
alpar@104:     
alpar@164:     class InEdgeIt : public Edge {
alpar@774:       const SmartGraph *G;
alpar@104:       friend class SmartGraph;
alpar@104:     public: 
alpar@164:       InEdgeIt() : Edge() { }
alpar@774:       InEdgeIt(const SmartGraph& _G, Edge e) : Edge(e), G(&_G) { }
alpar@164:       InEdgeIt (Invalid i) : Edge(i) { }
alpar@774:       InEdgeIt(const SmartGraph& _G,Node v)
alpar@774: 	: Edge(_G.nodes[v.n].first_in), G(&_G) { }
alpar@774:       InEdgeIt &operator++() { n=G->edges[n].next_in; return *this; }
alpar@774: //       ///Validity check
alpar@774: //       operator bool() { return Edge::operator bool(); }      
alpar@104:     };
alpar@105: 
alpar@104:   };
alpar@185: 
alpar@185:   ///Graph for bidirectional edges.
alpar@185: 
alpar@185:   ///The purpose of this graph structure is to handle graphs
alpar@185:   ///having bidirectional edges. Here the function \c addEdge(u,v) adds a pair
alpar@186:   ///of oppositely directed edges.
alpar@186:   ///There is a new edge map type called
alpar@186:   ///\ref SymSmartGraph::SymEdgeMap "SymEdgeMap"
alpar@186:   ///that complements this
alpar@186:   ///feature by
alpar@186:   ///storing shared values for the edge pairs. The usual
alpar@880:   ///\ref Graph::EdgeMap "EdgeMap"
alpar@186:   ///can be used
alpar@185:   ///as well.
alpar@185:   ///
alpar@186:   ///The oppositely directed edge can also be obtained easily
alpar@186:   ///using \ref opposite.
alpar@186:   ///\warning It shares the similarity with \ref SmartGraph that
alpar@186:   ///it is not possible to delete edges or nodes from the graph.
alpar@880:   //\sa SmartGraph.
alpar@185: 
alpar@919:   class SymSmartGraph : public SmartGraph
alpar@185:   {
alpar@185:   public:
deba@782:     typedef SymSmartGraph Graph;
deba@782: 
alpar@904:     // Create symmetric map registry.
deba@782:     CREATE_SYM_EDGE_MAP_REGISTRY;
alpar@904:     // Create symmetric edge map.
deba@897:     CREATE_SYM_EDGE_MAP(ArrayMap);
deba@822: 
alpar@186: 
alpar@185:     SymSmartGraph() : SmartGraph() { }
alpar@185:     SymSmartGraph(const SmartGraph &_g) : SmartGraph(_g) { }
alpar@398:     ///Adds a pair of oppositely directed edges to the graph.
alpar@185:     Edge addEdge(Node u, Node v)
alpar@185:     {
alpar@185:       Edge e = SmartGraph::addEdge(u,v);
deba@798:       Edge f = SmartGraph::addEdge(v,u);
deba@798:       sym_edge_maps.add(e);
deba@798:       sym_edge_maps.add(f);
alpar@185:       return e;
alpar@185:     }
alpar@185: 
alpar@186:     ///The oppositely directed edge.
alpar@186: 
alpar@186:     ///Returns the oppositely directed
alpar@186:     ///pair of the edge \c e.
alpar@713:     static Edge opposite(Edge e)
alpar@185:     {
alpar@185:       Edge f;
alpar@905:       f.n = e.n - 2*(e.n%2) + 1;
alpar@185:       return f;
alpar@185:     }
alpar@185:     
alpar@185: 
alpar@919:   };
alpar@185:   
alpar@407:   /// @}  
alpar@921: } //namespace lemon
alpar@104: 
alpar@157: 
alpar@157: 
alpar@157: 
alpar@921: #endif //LEMON_SMART_GRAPH_H