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/idmappable_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: 
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@397:       int head, tail;
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 {
klao@946:       friend class Graph;
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 {
klao@946:       friend class Graph;
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)
alpar@813:     int maxNodeId() const { return nodes.size()-1; } 
klao@946: 
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@395: 
klao@946:     Node tail(Edge e) const { return edges[e.id].tail; }
klao@946:     Node head(Edge e) const { return edges[e.id].head; }
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;
klao@946: 	for(n = nodes[edges[edge.id].head].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:       
klao@946:       edges[n].tail = u.id; 
klao@946:       edges[n].head = 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 {
klao@946: 	nodes[edges[n].head].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 {
klao@946: 	nodes[edges[n].tail].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@949:     void _moveHead(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@949:       else nodes[edges[e.id].head].first_in = edges[e.id].next_in;
alpar@949:       edges[e.id].head = 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@949:     void _moveTail(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@949:       else nodes[edges[e.id].tail].first_out = edges[e.id].next_out;
alpar@949:       edges[e.id].tail = 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;
klao@946:   typedef IdMappableGraphExtender<IterableListGraphBase> IdMappableListGraphBase;
klao@946:   typedef DefaultMappableGraphExtender<IdMappableListGraphBase> 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@948:   ///It conforms to the
alpar@948:   ///\ref skeleton::ErasableGraph "ErasableGraph" concept.
alpar@948:   ///\sa skeleton::ErasableGraph.
deba@782: 
alpar@948:   class ListGraph : public ErasableListGraphBase 
alpar@948:   {
alpar@948:   public:
alpar@948:     /// Moves the head of \c e to \c n
alpar@948: 
alpar@948:     /// Moves the head of \c e to \c n
alpar@948:     ///
alpar@949:     void moveHead(Edge e, Node n) { _moveHead(e,n); }
alpar@948:     /// Moves the tail of \c e to \c n
alpar@948: 
alpar@948:     /// Moves the tail of \c e to \c n
alpar@948:     ///
alpar@949:     void moveTail(Edge e, Node n) { _moveTail(e,n); }
alpar@949: 
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@949:     
alpar@949:   };
alpar@949:   
alpar@948:   /// @}  
alpar@948: } //namespace lemon
klao@946:   
alpar@400: 
klao@946: #endif