/* -*- C++ -*-

  *

  * This file is a part of LEMON, a generic C++ optimization library

  *

  * Copyright (C) 2003-2006

  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

  * (Egervary Research Group on Combinatorial Optimization, EGRES).

  *

  * Permission to use, modify and distribute this software is granted

  * provided that this copyright notice appears in all copies. For

  * precise terms see the accompanying LICENSE file.

  *

  * This software is provided "AS IS" with no warranty of any kind,

  * express or implied, and with no claim as to its suitability for any

  * purpose.

  *

  */

 #ifndef LEMON_FULL_GRAPH_H

 #define LEMON_FULL_GRAPH_H

 #include <cmath>

 #include <lemon/bits/graph_extender.h>

 #include <lemon/bits/invalid.h>

 #include <lemon/bits/utility.h>

 ///\ingroup graphs

 ///\file

 ///\brief FullGraph class.

 namespace lemon {

   /// \brief Base of the FullGrpah.

   ///

   /// Base of the FullGrpah.

   class FullGraphBase {

     int _nodeNum;

     int _edgeNum;

   public:

     typedef FullGraphBase Graph;

     class Node;

     class Edge;

   public:

     FullGraphBase() {}

     ///Creates a full graph with \c n nodes.

     void construct(int n) { _nodeNum = n; _edgeNum = n * n; }

     typedef True NodeNumTag;

     typedef True EdgeNumTag;

     /// \brief Returns the node with the given index.

     ///

     /// Returns the node with the given index. Because it is a

     /// static size graph the node's of the graph can be indiced

     /// by the range from 0 to \e nodeNum()-1 and the index of

     /// the node can accessed by the \e index() member.

     Node operator()(int index) const { return Node(index); }

     /// \brief Returns the index of the node.

     ///

     /// Returns the index of the node. Because it is a

     /// static size graph the node's of the graph can be indiced

     /// by the range from 0 to \e nodeNum()-1 and the index of

     /// the node can accessed by the \e index() member.

     int index(const Node& node) const { return node.id; }

     ///Number of nodes.

     int nodeNum() const { return _nodeNum; }

     ///Number of edges.

     int edgeNum() const { return _edgeNum; }

     /// Maximum node ID.

     /// Maximum node ID.

     ///\sa id(Node)

     int maxNodeId() const { return _nodeNum-1; }

     /// Maximum edge ID.

     /// Maximum edge ID.

     ///\sa id(Edge)

     int maxEdgeId() const { return _edgeNum-1; }

     Node source(Edge e) const { return e.id % _nodeNum; }

     Node target(Edge e) const { return e.id / _nodeNum; }

     /// Node ID.

     /// The ID of a valid Node is a nonnegative integer not greater than

     /// \ref maxNodeId(). The range of the ID's is not surely continuous

     /// and the greatest node ID can be actually less then \ref maxNodeId().

     ///

     /// The ID of the \ref INVALID node is -1.

     ///\return The ID of the node \c v. 

     static int id(Node v) { return v.id; }

     /// Edge ID.

     /// The ID of a valid Edge is a nonnegative integer not greater than

     /// \ref maxEdgeId(). The range of the ID's is not surely continuous

     /// and the greatest edge ID can be actually less then \ref maxEdgeId().

     ///

     /// The ID of the \ref INVALID edge is -1.

     ///\return The ID of the edge \c e. 

     static int id(Edge e) { return e.id; }

     static Node nodeFromId(int id) { return Node(id);}

     static Edge edgeFromId(int id) { return Edge(id);}

     typedef True FindEdgeTag;

     /// Finds an edge between two nodes.

     /// Finds an edge from node \c u to node \c v.

     ///

     /// If \c prev is \ref INVALID (this is the default value), then

     /// It finds the first edge from \c u to \c v. Otherwise it looks for

     /// the next edge from \c u to \c v after \c prev.

     /// \return The found edge or INVALID if there is no such an edge.

     Edge findEdge(Node u,Node v, Edge prev = INVALID) const {

       return prev.id == -1 ? Edge(*this, u.id, v.id) : INVALID;

     }

     class Node {

       friend class FullGraphBase;

     protected:

       int id;

       Node(int _id) : id(_id) {}

     public:

       Node() {}

       Node (Invalid) : id(-1) {}

       bool operator==(const Node node) const {return id == node.id;}

       bool operator!=(const Node node) const {return id != node.id;}

       bool operator<(const Node node) const {return id < node.id;}

     };

     class Edge {

       friend class FullGraphBase;

     protected:

       int id;  // _nodeNum * target + source;

       Edge(int _id) : id(_id) {}

       Edge(const FullGraphBase& _graph, int source, int target) 

 	: id(_graph._nodeNum * target+source) {}

     public:

       Edge() { }

       Edge (Invalid) { id = -1; }

       bool operator==(const Edge edge) const {return id == edge.id;}

       bool operator!=(const Edge edge) const {return id != edge.id;}

       bool operator<(const Edge edge) const {return id < edge.id;}

     };

     void first(Node& node) const {

       node.id = _nodeNum-1;

     }

     static void next(Node& node) {

       --node.id;

     }

     void first(Edge& edge) const {

       edge.id = _edgeNum-1;

     }

     static void next(Edge& edge) {

       --edge.id;

     }

     void firstOut(Edge& edge, const Node& node) const {

       edge.id = _edgeNum + node.id - _nodeNum;

     }

     void nextOut(Edge& edge) const {

       edge.id -= _nodeNum;

       if (edge.id < 0) edge.id = -1;

     }

     void firstIn(Edge& edge, const Node& node) const {

       edge.id = node.id * _nodeNum;

     }

     void nextIn(Edge& edge) const {

       ++edge.id;

       if (edge.id % _nodeNum == 0) edge.id = -1;

     }

   };

   typedef GraphExtender<FullGraphBase> ExtendedFullGraphBase;

   /// \ingroup graphs

   ///

   /// \brief A full graph class.

   ///

   /// This is a simple and fast directed full graph implementation.

   /// It is completely static, so you can neither add nor delete either

   /// edges or nodes.

   /// Thus it conforms to

   /// the \ref concept::Graph "Graph" concept

   /// \sa concept::Graph.

   ///

   /// \sa FullGraphBase

   /// \sa FullUGraph

   ///

   /// \author Alpar Juttner

   class FullGraph : public ExtendedFullGraphBase {

   public:

     typedef ExtendedFullGraphBase Parent;

     /// \brief Constructor

     FullGraph() { construct(0); }

     /// \brief Constructor

     ///

     FullGraph(int n) { construct(n); }

     /// \brief Resize the graph

     ///

     /// Resize the graph. The function will fully destroy and build the graph.

     /// This cause that the maps of the graph will reallocated

     /// automatically and the previous values will be lost.

     void resize(int n) {

       Parent::getNotifier(Edge()).clear();

       Parent::getNotifier(Node()).clear();

       construct(n);

       Parent::getNotifier(Node()).build();

       Parent::getNotifier(Edge()).build();

     }

   };

 } //namespace lemon

 #endif //LEMON_FULL_GRAPH_H