source: lemon-0.x/lemon/full_bpugraph.h @ 2115:4cd528a30ec1

/* -*- 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_BPUGRAPH_H
#define LEMON_FULL_BPUGRAPH_H

#include <cmath>

#include <lemon/bits/bpugraph_extender.h>

#include <lemon/bits/invalid.h>
#include <lemon/bits/utility.h>


///\ingroup graphs
///\file
///\brief FullBpUGraph class.


namespace lemon {

  class FullBpUGraphBase {
  protected:

    int _aNodeNum;
    int _bNodeNum;

    int _edgeNum;

  public:

    class NodeSetError : public LogicError {
      virtual const char* exceptionName() const { 
        return "lemon::FullBpUGraph::NodeSetError";
      }
    };
  
    class Node {
      friend class FullBpUGraphBase;
    protected:
      int id;

      Node(int _id) : id(_id) {}
    public:
      Node() {}
      Node(Invalid) { id = -1; }
      bool operator==(const Node i) const {return id==i.id;}
      bool operator!=(const Node i) const {return id!=i.id;}
      bool operator<(const Node i) const {return id<i.id;}
    };

    class UEdge {
      friend class FullBpUGraphBase;
    protected:
      int id;

      UEdge(int _id) { id = _id;}
    public:
      UEdge() {}
      UEdge (Invalid) { id = -1; }
      bool operator==(const UEdge i) const {return id==i.id;}
      bool operator!=(const UEdge i) const {return id!=i.id;}
      bool operator<(const UEdge i) const {return id<i.id;}
    };

    void construct(int aNodeNum, int bNodeNum) {
      _aNodeNum = aNodeNum;
      _bNodeNum = bNodeNum;
      _edgeNum = aNodeNum * bNodeNum;
    }

    void firstANode(Node& node) const {
      node.id = 2 * _aNodeNum - 2;
      if (node.id < 0) node.id = -1; 
    }
    void nextANode(Node& node) const {
      node.id -= 2;
      if (node.id < 0) node.id = -1; 
    }

    void firstBNode(Node& node) const {
      node.id = 2 * _bNodeNum - 1;
    }
    void nextBNode(Node& node) const {
      node.id -= 2;
    }

    void first(Node& node) const {
      if (_aNodeNum > 0) {
        node.id = 2 * _aNodeNum - 2;
      } else {
        node.id = 2 * _bNodeNum - 1;
      }
    }
    void next(Node& node) const {
      node.id -= 2;
      if (node.id == -2) {
        node.id = 2 * _bNodeNum - 1;
      }
    }
  
    void first(UEdge& edge) const {
      edge.id = _edgeNum - 1;
    }
    void next(UEdge& edge) const {
      --edge.id;
    }

    void firstFromANode(UEdge& edge, const Node& node) const {
      LEMON_ASSERT((node.id & 1) == 0, NodeSetError());
      edge.id = (node.id >> 1) * _bNodeNum;
    }
    void nextFromANode(UEdge& edge) const {
      ++(edge.id);
      if (edge.id % _bNodeNum == 0) edge.id = -1;
    }

    void firstFromBNode(UEdge& edge, const Node& node) const {
      LEMON_ASSERT((node.id & 1) == 1, NodeSetError());
      edge.id = (node.id >> 1);
    }
    void nextFromBNode(UEdge& edge) const {
      edge.id += _bNodeNum;
      if (edge.id >= _edgeNum) edge.id = -1;
    }

    static int id(const Node& node) {
      return node.id;
    }
    static Node nodeFromId(int id) {
      return Node(id);
    }
    int maxNodeId() const {
      return _aNodeNum > _bNodeNum ? 
        _aNodeNum * 2 - 2 : _bNodeNum * 2 - 1;
    }
  
    static int id(const UEdge& edge) {
      return edge.id;
    }
    static UEdge uEdgeFromId(int id) {
      return UEdge(id);
    }
    int maxUEdgeId() const {
      return _edgeNum - 1;
    }
  
    static int aNodeId(const Node& node) {
      return node.id >> 1;
    }
    static Node fromANodeId(int id) {
      return Node(id << 1);
    }
    int maxANodeId() const {
      return _aNodeNum;
    }

    static int bNodeId(const Node& node) {
      return node.id >> 1;
    }
    static Node fromBNodeId(int id) {
      return Node((id << 1) + 1);
    }
    int maxBNodeId() const {
      return _bNodeNum;
    }

    Node aNode(const UEdge& edge) const {
      return Node((edge.id / _bNodeNum) << 1);
    }
    Node bNode(const UEdge& edge) const {
      return Node(((edge.id % _bNodeNum) << 1) + 1);
    }

    static bool aNode(const Node& node) {
      return (node.id & 1) == 0;
    }

    static bool bNode(const Node& node) {
      return (node.id & 1) == 1;
    }

    static Node aNode(int index) {
      return Node(index << 1);
    }

    static Node bNode(int index) {
      return Node((index << 1) + 1);
    }

    typedef True NodeNumTag;
    int nodeNum() const { return _aNodeNum + _bNodeNum; }
    int aNodeNum() const { return _aNodeNum; }
    int bNodeNum() const { return _bNodeNum; }

    typedef True EdgeNumTag;
    int uEdgeNum() const { return _edgeNum; }

  };


  typedef BpUGraphExtender<FullBpUGraphBase> ExtendedFullBpUGraphBase;


  /// \ingroup graphs
  ///
  /// \brief An undirected full bipartite graph class.
  ///
  /// This is a simple and fast bipartite undirected full graph implementation.
  /// It is completely static, so you can neither add nor delete either
  /// edges or nodes.
  ///
  /// \sa FullUGraphBase
  /// \sa FullGraph
  ///
  /// \author Balazs Dezso
  class FullBpUGraph : 
    public ExtendedFullBpUGraphBase {
  public:

    typedef ExtendedFullBpUGraphBase Parent;

    FullBpUGraph() {
      Parent::construct(0, 0);
    }

    FullBpUGraph(int aNodeNum, int bNodeNum) {
      Parent::construct(aNodeNum, bNodeNum);
    }

    /// \brief Resize the graph
    ///
    void resize(int n, int m) {
      Parent::getNotifier(Edge()).clear();
      Parent::getNotifier(UEdge()).clear();
      Parent::getNotifier(Node()).clear();
      Parent::getNotifier(ANode()).clear();
      Parent::getNotifier(BNode()).clear();
      construct(n, m);
      Parent::getNotifier(ANode()).build();
      Parent::getNotifier(BNode()).build();
      Parent::getNotifier(Node()).build();
      Parent::getNotifier(UEdge()).build();
      Parent::getNotifier(Edge()).build();
    }
  };

} //namespace lemon


#endif //LEMON_FULL_GRAPH_H