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Changeset 803:c3d832275e69 in lemon-0.x for src/hugo/skeletons


Ignore:
Timestamp:
09/05/04 22:13:48 (20 years ago)
Author:
Alpar Juttner
Branch:
default
Phase:
public
Convert:
svn:c9d7d8f5-90d6-0310-b91f-818b3a526b0e/lemon/trunk@1097
Message:
  • Clarified Path skeleton.
  • setStart() changed to setStartNode()
File:
1 edited

Legend:

Unmodified
Added
Removed

  • src/hugo/skeletons/path.h

    r797 r803  
    3131
    3232namespace hugo {
    33 
    34   /// \addtogroup paths
    35   /// @{
    36 
    37 
    38   //! \brief A structure for representing directed path in a graph.
    39   //!
    40   //! A structure for representing directed path in a graph.
    41   //! \param Graph The graph type in which the path is.
    42   //! \param DM DebugMode, defaults to DefaultDebugMode.
    43   //!
    44   //! In a sense, the path can be treated as a graph, for is has \c NodeIt
    45   //! and \c EdgeIt with the same usage. These types converts to the \c Node
    46   //! and \c Edge of the original graph.
    47   //!
    48   //! \todo Thoroughfully check all the range and consistency tests.
    49   template<typename Graph, typename DM = DefaultDebugMode>
    50   class DirPath {
    51   public:
    52     /// Edge type of the underlying graph.
    53     typedef typename Graph::Edge GraphEdge;
    54     /// Node type of the underlying graph.
    55     typedef typename Graph::Node GraphNode;
    56     class NodeIt;
    57     class EdgeIt;
    58 
    59   protected:
    60     const Graph *gr;
    61     typedef std::vector<GraphEdge> Container;
    62     Container edges;
    63 
    64   public:
    65 
    66     /// \param _G The graph in which the path is.
    67     ///
    68     DirPath(const Graph &_G) : gr(&_G) {}
    69 
    70     /// \brief Subpath constructor.
    71     ///
    72     /// Subpath defined by two nodes.
    73     /// \warning It is an error if the two edges are not in order!
    74     DirPath(const DirPath &P, const NodeIt &a, const NodeIt &b) {
    75       if( DM::range_check && (!a.valid() || !b.valid) ) {
    76         // FIXME: this check should be more elaborate...
    77         fault("DirPath, subpath ctor: invalid bounding nodes");
    78       }
    79       gr = P.gr;
    80       edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx);
    81     }
    82 
    83     /// \brief Subpath constructor.
    84     ///
    85     /// Subpath defined by two edges. Contains edges in [a,b)
    86     /// \warning It is an error if the two edges are not in order!
    87     DirPath(const DirPath &P, const EdgeIt &a, const EdgeIt &b) {
    88       if( DM::range_check && (!a.valid() || !b.valid) ) {
    89         // FIXME: this check should be more elaborate...
    90         fault("DirPath, subpath ctor: invalid bounding nodes");
    91       }
    92       gr = P.gr;
    93       edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx);
    94     }
    95 
    96     /// Length of the path.
    97     size_t length() const { return edges.size(); }
    98     /// Returns whether the path is empty.
    99     bool empty() const { return edges.empty(); }
    100 
    101     /// Resets the path to an empty path.
    102     void clear() { edges.clear(); }
    103 
    104     /// \brief Starting point of the path.
    105     ///
    106     /// Starting point of the path.
    107     /// Returns INVALID if the path is empty.
    108     GraphNode from() const {
    109       return empty() ? INVALID : gr->tail(edges[0]);
    110     }
    111     /// \brief End point of the path.
    112     ///
    113     /// End point of the path.
    114     /// Returns INVALID if the path is empty.
    115     GraphNode to() const {
    116       return empty() ? INVALID : gr->head(edges[length()-1]);
    117     }
    118 
    119     /// \brief Initializes node or edge iterator to point to the first
    120     /// node or edge.
    121     ///
    122     /// \sa nth
    123     template<typename It>
    124     It& first(It &i) const { return i=It(*this); }
    125 
    126     /// \brief Initializes node iterator to point to the node of a given index.
    127     NodeIt& nth(NodeIt &i, int n) const {
    128       if( DM::range_check && (n<0 || n>int(length())) )
    129         fault("DirPath::nth: index out of range");
    130       return i=NodeIt(*this, n);
    131     }
    132 
    133     /// \brief Initializes edge iterator to point to the edge of a given index.
    134     EdgeIt& nth(EdgeIt &i, int n) const {
    135       if( DM::range_check && (n<0 || n>=int(length())) )
    136         fault("DirPath::nth: index out of range");
    137       return i=EdgeIt(*this, n);
    138     }
    139 
    140     /// Checks validity of a node or edge iterator.
    141     template<typename It>
    142     static
    143     bool valid(const It &i) { return i.valid(); }
    144 
    145     /// Steps the given node or edge iterator.
    146     template<typename It>
    147     static
    148     It& next(It &e) {
    149       if( DM::range_check && !e.valid() )
    150         fault("DirPath::next() on invalid iterator");
    151       return ++e;
    152     }
    153 
    154     /// \brief Returns node iterator pointing to the head node of the
    155     /// given edge iterator.
    156     NodeIt head(const EdgeIt& e) const {
    157       if( DM::range_check && !e.valid() )
    158         fault("DirPath::head() on invalid iterator");
    159       return NodeIt(*this, e.idx+1);
    160     }
    161 
    162     /// \brief Returns node iterator pointing to the tail node of the
    163     /// given edge iterator.
    164     NodeIt tail(const EdgeIt& e) const {
    165       if( DM::range_check && !e.valid() )
    166         fault("DirPath::tail() on invalid iterator");
    167       return NodeIt(*this, e.idx);
    168     }
    169 
    170 
    171     /* Iterator classes */
    172 
    173     /**
    174      * \brief Iterator class to iterate on the edges of the paths
    175      *
    176      * \ingroup paths
    177      * This class is used to iterate on the edges of the paths
    178      *
    179      * Of course it converts to Graph::Edge
    180      *
    181      * \todo Its interface differs from the standard edge iterator.
    182      * Yes, it shouldn't.
    183      */
    184     class EdgeIt {
    185       friend class DirPath;
    186 
    187       int idx;
    188       const DirPath *p;
     33  namespace skeleton {
     34    /// \addtogroup skeletons
     35    /// @{
     36   
     37   
     38    //! \brief A structure for representing directed path in a graph.
     39    //!
     40    //! A structure for representing directed path in a graph.
     41    //! \param GR The graph type in which the path is.
     42    //!
     43    //! In a sense, the path can be treated as a graph, for is has \c NodeIt
     44    //! and \c EdgeIt with the same usage. These types converts to the \c Node
     45    //! and \c Edge of the original graph.
     46    template<typename GR>
     47    class Path {
    18948    public:
    190       /// Default constructor
    191       EdgeIt() {}
    192       /// Invalid constructor
    193       EdgeIt(Invalid) : idx(-1), p(0) {}
    194       /// Constructor with starting point
    195       EdgeIt(const DirPath &_p, int _idx = 0) :
    196         idx(_idx), p(&_p) { validate(); }
    197 
    198       ///Validity check
    199       bool valid() const { return idx!=-1; }
    200 
    201       ///Conversion to Graph::Edge
    202       operator GraphEdge () const {
    203         return valid() ? p->edges[idx] : INVALID;
    204       }
    205 
    206       /// Next edge
    207       EdgeIt& operator++() { ++idx; validate(); return *this; }
    208 
    209       /// Comparison operator
    210       bool operator==(const EdgeIt& e) const { return idx==e.idx; }
    211       /// Comparison operator
    212       bool operator!=(const EdgeIt& e) const { return idx!=e.idx; }
    213       /// Comparison operator
    214       bool operator<(const EdgeIt& e) const { return idx<e.idx; }
    215 
    216     private:
    217       // FIXME: comparison between signed and unsigned...
    218       // Jo ez igy? Vagy esetleg legyen a length() int?
    219       void validate() { if( size_t(idx) >= p->length() ) idx=-1; }
     49     
     50      /// Type of the underlying graph.
     51      typedef typename GR Graph;
     52      /// Edge type of the underlying graph.
     53      typedef typename Graph::Edge GraphEdge;
     54      /// Node type of the underlying graph.
     55      typedef typename Graph::Node GraphNode;
     56      class NodeIt;
     57      class EdgeIt;
     58     
     59      /// \param _G The graph in which the path is.
     60      ///
     61      Path(const Graph &_G) {}
     62     
     63      /// Length of the path.
     64      size_t length() const {}
     65      /// Returns whether the path is empty.
     66      bool empty() const {}
     67     
     68      /// Resets the path to an empty path.
     69      void clear() {}
     70
     71      /// \brief Starting point of the path.
     72      ///
     73      /// Starting point of the path.
     74      /// Returns INVALID if the path is empty.
     75      NodeIt head() const {}
     76      /// \brief End point of the path.
     77      ///
     78      /// End point of the path.
     79      /// Returns INVALID if the path is empty.
     80      NodeIt tail() const {}
     81
     82      /// \brief First NodeIt/EdgeIt.
     83      ///
     84      /// Initializes node or edge iterator to point to the first
     85      /// node or edge.
     86      template<typename It>
     87      It& first(It &i) const { return i=It(*this); }
     88
     89      /// \brief The head of an edge.
     90      ///
     91      /// Returns node iterator pointing to the head node of the
     92      /// given edge iterator.
     93      NodeIt head(const EdgeIt& e) const {}
     94
     95      /// \brief The tail of an edge.
     96      ///
     97      /// Returns node iterator pointing to the tail node of the
     98      /// given edge iterator.
     99      NodeIt tail(const EdgeIt& e) const {}
     100
     101
     102      /* Iterator classes */
     103
     104      /**
     105       * \brief Iterator class to iterate on the edges of the paths
     106       *
     107       * \ingroup skeletons
     108       * This class is used to iterate on the edges of the paths
     109       *
     110       * Of course it converts to Graph::Edge
     111       *
     112       */
     113      class EdgeIt {
     114      public:
     115        /// Default constructor
     116        EdgeIt() {}
     117        /// Invalid constructor
     118        EdgeIt(Invalid) {}
     119        /// Constructor with starting point
     120        EdgeIt(const Path &_p) {}
     121
     122        operator GraphEdge () const {}
     123
     124        /// Next edge
     125        EdgeIt& operator++() {}
     126
     127        /// Comparison operator
     128        bool operator==(const EdgeIt& e) const {}
     129        /// Comparison operator
     130        bool operator!=(const EdgeIt& e) const {}
     131//      /// Comparison operator
     132//      /// \todo It is not clear what is the "natural" ordering.
     133//      bool operator<(const EdgeIt& e) const {}
     134
     135      };
     136
     137      /**
     138       * \brief Iterator class to iterate on the nodes of the paths
     139       *
     140       * \ingroup skeletons
     141       * This class is used to iterate on the nodes of the paths
     142       *
     143       * Of course it converts to Graph::Node.
     144       *
     145       */
     146      class NodeIt {
     147      public:
     148        /// Default constructor
     149        NodeIt() {}
     150        /// Invalid constructor
     151        NodeIt(Invalid) {}
     152        /// Constructor with starting point
     153        NodeIt(const Path &_p) {}
     154
     155        ///Conversion to Graph::Node
     156        operator const GraphNode& () const {}
     157        /// Next node
     158        NodeIt& operator++() {}
     159
     160        /// Comparison operator
     161        bool operator==(const NodeIt& e) const {}
     162        /// Comparison operator
     163        bool operator!=(const NodeIt& e) const {}
     164//      /// Comparison operator
     165//      /// \todo It is not clear what is the "natural" ordering.
     166//      bool operator<(const NodeIt& e) const {}
     167
     168      };
     169
     170      friend class Builder;   
     171
     172      /**
     173       * \brief Class to build paths
     174       *
     175       * \ingroup skeletons
     176       * This class is used to fill a path with edges.
     177       *
     178       * You can push new edges to the front and to the back of the path in
     179       * arbitrary order then you should commit these changes to the graph.
     180       *
     181       * While the builder is active (after the first modifying
     182       * operation and until the call of \ref commit())
     183       * the underlining Path is in a
     184       * "transitional" state (operations on it have undefined result).
     185       */
     186      class Builder {
     187      public:
     188        ///\param _P the path you want to fill in.
     189        ///
     190        Builder(Path &_P) : P(_P) {}
     191
     192        /// Sets the starting node of the path.
     193     
     194        /// Sets the starting node of the path. Edge added to the path
     195        /// afterwards have to be incident to this node.
     196        /// You \em must start building an empry path with this functions.
     197        /// (And you \em must \em not use it later).
     198        /// \sa pushFront()
     199        /// \sa pushBack()
     200        void setStartNode(const GraphNode &) {}
     201
     202        ///Push a new edge to the front of the path
     203
     204        ///Push a new edge to the front of the path.
     205        ///If the path is empty, you \em must call \ref setStartNode() before
     206        ///the first use of \ref pushFront().
     207        void pushFront(const GraphEdge& e) {}
     208
     209        ///Push a new edge to the back of the path
     210
     211        ///Push a new edge to the back of the path.
     212        ///If the path is empty, you \em must call \ref setStartNode() before
     213        ///the first use of \ref pushBack().
     214        void pushBack(const GraphEdge& e) {}
     215
     216        ///Commit the changes to the path.
     217        void commit() {}
     218
     219        ///Reserve (front) storage for the builder in advance.
     220
     221        ///If you know an reasonable upper bound of the number of the edges
     222        ///to add to the front of the path,
     223        ///using this function you may speed up the building.
     224        void reserveFront(size_t r) {}
     225        ///Reserve (back) storage for the builder in advance.
     226
     227        ///If you know an reasonable upper bound of the number of the edges
     228        ///to add to the back of the path,
     229        ///using this function you may speed up the building.
     230        void reserveBack(size_t r) {}
     231      };
    220232    };
    221233
    222     /**
    223      * \brief Iterator class to iterate on the nodes of the paths
    224      *
    225      * \ingroup paths
    226      * This class is used to iterate on the nodes of the paths
    227      *
    228      * Of course it converts to Graph::Node
    229      *
    230      * \todo Its interface differs from the standard node iterator.
    231      * Yes, it shouldn't.
    232      */
    233     class NodeIt {
    234       friend class DirPath;
    235 
    236       int idx;
    237       const DirPath *p;
    238     public:
    239       /// Default constructor
    240       NodeIt() {}
    241       /// Invalid constructor
    242       NodeIt(Invalid) : idx(-1), p(0) {}
    243       /// Constructor with starting point
    244       NodeIt(const DirPath &_p, int _idx = 0) :
    245         idx(_idx), p(&_p) { validate(); }
    246 
    247       ///Validity check
    248       bool valid() const { return idx!=-1; }
    249 
    250       ///Conversion to Graph::Node
    251       operator const GraphNode& () const {
    252         if(idx >= p->length())
    253           return p->to();
    254         else if(idx >= 0)
    255           return p->gr->tail(p->edges[idx]);
    256         else
    257           return INVALID;
    258       }
    259       /// Next node
    260       NodeIt& operator++() { ++idx; validate(); return *this; }
    261 
    262       /// Comparison operator
    263       bool operator==(const NodeIt& e) const { return idx==e.idx; }
    264       /// Comparison operator
    265       bool operator!=(const NodeIt& e) const { return idx!=e.idx; }
    266       /// Comparison operator
    267       bool operator<(const NodeIt& e) const { return idx<e.idx; }
    268 
    269     private:
    270       void validate() { if( size_t(idx) > p->length() ) idx=-1; }
    271     };
    272 
    273     friend class Builder;   
    274 
    275     /**
    276      * \brief Class to build paths
    277      *
    278      * \ingroup paths
    279      * This class is used to fill a path with edges.
    280      *
    281      * You can push new edges to the front and to the back of the path in
    282      * arbitrary order then you should commit these changes to the graph.
    283      *
    284      * Fundamentally, for most "Paths" (classes fulfilling the
    285      * PathConcept) while the builder is active (after the first modifying
    286      * operation and until the commit()) the original Path is in a
    287      * "transitional" state (operations on it have undefined result). But
    288      * in the case of DirPath the original path remains unchanged until the
    289      * commit. However we don't recomend that you use this feature.
    290      */
    291     class Builder {
    292       DirPath &P;
    293       Container front, back;
    294 
    295     public:
    296       ///\param _P the path you want to fill in.
    297       ///
    298       Builder(DirPath &_P) : P(_P) {}
    299 
    300       /// Sets the starting node of the path.
    301      
    302       /// Sets the starting node of the path. Edge added to the path
    303       /// afterwards have to be incident to this node.
    304       /// It should be called iff the path is empty and before any call to
    305       /// \ref pushFront() or \ref pushBack()
    306       void setStart(const GraphNode &) {}
    307 
    308       ///Push a new edge to the front of the path
    309 
    310       ///Push a new edge to the front of the path.
    311       ///\sa setStart
    312       void pushFront(const GraphEdge& e) {
    313         if( DM::consistensy_check && !empty() && P.gr->head(e)!=from() ) {
    314           fault("DirPath::Builder::pushFront: nonincident edge");
    315         }
    316         front.push_back(e);
    317       }
    318 
    319       ///Push a new edge to the back of the path
    320 
    321       ///Push a new edge to the back of the path.
    322       ///\sa setStart
    323       void pushBack(const GraphEdge& e) {
    324         if( DM::consistensy_check && !empty() && P.gr->tail(e)!=to() ) {
    325           fault("DirPath::Builder::pushBack: nonincident edge");
    326         }
    327         back.push_back(e);
    328       }
    329 
    330       ///Commit the changes to the path.
    331       void commit() {
    332         if( !(front.empty() && back.empty()) ) {
    333           Container tmp;
    334           tmp.reserve(front.size()+back.size()+P.length());
    335           tmp.insert(tmp.end(), front.rbegin(), front.rend());
    336           tmp.insert(tmp.end(), P.edges.begin(), P.edges.end());
    337           tmp.insert(tmp.end(), back.begin(), back.end());
    338           P.edges.swap(tmp);
    339           front.clear();
    340           back.clear();
    341         }
    342       }
    343 
    344       // FIXME: Hmm, pontosan hogy is kene ezt csinalni?
    345       // Hogy kenyelmes egy ilyet hasznalni?
    346  
    347       ///Reserve storage in advance for the builder
    348 
    349       ///If you know an reasonable upper bound of the number of the edges
    350       ///to add, using this function you can speed up the building.
    351       void reserve(size_t r) {
    352         front.reserve(r);
    353         back.reserve(r);
    354       }
    355 
    356     private:
    357       bool empty() {
    358         return front.empty() && back.empty() && P.empty();
    359       }
    360 
    361       GraphNode from() const {
    362         if( ! front.empty() )
    363           return P.gr->tail(front[front.size()-1]);
    364         else if( ! P.empty() )
    365           return P.gr->tail(P.edges[0]);
    366         else if( ! back.empty() )
    367           return P.gr->tail(back[0]);
    368         else
    369           return INVALID;
    370       }
    371       GraphNode to() const {
    372         if( ! back.empty() )
    373           return P.gr->head(back[back.size()-1]);
    374         else if( ! P.empty() )
    375           return P.gr->head(P.edges[P.length()-1]);
    376         else if( ! front.empty() )
    377           return P.gr->head(front[0]);
    378         else
    379           return INVALID;
    380       }
    381 
    382     };
    383 
    384   };
    385 
    386 
    387 
    388 
    389 
    390 
    391 
    392 
    393 
    394 
    395   /**********************************************************************/
    396 
    397 
    398   //! \brief A structure for representing undirected path in a graph.
    399   //!
    400   //! A structure for representing undirected path in a graph. Ie. this is
    401   //! a path in a \e directed graph but the edges should not be directed
    402   //! forward.
    403   //!
    404   //! \param Graph The graph type in which the path is.
    405   //! \param DM DebugMode, defaults to DefaultDebugMode.
    406   //!
    407   //! In a sense, the path can be treated as a graph, for is has \c NodeIt
    408   //! and \c EdgeIt with the same usage. These types converts to the \c Node
    409   //! and \c Edge of the original graph.
    410   //!
    411   //! \todo Thoroughfully check all the range and consistency tests.
    412   template<typename Graph, typename DM = DefaultDebugMode>
    413   class UndirPath {
    414   public:
    415     /// Edge type of the underlying graph.
    416     typedef typename Graph::Edge GraphEdge;
    417      /// Node type of the underlying graph.
    418    typedef typename Graph::Node GraphNode;
    419     class NodeIt;
    420     class EdgeIt;
    421 
    422   protected:
    423     const Graph *gr;
    424     typedef std::vector<GraphEdge> Container;
    425     Container edges;
    426 
    427   public:
    428 
    429     /// \param _G The graph in which the path is.
    430     ///
    431     UndirPath(const Graph &_G) : gr(&_G) {}
    432 
    433     /// \brief Subpath constructor.
    434     ///
    435     /// Subpath defined by two nodes.
    436     /// \warning It is an error if the two edges are not in order!
    437     UndirPath(const UndirPath &P, const NodeIt &a, const NodeIt &b) {
    438       if( DM::range_check && (!a.valid() || !b.valid) ) {
    439         // FIXME: this check should be more elaborate...
    440         fault("UndirPath, subpath ctor: invalid bounding nodes");
    441       }
    442       gr = P.gr;
    443       edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx);
    444     }
    445 
    446     /// \brief Subpath constructor.
    447     ///
    448     /// Subpath defined by two edges. Contains edges in [a,b)
    449     /// \warning It is an error if the two edges are not in order!
    450     UndirPath(const UndirPath &P, const EdgeIt &a, const EdgeIt &b) {
    451       if( DM::range_check && (!a.valid() || !b.valid) ) {
    452         // FIXME: this check should be more elaborate...
    453         fault("UndirPath, subpath ctor: invalid bounding nodes");
    454       }
    455       gr = P.gr;
    456       edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx);
    457     }
    458 
    459     /// Length of the path.
    460     size_t length() const { return edges.size(); }
    461     /// Returns whether the path is empty.
    462     bool empty() const { return edges.empty(); }
    463 
    464     /// Resets the path to an empty path.
    465     void clear() { edges.clear(); }
    466 
    467     /// \brief Starting point of the path.
    468     ///
    469     /// Starting point of the path.
    470     /// Returns INVALID if the path is empty.
    471     GraphNode from() const {
    472       return empty() ? INVALID : gr->tail(edges[0]);
    473     }
    474     /// \brief End point of the path.
    475     ///
    476     /// End point of the path.
    477     /// Returns INVALID if the path is empty.
    478     GraphNode to() const {
    479       return empty() ? INVALID : gr->head(edges[length()-1]);
    480     }
    481 
    482     /// \brief Initializes node or edge iterator to point to the first
    483     /// node or edge.
    484     ///
    485     /// \sa nth
    486     template<typename It>
    487     It& first(It &i) const { return i=It(*this); }
    488 
    489     /// \brief Initializes node iterator to point to the node of a given index.
    490     NodeIt& nth(NodeIt &i, int n) const {
    491       if( DM::range_check && (n<0 || n>int(length())) )
    492         fault("UndirPath::nth: index out of range");
    493       return i=NodeIt(*this, n);
    494     }
    495 
    496     /// \brief Initializes edge iterator to point to the edge of a given index.
    497     EdgeIt& nth(EdgeIt &i, int n) const {
    498       if( DM::range_check && (n<0 || n>=int(length())) )
    499         fault("UndirPath::nth: index out of range");
    500       return i=EdgeIt(*this, n);
    501     }
    502 
    503     /// Checks validity of a node or edge iterator.
    504     template<typename It>
    505     static
    506     bool valid(const It &i) { return i.valid(); }
    507 
    508     /// Steps the given node or edge iterator.
    509     template<typename It>
    510     static
    511     It& next(It &e) {
    512       if( DM::range_check && !e.valid() )
    513         fault("UndirPath::next() on invalid iterator");
    514       return ++e;
    515     }
    516 
    517     /// \brief Returns node iterator pointing to the head node of the
    518     /// given edge iterator.
    519     NodeIt head(const EdgeIt& e) const {
    520       if( DM::range_check && !e.valid() )
    521         fault("UndirPath::head() on invalid iterator");
    522       return NodeIt(*this, e.idx+1);
    523     }
    524 
    525     /// \brief Returns node iterator pointing to the tail node of the
    526     /// given edge iterator.
    527     NodeIt tail(const EdgeIt& e) const {
    528       if( DM::range_check && !e.valid() )
    529         fault("UndirPath::tail() on invalid iterator");
    530       return NodeIt(*this, e.idx);
    531     }
    532 
    533 
    534 
    535     /**
    536      * \brief Iterator class to iterate on the edges of the paths
    537      *
    538      * \ingroup paths
    539      * This class is used to iterate on the edges of the paths
    540      *
    541      * Of course it converts to Graph::Edge
    542      *
    543      * \todo Its interface differs from the standard edge iterator.
    544      * Yes, it shouldn't.
    545      */
    546     class EdgeIt {
    547       friend class UndirPath;
    548 
    549       int idx;
    550       const UndirPath *p;
    551     public:
    552       /// Default constructor
    553       EdgeIt() {}
    554       /// Invalid constructor
    555       EdgeIt(Invalid) : idx(-1), p(0) {}
    556       /// Constructor with starting point
    557       EdgeIt(const UndirPath &_p, int _idx = 0) :
    558         idx(_idx), p(&_p) { validate(); }
    559 
    560       ///Validity check
    561       bool valid() const { return idx!=-1; }
    562 
    563       ///Conversion to Graph::Edge
    564       operator GraphEdge () const {
    565         return valid() ? p->edges[idx] : INVALID;
    566       }
    567       /// Next edge
    568      EdgeIt& operator++() { ++idx; validate(); return *this; }
    569 
    570       /// Comparison operator
    571       bool operator==(const EdgeIt& e) const { return idx==e.idx; }
    572       /// Comparison operator
    573       bool operator!=(const EdgeIt& e) const { return idx!=e.idx; }
    574       /// Comparison operator
    575       bool operator<(const EdgeIt& e) const { return idx<e.idx; }
    576 
    577     private:
    578       // FIXME: comparison between signed and unsigned...
    579       // Jo ez igy? Vagy esetleg legyen a length() int?
    580       void validate() { if( size_t(idx) >= p->length() ) idx=-1; }
    581     };
    582 
    583     /**
    584      * \brief Iterator class to iterate on the nodes of the paths
    585      *
    586      * \ingroup paths
    587      * This class is used to iterate on the nodes of the paths
    588      *
    589      * Of course it converts to Graph::Node
    590      *
    591      * \todo Its interface differs from the standard node iterator.
    592      * Yes, it shouldn't.
    593      */
    594     class NodeIt {
    595       friend class UndirPath;
    596 
    597       int idx;
    598       const UndirPath *p;
    599     public:
    600       /// Default constructor
    601       NodeIt() {}
    602       /// Invalid constructor
    603       NodeIt(Invalid) : idx(-1), p(0) {}
    604       /// Constructor with starting point
    605       NodeIt(const UndirPath &_p, int _idx = 0) :
    606         idx(_idx), p(&_p) { validate(); }
    607 
    608       ///Validity check
    609       bool valid() const { return idx!=-1; }
    610 
    611       ///Conversion to Graph::Node
    612       operator const GraphNode& () const {
    613         if(idx >= p->length())
    614           return p->to();
    615         else if(idx >= 0)
    616           return p->gr->tail(p->edges[idx]);
    617         else
    618           return INVALID;
    619       }
    620       /// Next node
    621       NodeIt& operator++() { ++idx; validate(); return *this; }
    622 
    623       /// Comparison operator
    624       bool operator==(const NodeIt& e) const { return idx==e.idx; }
    625       /// Comparison operator
    626       bool operator!=(const NodeIt& e) const { return idx!=e.idx; }
    627        /// Comparison operator
    628      bool operator<(const NodeIt& e) const { return idx<e.idx; }
    629 
    630     private:
    631       void validate() { if( size_t(idx) > p->length() ) idx=-1; }
    632     };
    633 
    634     friend class Builder;   
    635 
    636     /**
    637      * \brief Class to build paths
    638      *
    639      * \ingroup paths
    640      * This class is used to fill a path with edges.
    641      *
    642      * You can push new edges to the front and to the back of the path in
    643      * arbitrary order then you should commit these changes to the graph.
    644      *
    645      * Fundamentally, for most "Paths" (classes fulfilling the
    646      * PathConcept) while the builder is active (after the first modifying
    647      * operation and until the commit()) the original Path is in a
    648      * "transitional" state (operations ot it have undefined result). But
    649      * in the case of UndirPath the original path is unchanged until the
    650      * commit. However we don't recomend that you use this feature.
    651      */
    652     class Builder {
    653       UndirPath &P;
    654       Container front, back;
    655 
    656     public:
    657       ///\param _P the path you want to fill in.
    658       ///
    659       Builder(UndirPath &_P) : P(_P) {}
    660 
    661       /// Sets the starting node of the path.
    662      
    663       /// Sets the starting node of the path. Edge added to the path
    664       /// afterwards have to be incident to this node.
    665       /// It should be called iff the path is empty and before any call to
    666       /// \ref pushFront() or \ref pushBack()
    667       void setStart(const GraphNode &) {}
    668 
    669       ///Push a new edge to the front of the path
    670 
    671       ///Push a new edge to the front of the path.
    672       ///\sa setStart
    673       void pushFront(const GraphEdge& e) {
    674         if( DM::consistensy_check && !empty() && P.gr->head(e)!=from() ) {
    675           fault("UndirPath::Builder::pushFront: nonincident edge");
    676         }
    677         front.push_back(e);
    678       }
    679 
    680       ///Push a new edge to the back of the path
    681 
    682       ///Push a new edge to the back of the path.
    683       ///\sa setStart
    684       void pushBack(const GraphEdge& e) {
    685         if( DM::consistensy_check && !empty() && P.gr->tail(e)!=to() ) {
    686           fault("UndirPath::Builder::pushBack: nonincident edge");
    687         }
    688         back.push_back(e);
    689       }
    690 
    691       ///Commit the changes to the path.
    692       void commit() {
    693         if( !(front.empty() && back.empty()) ) {
    694           Container tmp;
    695           tmp.reserve(front.size()+back.size()+P.length());
    696           tmp.insert(tmp.end(), front.rbegin(), front.rend());
    697           tmp.insert(tmp.end(), P.edges.begin(), P.edges.end());
    698           tmp.insert(tmp.end(), back.begin(), back.end());
    699           P.edges.swap(tmp);
    700           front.clear();
    701           back.clear();
    702         }
    703       }
    704 
    705       // FIXME: Hmm, pontosan hogy is kene ezt csinalni?
    706       // Hogy kenyelmes egy ilyet hasznalni?
    707 
    708       ///Reserve storage in advance for the builder
    709 
    710       ///If you know an reasonable upper bound of the number of the edges
    711       ///to add, using this function you can speed up the building.
    712        void reserve(size_t r) {
    713         front.reserve(r);
    714         back.reserve(r);
    715       }
    716 
    717     private:
    718       bool empty() {
    719         return front.empty() && back.empty() && P.empty();
    720       }
    721 
    722       GraphNode from() const {
    723         if( ! front.empty() )
    724           return P.gr->tail(front[front.size()-1]);
    725         else if( ! P.empty() )
    726           return P.gr->tail(P.edges[0]);
    727         else if( ! back.empty() )
    728           return P.gr->tail(back[0]);
    729         else
    730           return INVALID;
    731       }
    732       GraphNode to() const {
    733         if( ! back.empty() )
    734           return P.gr->head(back[back.size()-1]);
    735         else if( ! P.empty() )
    736           return P.gr->head(P.edges[P.length()-1]);
    737         else if( ! front.empty() )
    738           return P.gr->head(front[0]);
    739         else
    740           return INVALID;
    741       }
    742 
    743     };
    744 
    745   };
    746 
    747 
    748 
    749 
    750 
    751 
    752 
    753 
    754 
    755 
    756   /**********************************************************************/
    757 
    758 
    759   /* Ennek az allocatorosdinak sokkal jobban utana kene nezni a hasznalata
    760      elott. Eleg bonyinak nez ki, ahogyan azokat az STL-ben hasznaljak. */
    761 
    762   template<typename Graph>
    763   class DynamicPath {
    764 
    765   public:
    766     typedef typename Graph::Edge GraphEdge;
    767     typedef typename Graph::Node GraphNode;
    768     class NodeIt;
    769     class EdgeIt;
    770 
    771   protected:
    772     Graph& G;
    773     // FIXME: ehelyett eleg lenne tarolni ket boolt: a ket szelso el
    774     // iranyitasat:
    775     GraphNode _first, _last;
    776     typedef std::deque<GraphEdge> Container;
    777     Container edges;
    778 
    779   public:
    780 
    781     DynamicPath(Graph &_G) : G(_G), _first(INVALID), _last(INVALID) {}
    782 
    783     /// Subpath defined by two nodes.
    784     /// Nodes may be in reversed order, then
    785     /// we contstruct the reversed path.
    786     DynamicPath(const DynamicPath &P, const NodeIt &a, const NodeIt &b);
    787     /// Subpath defined by two edges. Contains edges in [a,b)
    788     /// It is an error if the two edges are not in order!
    789     DynamicPath(const DynamicPath &P, const EdgeIt &a, const EdgeIt &b);
    790    
    791     size_t length() const { return edges.size(); }
    792     GraphNode from() const { return _first; }
    793     GraphNode to() const { return _last; }
    794 
    795     NodeIt& first(NodeIt &n) const { return nth(n, 0); }
    796     EdgeIt& first(EdgeIt &e) const { return nth(e, 0); }
    797     template<typename It>
    798     It first() const {
    799       It e;
    800       first(e);
    801       return e;
    802     }
    803 
    804     NodeIt& nth(NodeIt &, size_t) const;
    805     EdgeIt& nth(EdgeIt &, size_t) const;
    806     template<typename It>
    807     It nth(size_t n) const {
    808       It e;
    809       nth(e, n);
    810       return e;
    811     }
    812 
    813     bool valid(const NodeIt &n) const { return n.idx <= length(); }
    814     bool valid(const EdgeIt &e) const { return e.it < edges.end(); }
    815 
    816     bool isForward(const EdgeIt &e) const { return e.forw; }
    817 
    818     /// index of a node on the path. Returns length+2 for the invalid NodeIt
    819     int index(const NodeIt &n) const { return n.idx; }
    820     /// index of an edge on the path. Returns length+1 for the invalid EdgeIt
    821     int index(const EdgeIt &e) const { return e.it - edges.begin(); }
    822 
    823     EdgeIt& next(EdgeIt &e) const;
    824     NodeIt& next(NodeIt &n) const;
    825     template <typename It>
    826     It getNext(It it) const {
    827       It tmp(it); return next(tmp);
    828     }
    829 
    830     // A path is constructed using the following four functions.
    831     // They return false if the requested operation is inconsistent
    832     // with the path constructed so far.
    833     // If your path has only one edge you MUST set either "from" or "to"!
    834     // So you probably SHOULD call it in any case to be safe (and check the
    835     // returned value to check if your path is consistent with your idea).
    836     bool pushFront(const GraphEdge &e);
    837     bool pushBack(const GraphEdge &e);
    838     bool setFrom(const GraphNode &n);
    839     bool setTo(const GraphNode &n);
    840 
    841     // WARNING: these two functions return the head/tail of an edge with
    842     // respect to the direction of the path!
    843     // So G.head(P.graphEdge(e)) == P.graphNode(P.head(e)) holds only if
    844     // P.forward(e) is true (or the edge is a loop)!
    845     NodeIt head(const EdgeIt& e) const;
    846     NodeIt tail(const EdgeIt& e) const;
    847 
    848     // FIXME: ezeknek valami jobb nev kellene!!!
    849     GraphEdge graphEdge(const EdgeIt& e) const;
    850     GraphNode graphNode(const NodeIt& n) const;
    851 
    852 
    853     /*** Iterator classes ***/
    854     class EdgeIt {
    855       friend class DynamicPath;
    856 
    857       typename Container::const_iterator it;
    858       bool forw;
    859     public:
    860       // FIXME: jarna neki ilyen is...
    861       // EdgeIt(Invalid);
    862 
    863       bool forward() const { return forw; }
    864 
    865       bool operator==(const EdgeIt& e) const { return it==e.it; }
    866       bool operator!=(const EdgeIt& e) const { return it!=e.it; }
    867       bool operator<(const EdgeIt& e) const { return it<e.it; }
    868     };
    869 
    870     class NodeIt {
    871       friend class DynamicPath;
    872 
    873       size_t idx;
    874       bool tail;  // Is this node the tail of the edge with same idx?
    875 
    876     public:
    877       // FIXME: jarna neki ilyen is...
    878       // NodeIt(Invalid);
    879 
    880       bool operator==(const NodeIt& n) const { return idx==n.idx; }
    881       bool operator!=(const NodeIt& n) const { return idx!=n.idx; }
    882       bool operator<(const NodeIt& n) const { return idx<n.idx; }
    883     };
    884 
    885   private:
    886     bool edgeIncident(const GraphEdge &e, const GraphNode &a,
    887                       GraphNode &b);
    888     bool connectTwoEdges(const GraphEdge &e, const GraphEdge &f);
    889   };
    890 
    891   template<typename Gr>
    892   typename DynamicPath<Gr>::EdgeIt&
    893   DynamicPath<Gr>::next(DynamicPath::EdgeIt &e) const {
    894     if( e.it == edges.end() )
    895       return e;
    896 
    897     GraphNode common_node = ( e.forw ? G.head(*e.it) : G.tail(*e.it) );
    898     ++e.it;
    899 
    900     // Invalid edgeit is always forward :)
    901     if( e.it == edges.end() ) {
    902       e.forw = true;
    903       return e;
    904     }
    905 
    906     e.forw = ( G.tail(*e.it) == common_node );
    907     return e;
    908   }
    909 
    910   template<typename Gr>
    911   typename DynamicPath<Gr>::NodeIt& DynamicPath<Gr>::next(NodeIt &n) const {
    912     if( n.idx >= length() ) {
    913       // FIXME: invalid
    914       n.idx = length()+1;
    915       return n;
    916     }
    917 
    918    
    919     GraphNode next_node = ( n.tail ? G.head(edges[n.idx]) :
    920                               G.tail(edges[n.idx]) );
    921     ++n.idx;
    922     if( n.idx < length() ) {
    923       n.tail = ( next_node == G.tail(edges[n.idx]) );
    924     }
    925     else {
    926       n.tail = true;
    927     }
    928 
    929     return n;
    930   }
    931 
    932   template<typename Gr>
    933   bool DynamicPath<Gr>::edgeIncident(const GraphEdge &e, const GraphNode &a,
    934                           GraphNode &b) {
    935     if( G.tail(e) == a ) {
    936       b=G.head(e);
    937       return true;
    938     }
    939     if( G.head(e) == a ) {
    940       b=G.tail(e);
    941       return true;
    942     }
    943     return false;
    944   }
    945 
    946   template<typename Gr>
    947   bool DynamicPath<Gr>::connectTwoEdges(const GraphEdge &e,
    948                              const GraphEdge &f) {
    949     if( edgeIncident(f, G.tail(e), _last) ) {
    950       _first = G.head(e);
    951       return true;
    952     }
    953     if( edgeIncident(f, G.head(e), _last) ) {
    954       _first = G.tail(e);
    955       return true;
    956     }
    957     return false;
    958   }
    959 
    960   template<typename Gr>
    961   bool DynamicPath<Gr>::pushFront(const GraphEdge &e) {
    962     if( G.valid(_first) ) {
    963         if( edgeIncident(e, _first, _first) ) {
    964           edges.push_front(e);
    965           return true;
    966         }
    967         else
    968           return false;
    969     }
    970     else if( length() < 1 || connectTwoEdges(e, edges[0]) ) {
    971       edges.push_front(e);
    972       return true;
    973     }
    974     else
    975       return false;
    976   }
    977 
    978   template<typename Gr>
    979   bool DynamicPath<Gr>::pushBack(const GraphEdge &e) {
    980     if( G.valid(_last) ) {
    981         if( edgeIncident(e, _last, _last) ) {
    982           edges.push_back(e);
    983           return true;
    984         }
    985         else
    986           return false;
    987     }
    988     else if( length() < 1 || connectTwoEdges(edges[0], e) ) {
    989       edges.push_back(e);
    990       return true;
    991     }
    992     else
    993       return false;
    994   }
    995 
    996 
    997   template<typename Gr>
    998   bool DynamicPath<Gr>::setFrom(const GraphNode &n) {
    999     if( G.valid(_first) ) {
    1000       return _first == n;
    1001     }
    1002     else {
    1003       if( length() > 0) {
    1004         if( edgeIncident(edges[0], n, _last) ) {
    1005           _first = n;
    1006           return true;
    1007         }
    1008         else return false;
    1009       }
    1010       else {
    1011         _first = _last = n;
    1012         return true;
    1013       }
    1014     }
    1015   }
    1016 
    1017   template<typename Gr>
    1018   bool DynamicPath<Gr>::setTo(const GraphNode &n) {
    1019     if( G.valid(_last) ) {
    1020       return _last == n;
    1021     }
    1022     else {
    1023       if( length() > 0) {
    1024         if( edgeIncident(edges[0], n, _first) ) {
    1025           _last = n;
    1026           return true;
    1027         }
    1028         else return false;
    1029       }
    1030       else {
    1031         _first = _last = n;
    1032         return true;
    1033       }
    1034     }
    1035   }
    1036 
    1037 
    1038   template<typename Gr>
    1039   typename DynamicPath<Gr>::NodeIt
    1040   DynamicPath<Gr>::tail(const EdgeIt& e) const {
    1041     NodeIt n;
    1042 
    1043     if( e.it == edges.end() ) {
    1044       // FIXME: invalid-> invalid
    1045       n.idx = length() + 1;
    1046       n.tail = true;
    1047       return n;
    1048     }
    1049 
    1050     n.idx = e.it-edges.begin();
    1051     n.tail = e.forw;
    1052     return n;
    1053   }
    1054 
    1055   template<typename Gr>
    1056   typename DynamicPath<Gr>::NodeIt
    1057   DynamicPath<Gr>::head(const EdgeIt& e) const {
    1058     if( e.it == edges.end()-1 ) {
    1059       return _last;
    1060     }
    1061 
    1062     EdgeIt next_edge = e;
    1063     next(next_edge);
    1064     return tail(next_edge);
    1065   }
    1066      
    1067   template<typename Gr>
    1068   typename DynamicPath<Gr>::GraphEdge
    1069   DynamicPath<Gr>::graphEdge(const EdgeIt& e) const {
    1070     if( e.it != edges.end() ) {
    1071       return *e.it;
    1072     }
    1073     else {
    1074       return INVALID;
    1075     }
     234  ///@}
    1076235  }
    1077236 
    1078   template<typename Gr>
    1079   typename DynamicPath<Gr>::GraphNode
    1080   DynamicPath<Gr>::graphNode(const NodeIt& n) const {
    1081     if( n.idx < length() ) {
    1082       return n.tail ? G.tail(edges[n.idx]) : G.head(edges[n.idx]);
    1083     }
    1084     else if( n.idx == length() ) {
    1085       return _last;
    1086     }
    1087     else {
    1088       return INVALID;
    1089     }
    1090   }
    1091 
    1092   template<typename Gr>
    1093   typename DynamicPath<Gr>::EdgeIt&
    1094   DynamicPath<Gr>::nth(EdgeIt &e, size_t k) const {
    1095     if( k>=length() ) {
    1096       // FIXME: invalid EdgeIt
    1097       e.it = edges.end();
    1098       e.forw = true;
    1099       return e;
    1100     }
    1101 
    1102     e.it = edges.begin()+k;
    1103     if(k==0) {
    1104       e.forw = ( G.tail(*e.it) == _first );
    1105     }
    1106     else {
    1107       e.forw = ( G.tail(*e.it) == G.tail(edges[k-1]) ||
    1108                  G.tail(*e.it) == G.head(edges[k-1]) );
    1109     }
    1110     return e;
    1111   }
    1112    
    1113   template<typename Gr>
    1114   typename DynamicPath<Gr>::NodeIt&
    1115   DynamicPath<Gr>::nth(NodeIt &n, size_t k) const {
    1116     if( k>length() ) {
    1117       // FIXME: invalid NodeIt
    1118       n.idx = length()+1;
    1119       n.tail = true;
    1120       return n;
    1121     }
    1122     if( k==length() ) {
    1123       n.idx = length();
    1124       n.tail = true;
    1125       return n;
    1126     }
    1127     n = tail(nth<EdgeIt>(k));
    1128     return n;
    1129   }
    1130 
    1131   // Reszut konstruktorok:
    1132 
    1133 
    1134   template<typename Gr>
    1135   DynamicPath<Gr>::DynamicPath(const DynamicPath &P, const EdgeIt &a,
    1136                                const EdgeIt &b) :
    1137     G(P.G), edges(a.it, b.it)    // WARNING: if b.it < a.it this will blow up!
    1138   {
    1139     if( G.valid(P._first) && a.it < P.edges.end() ) {
    1140       _first = ( a.forw ? G.tail(*a.it) : G.head(*a.it) );
    1141       if( b.it < P.edges.end() ) {
    1142         _last = ( b.forw ? G.tail(*b.it) : G.head(*b.it) );
    1143       }
    1144       else {
    1145         _last = P._last;
    1146       }
    1147     }
    1148   }
    1149 
    1150   template<typename Gr>
    1151   DynamicPath<Gr>::DynamicPath(const DynamicPath &P, const NodeIt &a,
    1152                                const NodeIt &b) : G(P.G)
    1153   {
    1154     if( !P.valid(a) || !P.valid(b) )
    1155       return;
    1156 
    1157     int ai = a.idx, bi = b.idx;
    1158     if( bi<ai )
    1159       std::swap(ai,bi);
    1160    
    1161     edges.resize(bi-ai);
    1162     copy(P.edges.begin()+ai, P.edges.begin()+bi, edges.begin());
    1163 
    1164     _first = P.graphNode(a);
    1165     _last = P.graphNode(b);
    1166   }
    1167 
    1168   ///@}
    1169 
    1170237} // namespace hugo
    1171238
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