COIN-OR::LEMON - Graph Library

Changeset 286:da414906fe21 in lemon-1.0 for lemon


Ignore:
Timestamp:
09/26/08 12:40:11 (11 years ago)
Author:
Peter Kovacs <kpeter@…>
Branch:
default
Phase:
public
Message:

Improvements related to BFS/DFS/Dijkstra (ticket #96)

  • Add run(s,t) function to BfsVisit?.
  • Modify run(s,t) functions in the class interfaces to return bool value.
  • Bug fix in Dijkstra::start(t) function.
  • Improve Dijkstra::currentDist().
  • Extend test files to check named class template parameters.
  • Doc improvements.
Location:
lemon
Files:
3 edited

Legend:

Unmodified
Added
Removed
  • lemon/bfs.h

    r278 r286  
    608608    ///
    609609    ///This method runs the %BFS algorithm from the root node(s)
    610     ///in order to compute the shortest path to \c dest.
     610    ///in order to compute the shortest path to \c t.
    611611    ///
    612612    ///The algorithm computes
    613     ///- the shortest path to \c dest,
    614     ///- the distance of \c dest from the root(s).
     613    ///- the shortest path to \c t,
     614    ///- the distance of \c t from the root(s).
    615615    ///
    616616    ///\pre init() must be called and at least one root node should be
     
    624624    ///  }
    625625    ///\endcode
    626     void start(Node dest)
     626    void start(Node t)
    627627    {
    628628      bool reach = false;
    629       while ( !emptyQueue() && !reach ) processNextNode(dest, reach);
     629      while ( !emptyQueue() && !reach ) processNextNode(t, reach);
    630630    }
    631631
     
    665665    }
    666666
    667     ///Runs the algorithm from the given node.
     667    ///Runs the algorithm from the given source node.
    668668
    669669    ///This method runs the %BFS algorithm from node \c s
     
    689689
    690690    ///This method runs the %BFS algorithm from node \c s
    691     ///in order to compute the shortest path to \c t.
    692     ///
    693     ///\return The length of the shortest <tt>s</tt>--<tt>t</tt> path,
    694     ///if \c t is reachable form \c s, \c 0 otherwise.
     691    ///in order to compute the shortest path to node \c t
     692    ///(it stops searching when \c t is processed).
     693    ///
     694    ///\return \c true if \c t is reachable form \c s.
    695695    ///
    696696    ///\note Apart from the return value, <tt>b.run(s,t)</tt> is just a
     
    701701    ///  b.start(t);
    702702    ///\endcode
    703     int run(Node s,Node t) {
     703    bool run(Node s,Node t) {
    704704      init();
    705705      addSource(s);
    706706      start(t);
    707       return reached(t) ? _curr_dist : 0;
     707      return reached(t);
    708708    }
    709709
     
    16221622    ///
    16231623    /// This method runs the %BFS algorithm from the root node(s)
    1624     /// in order to compute the shortest path to \c dest.
     1624    /// in order to compute the shortest path to \c t.
    16251625    ///
    16261626    /// The algorithm computes
    1627     /// - the shortest path to \c dest,
    1628     /// - the distance of \c dest from the root(s).
     1627    /// - the shortest path to \c t,
     1628    /// - the distance of \c t from the root(s).
    16291629    ///
    16301630    /// \pre init() must be called and at least one root node should be
     
    16381638    ///   }
    16391639    /// \endcode
    1640     void start(Node dest) {
     1640    void start(Node t) {
    16411641      bool reach = false;
    1642       while ( !emptyQueue() && !reach ) processNextNode(dest, reach);
     1642      while ( !emptyQueue() && !reach ) processNextNode(t, reach);
    16431643    }
    16441644
     
    16781678    }
    16791679
    1680     /// \brief Runs the algorithm from the given node.
     1680    /// \brief Runs the algorithm from the given source node.
    16811681    ///
    16821682    /// This method runs the %BFS algorithm from node \c s
     
    16971697      addSource(s);
    16981698      start();
     1699    }
     1700
     1701    /// \brief Finds the shortest path between \c s and \c t.
     1702    ///
     1703    /// This method runs the %BFS algorithm from node \c s
     1704    /// in order to compute the shortest path to node \c t
     1705    /// (it stops searching when \c t is processed).
     1706    ///
     1707    /// \return \c true if \c t is reachable form \c s.
     1708    ///
     1709    /// \note Apart from the return value, <tt>b.run(s,t)</tt> is just a
     1710    /// shortcut of the following code.
     1711    ///\code
     1712    ///   b.init();
     1713    ///   b.addSource(s);
     1714    ///   b.start(t);
     1715    ///\endcode
     1716    bool run(Node s,Node t) {
     1717      init();
     1718      addSource(s);
     1719      start(t);
     1720      return reached(t);
    16991721    }
    17001722
  • lemon/dfs.h

    r278 r286  
    559559    ///
    560560    ///This method runs the %DFS algorithm from the root node
    561     ///in order to compute the DFS path to \c dest.
     561    ///in order to compute the DFS path to \c t.
    562562    ///
    563563    ///The algorithm computes
    564     ///- the %DFS path to \c dest,
    565     ///- the distance of \c dest from the root in the %DFS tree.
     564    ///- the %DFS path to \c t,
     565    ///- the distance of \c t from the root in the %DFS tree.
    566566    ///
    567567    ///\pre init() must be called and a root node should be
    568568    ///added with addSource() before using this function.
    569     void start(Node dest)
    570     {
    571       while ( !emptyQueue() && G->target(_stack[_stack_head])!=dest )
     569    void start(Node t)
     570    {
     571      while ( !emptyQueue() && G->target(_stack[_stack_head])!=t )
    572572        processNextArc();
    573573    }
     
    599599    }
    600600
    601     ///Runs the algorithm from the given node.
     601    ///Runs the algorithm from the given source node.
    602602
    603603    ///This method runs the %DFS algorithm from node \c s
     
    623623
    624624    ///This method runs the %DFS algorithm from node \c s
    625     ///in order to compute the DFS path to \c t.
    626     ///
    627     ///\return The length of the <tt>s</tt>--<tt>t</tt> DFS path,
    628     ///if \c t is reachable form \c s, \c 0 otherwise.
     625    ///in order to compute the DFS path to node \c t
     626    ///(it stops searching when \c t is processed)
     627    ///
     628    ///\return \c true if \c t is reachable form \c s.
    629629    ///
    630630    ///\note Apart from the return value, <tt>d.run(s,t)</tt> is
     
    635635    ///  d.start(t);
    636636    ///\endcode
    637     int run(Node s,Node t) {
     637    bool run(Node s,Node t) {
    638638      init();
    639639      addSource(s);
    640640      start(t);
    641       return reached(t)?_stack_head+1:0;
     641      return reached(t);
    642642    }
    643643
     
    15271527    ///
    15281528    /// This method runs the %DFS algorithm from the root node
    1529     /// in order to compute the DFS path to \c dest.
     1529    /// in order to compute the DFS path to \c t.
    15301530    ///
    15311531    /// The algorithm computes
    1532     /// - the %DFS path to \c dest,
    1533     /// - the distance of \c dest from the root in the %DFS tree.
     1532    /// - the %DFS path to \c t,
     1533    /// - the distance of \c t from the root in the %DFS tree.
    15341534    ///
    15351535    /// \pre init() must be called and a root node should be added
    15361536    /// with addSource() before using this function.
    1537     void start(Node dest) {
    1538       while ( !emptyQueue() && _digraph->target(_stack[_stack_head]) != dest )
     1537    void start(Node t) {
     1538      while ( !emptyQueue() && _digraph->target(_stack[_stack_head]) != t )
    15391539        processNextArc();
    15401540    }
     
    15651565    }
    15661566
    1567     /// \brief Runs the algorithm from the given node.
     1567    /// \brief Runs the algorithm from the given source node.
    15681568    ///
    15691569    /// This method runs the %DFS algorithm from node \c s.
     
    15891589
    15901590    /// This method runs the %DFS algorithm from node \c s
    1591     /// in order to compute the DFS path to \c t.
    1592     ///
    1593     /// \return The length of the <tt>s</tt>--<tt>t</tt> DFS path,
    1594     /// if \c t is reachable form \c s, \c 0 otherwise.
     1591    /// in order to compute the DFS path to node \c t
     1592    /// (it stops searching when \c t is processed).
     1593    ///
     1594    /// \return \c true if \c t is reachable form \c s.
    15951595    ///
    15961596    /// \note Apart from the return value, <tt>d.run(s,t)</tt> is
     
    16011601    ///   d.start(t);
    16021602    ///\endcode
    1603     int run(Node s,Node t) {
     1603    bool run(Node s,Node t) {
    16041604      init();
    16051605      addSource(s);
    16061606      start(t);
    1607       return reached(t)?_stack_head+1:0;
     1607      return reached(t);
    16081608    }
    16091609
  • lemon/dijkstra.h

    r278 r286  
    729729    }
    730730
    731     ///Executes the algorithm until the given target node is reached.
    732 
    733     ///Executes the algorithm until the given target node is reached.
     731    ///Executes the algorithm until the given target node is processed.
     732
     733    ///Executes the algorithm until the given target node is processed.
    734734    ///
    735735    ///This method runs the %Dijkstra algorithm from the root node(s)
    736     ///in order to compute the shortest path to \c dest.
     736    ///in order to compute the shortest path to \c t.
    737737    ///
    738738    ///The algorithm computes
    739     ///- the shortest path to \c dest,
    740     ///- the distance of \c dest from the root(s).
     739    ///- the shortest path to \c t,
     740    ///- the distance of \c t from the root(s).
    741741    ///
    742742    ///\pre init() must be called and at least one root node should be
    743743    ///added with addSource() before using this function.
    744     void start(Node dest)
    745     {
    746       while ( !_heap->empty() && _heap->top()!=dest ) processNextNode();
    747       if ( !_heap->empty() ) finalizeNodeData(_heap->top(),_heap->prio());
     744    void start(Node t)
     745    {
     746      while ( !_heap->empty() && _heap->top()!=t ) processNextNode();
     747      if ( !_heap->empty() ) {
     748        finalizeNodeData(_heap->top(),_heap->prio());
     749        _heap->pop();
     750      }
    748751    }
    749752
     
    773776    }
    774777
    775     ///Runs the algorithm from the given node.
     778    ///Runs the algorithm from the given source node.
    776779
    777780    ///This method runs the %Dijkstra algorithm from node \c s
     
    797800
    798801    ///This method runs the %Dijkstra algorithm from node \c s
    799     ///in order to compute the shortest path to \c t.
    800     ///
    801     ///\return The length of the shortest <tt>s</tt>--<tt>t</tt> path,
    802     ///if \c t is reachable form \c s, \c 0 otherwise.
     802    ///in order to compute the shortest path to node \c t
     803    ///(it stops searching when \c t is processed).
     804    ///
     805    ///\return \c true if \c t is reachable form \c s.
    803806    ///
    804807    ///\note Apart from the return value, <tt>d.run(s,t)</tt> is just a
     
    809812    ///  d.start(t);
    810813    ///\endcode
    811     Value run(Node s,Node t) {
     814    bool run(Node s,Node t) {
    812815      init();
    813816      addSource(s);
    814817      start(t);
    815       return (*_pred)[t]==INVALID?OperationTraits::zero():(*_dist)[t];
     818      return (*_heap_cross_ref)[t] == Heap::POST_HEAP;
    816819    }
    817820
     
    909912    ///Returns \c true if \c v is processed, i.e. the shortest
    910913    ///path to \c v has already found.
    911     ///\pre Either \ref run() or \ref start()
     914    ///\pre Either \ref run() or \ref init()
    912915    ///must be called before using this function.
    913916    bool processed(Node v) const { return (*_heap_cross_ref)[v] ==
     
    918921    ///Returns the current distance of a node from the root(s).
    919922    ///It may be decreased in the following processes.
    920     ///\pre \c v should be reached but not processed.
    921     Value currentDist(Node v) const { return (*_heap)[v]; }
     923    ///\pre Either \ref run() or \ref init()
     924    ///must be called before using this function and
     925    ///node \c v must be reached but not necessarily processed.
     926    Value currentDist(Node v) const {
     927      return processed(v) ? (*_dist)[v] : (*_heap)[v];
     928    }
    922929
    923930    ///@}
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