COIN-OR::LEMON - Graph Library

Changeset 730:9f529abcaebf in lemon for lemon/bucket_heap.h


Ignore:
Timestamp:
06/11/09 23:13:24 (10 years ago)
Author:
Balazs Dezso <deba@…>
Branch:
default
Children:
733:7439dc5fe1b9, 738:9e54e3b27db0, 740:7bda7860e0a8, 743:c9b9da1a90a0, 748:d1a9224f1e30, 756:0747f332c478, 760:4ac30454f1c1, 765:703ebf476a1d, 805:b31e130db13d
Phase:
public
Message:

Unification of names in heaps (#50)

File:
1 edited

Legend:

Unmodified
Added
Removed
  • lemon/bucket_heap.h

    r729 r730  
    3232  namespace _bucket_heap_bits {
    3333
    34     template <bool minimize>
     34    template <bool MIN>
    3535    struct DirectionTraits {
    3636      static bool less(int left, int right) {
     
    6666  /// the priorities are small. It is not intended to use as dijkstra heap.
    6767  ///
    68   /// \param _ItemIntMap A read and writable Item int map, used internally
     68  /// \param IM A read and write Item int map, used internally
    6969  /// to handle the cross references.
    70   /// \param minimize If the given parameter is true then the heap gives back
    71   /// the lowest priority.
    72   template <typename _ItemIntMap, bool minimize = true>
     70  /// \param MIN If the given parameter is false then instead of the
     71  /// minimum value the maximum can be retrivied with the top() and
     72  /// prio() member functions.
     73  template <typename IM, bool MIN = true>
    7374  class BucketHeap {
    7475
    7576  public:
    7677    /// \e
    77     typedef typename _ItemIntMap::Key Item;
     78    typedef typename IM::Key Item;
    7879    /// \e
    7980    typedef int Prio;
     
    8182    typedef std::pair<Item, Prio> Pair;
    8283    /// \e
    83     typedef _ItemIntMap ItemIntMap;
     84    typedef IM ItemIntMap;
    8485
    8586  private:
    8687
    87     typedef _bucket_heap_bits::DirectionTraits<minimize> Direction;
     88    typedef _bucket_heap_bits::DirectionTraits<MIN> Direction;
    8889
    8990  public:
     
    9596    /// heap's point of view, but may be useful to the user.
    9697    ///
    97     /// The ItemIntMap \e should be initialized in such way that it maps
    98     /// PRE_HEAP (-1) to any element to be put in the heap...
     98    /// The item-int map must be initialized in such way that it assigns
     99    /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
    99100    enum State {
    100       IN_HEAP = 0,
    101       PRE_HEAP = -1,
    102       POST_HEAP = -2
     101      IN_HEAP = 0,    ///< = 0.
     102      PRE_HEAP = -1,  ///< = -1.
     103      POST_HEAP = -2  ///< = -2.
    103104    };
    104105
     
    107108    ///
    108109    /// The constructor.
    109     /// \param _index should be given to the constructor, since it is used
     110    /// \param map should be given to the constructor, since it is used
    110111    /// internally to handle the cross references. The value of the map
    111112    /// should be PRE_HEAP (-1) for each element.
    112     explicit BucketHeap(ItemIntMap &_index) : index(_index), minimal(0) {}
     113    explicit BucketHeap(ItemIntMap &map) : _iim(map), _minimum(0) {}
    113114
    114115    /// The number of items stored in the heap.
    115116    ///
    116117    /// \brief Returns the number of items stored in the heap.
    117     int size() const { return data.size(); }
     118    int size() const { return _data.size(); }
    118119
    119120    /// \brief Checks if the heap stores no items.
    120121    ///
    121122    /// Returns \c true if and only if the heap stores no items.
    122     bool empty() const { return data.empty(); }
     123    bool empty() const { return _data.empty(); }
    123124
    124125    /// \brief Make empty this heap.
     
    129130    /// cross reference map for each item to \c PRE_HEAP.
    130131    void clear() {
    131       data.clear(); first.clear(); minimal = 0;
     132      _data.clear(); _first.clear(); _minimum = 0;
    132133    }
    133134
     
    135136
    136137    void relocate_last(int idx) {
    137       if (idx + 1 < int(data.size())) {
    138         data[idx] = data.back();
    139         if (data[idx].prev != -1) {
    140           data[data[idx].prev].next = idx;
     138      if (idx + 1 < int(_data.size())) {
     139        _data[idx] = _data.back();
     140        if (_data[idx].prev != -1) {
     141          _data[_data[idx].prev].next = idx;
    141142        } else {
    142           first[data[idx].value] = idx;
     143          _first[_data[idx].value] = idx;
    143144        }
    144         if (data[idx].next != -1) {
    145           data[data[idx].next].prev = idx;
     145        if (_data[idx].next != -1) {
     146          _data[_data[idx].next].prev = idx;
    146147        }
    147         index[data[idx].item] = idx;
    148       }
    149       data.pop_back();
     148        _iim[_data[idx].item] = idx;
     149      }
     150      _data.pop_back();
    150151    }
    151152
    152153    void unlace(int idx) {
    153       if (data[idx].prev != -1) {
    154         data[data[idx].prev].next = data[idx].next;
     154      if (_data[idx].prev != -1) {
     155        _data[_data[idx].prev].next = _data[idx].next;
    155156      } else {
    156         first[data[idx].value] = data[idx].next;
    157       }
    158       if (data[idx].next != -1) {
    159         data[data[idx].next].prev = data[idx].prev;
     157        _first[_data[idx].value] = _data[idx].next;
     158      }
     159      if (_data[idx].next != -1) {
     160        _data[_data[idx].next].prev = _data[idx].prev;
    160161      }
    161162    }
    162163
    163164    void lace(int idx) {
    164       if (int(first.size()) <= data[idx].value) {
    165         first.resize(data[idx].value + 1, -1);
    166       }
    167       data[idx].next = first[data[idx].value];
    168       if (data[idx].next != -1) {
    169         data[data[idx].next].prev = idx;
    170       }
    171       first[data[idx].value] = idx;
    172       data[idx].prev = -1;
     165      if (int(_first.size()) <= _data[idx].value) {
     166        _first.resize(_data[idx].value + 1, -1);
     167      }
     168      _data[idx].next = _first[_data[idx].value];
     169      if (_data[idx].next != -1) {
     170        _data[_data[idx].next].prev = idx;
     171      }
     172      _first[_data[idx].value] = idx;
     173      _data[idx].prev = -1;
    173174    }
    174175
     
    188189    /// \param p The priority of the item.
    189190    void push(const Item &i, const Prio &p) {
    190       int idx = data.size();
    191       index[i] = idx;
    192       data.push_back(BucketItem(i, p));
     191      int idx = _data.size();
     192      _iim[i] = idx;
     193      _data.push_back(BucketItem(i, p));
    193194      lace(idx);
    194       if (Direction::less(p, minimal)) {
    195         minimal = p;
     195      if (Direction::less(p, _minimum)) {
     196        _minimum = p;
    196197      }
    197198    }
     
    202203    /// \pre The heap must be nonempty.
    203204    Item top() const {
    204       while (first[minimal] == -1) {
    205         Direction::increase(minimal);
    206       }
    207       return data[first[minimal]].item;
     205      while (_first[_minimum] == -1) {
     206        Direction::increase(_minimum);
     207      }
     208      return _data[_first[_minimum]].item;
    208209    }
    209210
     
    213214    /// \pre The heap must be nonempty.
    214215    Prio prio() const {
    215       while (first[minimal] == -1) {
    216         Direction::increase(minimal);
    217       }
    218       return minimal;
     216      while (_first[_minimum] == -1) {
     217        Direction::increase(_minimum);
     218      }
     219      return _minimum;
    219220    }
    220221
     
    224225    /// \pre The heap must be non-empty.
    225226    void pop() {
    226       while (first[minimal] == -1) {
    227         Direction::increase(minimal);
    228       }
    229       int idx = first[minimal];
    230       index[data[idx].item] = -2;
     227      while (_first[_minimum] == -1) {
     228        Direction::increase(_minimum);
     229      }
     230      int idx = _first[_minimum];
     231      _iim[_data[idx].item] = -2;
    231232      unlace(idx);
    232233      relocate_last(idx);
     
    239240    /// \param i The item to erase.
    240241    void erase(const Item &i) {
    241       int idx = index[i];
    242       index[data[idx].item] = -2;
     242      int idx = _iim[i];
     243      _iim[_data[idx].item] = -2;
    243244      unlace(idx);
    244245      relocate_last(idx);
     
    252253    /// \param i The item.
    253254    Prio operator[](const Item &i) const {
    254       int idx = index[i];
    255       return data[idx].value;
     255      int idx = _iim[i];
     256      return _data[idx].value;
    256257    }
    257258
     
    264265    /// \param p The priority.
    265266    void set(const Item &i, const Prio &p) {
    266       int idx = index[i];
     267      int idx = _iim[i];
    267268      if (idx < 0) {
    268269        push(i, p);
    269       } else if (Direction::less(p, data[idx].value)) {
     270      } else if (Direction::less(p, _data[idx].value)) {
    270271        decrease(i, p);
    271272      } else {
     
    282283    /// \param p The priority.
    283284    void decrease(const Item &i, const Prio &p) {
    284       int idx = index[i];
     285      int idx = _iim[i];
    285286      unlace(idx);
    286       data[idx].value = p;
    287       if (Direction::less(p, minimal)) {
    288         minimal = p;
     287      _data[idx].value = p;
     288      if (Direction::less(p, _minimum)) {
     289        _minimum = p;
    289290      }
    290291      lace(idx);
     
    299300    /// \param p The priority.
    300301    void increase(const Item &i, const Prio &p) {
    301       int idx = index[i];
     302      int idx = _iim[i];
    302303      unlace(idx);
    303       data[idx].value = p;
     304      _data[idx].value = p;
    304305      lace(idx);
    305306    }
     
    314315    /// \param i The item.
    315316    State state(const Item &i) const {
    316       int idx = index[i];
     317      int idx = _iim[i];
    317318      if (idx >= 0) idx = 0;
    318319      return State(idx);
     
    333334          erase(i);
    334335        }
    335         index[i] = st;
     336        _iim[i] = st;
    336337        break;
    337338      case IN_HEAP:
     
    352353    };
    353354
    354     ItemIntMap& index;
    355     std::vector<int> first;
    356     std::vector<BucketItem> data;
    357     mutable int minimal;
     355    ItemIntMap& _iim;
     356    std::vector<int> _first;
     357    std::vector<BucketItem> _data;
     358    mutable int _minimum;
    358359
    359360  }; // class BucketHeap
     
    371372  /// minimal and it does not supports key increasing, decreasing.
    372373  ///
    373   /// \param _ItemIntMap A read and writable Item int map, used internally
     374  /// \param IM A read and write Item int map, used internally
    374375  /// to handle the cross references.
    375   /// \param minimize If the given parameter is true then the heap gives back
    376   /// the lowest priority.
     376  /// \param MIN If the given parameter is false then instead of the
     377  /// minimum value the maximum can be retrivied with the top() and
     378  /// prio() member functions.
    377379  ///
    378380  /// \sa BucketHeap
    379   template <typename _ItemIntMap, bool minimize = true >
     381  template <typename IM, bool MIN = true >
    380382  class SimpleBucketHeap {
    381383
    382384  public:
    383     typedef typename _ItemIntMap::Key Item;
     385    typedef typename IM::Key Item;
    384386    typedef int Prio;
    385387    typedef std::pair<Item, Prio> Pair;
    386     typedef _ItemIntMap ItemIntMap;
     388    typedef IM ItemIntMap;
    387389
    388390  private:
    389391
    390     typedef _bucket_heap_bits::DirectionTraits<minimize> Direction;
     392    typedef _bucket_heap_bits::DirectionTraits<MIN> Direction;
    391393
    392394  public:
     
    398400    /// heap's point of view, but may be useful to the user.
    399401    ///
    400     /// The ItemIntMap \e should be initialized in such way that it maps
    401     /// PRE_HEAP (-1) to any element to be put in the heap...
     402    /// The item-int map must be initialized in such way that it assigns
     403    /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
    402404    enum State {
    403       IN_HEAP = 0,
    404       PRE_HEAP = -1,
    405       POST_HEAP = -2
     405      IN_HEAP = 0,    ///< = 0.
     406      PRE_HEAP = -1,  ///< = -1.
     407      POST_HEAP = -2  ///< = -2.
    406408    };
    407409
     
    411413    ///
    412414    /// The constructor.
    413     /// \param _index should be given to the constructor, since it is used
     415    /// \param map should be given to the constructor, since it is used
    414416    /// internally to handle the cross references. The value of the map
    415417    /// should be PRE_HEAP (-1) for each element.
    416     explicit SimpleBucketHeap(ItemIntMap &_index)
    417       : index(_index), free(-1), num(0), minimal(0) {}
     418    explicit SimpleBucketHeap(ItemIntMap &map)
     419      : _iim(map), _free(-1), _num(0), _minimum(0) {}
    418420
    419421    /// \brief Returns the number of items stored in the heap.
    420422    ///
    421423    /// The number of items stored in the heap.
    422     int size() const { return num; }
     424    int size() const { return _num; }
    423425
    424426    /// \brief Checks if the heap stores no items.
    425427    ///
    426428    /// Returns \c true if and only if the heap stores no items.
    427     bool empty() const { return num == 0; }
     429    bool empty() const { return _num == 0; }
    428430
    429431    /// \brief Make empty this heap.
     
    434436    /// cross reference map for each item to \c PRE_HEAP.
    435437    void clear() {
    436       data.clear(); first.clear(); free = -1; num = 0; minimal = 0;
     438      _data.clear(); _first.clear(); _free = -1; _num = 0; _minimum = 0;
    437439    }
    438440
     
    452454    void push(const Item &i, const Prio &p) {
    453455      int idx;
    454       if (free == -1) {
    455         idx = data.size();
    456         data.push_back(BucketItem(i));
     456      if (_free == -1) {
     457        idx = _data.size();
     458        _data.push_back(BucketItem(i));
    457459      } else {
    458         idx = free;
    459         free = data[idx].next;
    460         data[idx].item = i;
    461       }
    462       index[i] = idx;
    463       if (p >= int(first.size())) first.resize(p + 1, -1);
    464       data[idx].next = first[p];
    465       first[p] = idx;
    466       if (Direction::less(p, minimal)) {
    467         minimal = p;
    468       }
    469       ++num;
     460        idx = _free;
     461        _free = _data[idx].next;
     462        _data[idx].item = i;
     463      }
     464      _iim[i] = idx;
     465      if (p >= int(_first.size())) _first.resize(p + 1, -1);
     466      _data[idx].next = _first[p];
     467      _first[p] = idx;
     468      if (Direction::less(p, _minimum)) {
     469        _minimum = p;
     470      }
     471      ++_num;
    470472    }
    471473
     
    475477    /// \pre The heap must be nonempty.
    476478    Item top() const {
    477       while (first[minimal] == -1) {
    478         Direction::increase(minimal);
    479       }
    480       return data[first[minimal]].item;
     479      while (_first[_minimum] == -1) {
     480        Direction::increase(_minimum);
     481      }
     482      return _data[_first[_minimum]].item;
    481483    }
    482484
     
    486488    /// \pre The heap must be nonempty.
    487489    Prio prio() const {
    488       while (first[minimal] == -1) {
    489         Direction::increase(minimal);
    490       }
    491       return minimal;
     490      while (_first[_minimum] == -1) {
     491        Direction::increase(_minimum);
     492      }
     493      return _minimum;
    492494    }
    493495
     
    497499    /// \pre The heap must be non-empty.
    498500    void pop() {
    499       while (first[minimal] == -1) {
    500         Direction::increase(minimal);
    501       }
    502       int idx = first[minimal];
    503       index[data[idx].item] = -2;
    504       first[minimal] = data[idx].next;
    505       data[idx].next = free;
    506       free = idx;
    507       --num;
     501      while (_first[_minimum] == -1) {
     502        Direction::increase(_minimum);
     503      }
     504      int idx = _first[_minimum];
     505      _iim[_data[idx].item] = -2;
     506      _first[_minimum] = _data[idx].next;
     507      _data[idx].next = _free;
     508      _free = idx;
     509      --_num;
    508510    }
    509511
     
    517519    /// \param i The item.
    518520    Prio operator[](const Item &i) const {
    519       for (int k = 0; k < first.size(); ++k) {
    520         int idx = first[k];
     521      for (int k = 0; k < _first.size(); ++k) {
     522        int idx = _first[k];
    521523        while (idx != -1) {
    522           if (data[idx].item == i) {
     524          if (_data[idx].item == i) {
    523525            return k;
    524526          }
    525           idx = data[idx].next;
     527          idx = _data[idx].next;
    526528        }
    527529      }
     
    538540    /// \param i The item.
    539541    State state(const Item &i) const {
    540       int idx = index[i];
     542      int idx = _iim[i];
    541543      if (idx >= 0) idx = 0;
    542544      return State(idx);
     
    553555    };
    554556
    555     ItemIntMap& index;
    556     std::vector<int> first;
    557     std::vector<BucketItem> data;
    558     int free, num;
    559     mutable int minimal;
     557    ItemIntMap& _iim;
     558    std::vector<int> _first;
     559    std::vector<BucketItem> _data;
     560    int _free, _num;
     561    mutable int _minimum;
    560562
    561563  }; // class SimpleBucketHeap
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