lemon/iterable_maps.h
author alpar
Fri, 18 Nov 2005 11:13:11 +0000
changeset 1816 19ee9133a28c
parent 1805 d284f81f02a5
child 1873 d73c7f115f53
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     1 /* -*- C++ -*-
     2  * lemon/iterable_maps.h - Part of LEMON, a generic C++ optimization library
     3  *
     4  * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     5  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     6  *
     7  * Permission to use, modify and distribute this software is granted
     8  * provided that this copyright notice appears in all copies. For
     9  * precise terms see the accompanying LICENSE file.
    10  *
    11  * This software is provided "AS IS" with no warranty of any kind,
    12  * express or implied, and with no claim as to its suitability for any
    13  * purpose.
    14  *
    15  */
    16 
    17 #include <lemon/traits.h>
    18 #include <lemon/invalid.h>
    19 #include <vector>
    20 #include <limits>
    21 
    22 ///\ingroup maps
    23 ///\file
    24 ///\brief Maps that makes it possible to iterate through the keys having
    25 ///a certain value
    26 ///
    27 ///
    28 
    29 
    30 namespace lemon {
    31   
    32   ///\todo This is only a static map!
    33   ///\todo Undocumented.
    34   ///\param BaseMap is an interger map.
    35   template<class BaseMap>
    36   class IterableBoolMap
    37   {
    38   public:
    39   
    40     typedef typename BaseMap::Key Key;
    41     typedef bool Value;
    42   
    43     friend class RefType;
    44     friend class FalseIt;
    45     friend class TrueIt;
    46 
    47   private:
    48     BaseMap &cref;
    49     std::vector<Key> vals;
    50     int sep;           //map[e] is true <=> cref[e]>=sep
    51   
    52     bool isTrue(Key k) {return cref[k]>=sep;}
    53     void swap(Key k, int s) 
    54     {
    55       int ti=cref[k];
    56       Key tk=vals[s];
    57       cref[k]=s; vals[s]=k;
    58       cref[tk]=ti; vals[ti]=tk;
    59     }  
    60 
    61     void setTrue(Key k) { if(cref[k]<sep) { sep--; swap(k,sep); } }
    62     void setFalse(Key k) { if(cref[k]>=sep) { swap(k,sep); sep++; } }
    63   
    64   public:
    65     ///\e
    66     void set(Key k,Value v) { if(v) setTrue(k); else setFalse(k);}
    67     ///Number of \c true items in the map
    68 
    69     ///Returns the number of \c true values in the map.
    70     ///This is a constant time operation.
    71     int countTrue() { return vals.size()-sep; }
    72     ///Number of \c false items in the map
    73 
    74     ///Returns the number of \c false values in the map.
    75     ///This is a constant time operation.
    76     int countFalse() { return sep; }
    77 
    78     ///\e
    79     class FalseIt
    80     {
    81       const IterableBoolMap &M;
    82       int i;
    83     public:
    84       ///\e
    85       explicit FalseIt(const IterableBoolMap &_M) : M(_M), i(0) { }
    86       ///\e
    87       FalseIt(Invalid)
    88 	: M(*((IterableBoolMap*)(0))), i(std::numeric_limits<int>::max()) { }
    89       ///\e
    90       FalseIt &operator++() { ++i; return *this;}
    91       ///\e
    92       operator Key() const { return i<M.sep ? M.vals[i] : INVALID; }
    93       ///\e
    94       bool operator !=(Invalid) const { return i<M.sep; }
    95       ///\e
    96       bool operator ==(Invalid) const { return i>=M.sep; }
    97     };
    98     ///\e
    99     class TrueIt
   100     {
   101       const IterableBoolMap &M;
   102       int i;
   103     public:
   104       ///\e
   105       explicit TrueIt(const IterableBoolMap &_M)
   106 	: M(_M), i(M.vals.size()-1) { }
   107       ///\e
   108       TrueIt(Invalid)
   109 	: M(*((IterableBoolMap*)(0))), i(-1) { }
   110       ///\e
   111       TrueIt &operator++() { --i; return *this;}
   112       ///\e
   113       operator Key() const { return i>=M.sep ? M.vals[i] : INVALID; }
   114       ///\e
   115       bool operator !=(Invalid) const { return i>=M.sep; }
   116       ///\e
   117       bool operator ==(Invalid) const { return i<M.sep; }
   118     };
   119   
   120     ///\e
   121     class RefType
   122     {
   123       IterableBoolMap &M;
   124       Key k;
   125     public:
   126       RefType(IterableBoolMap &_M,Key _k) : M(_M), k(_k) { }
   127     
   128       operator Value() const 
   129       {
   130 	return M.isTrue(k);
   131       }
   132       Value operator = (Value v) const { M.set(k,v); return v; }
   133     };
   134   
   135   public:
   136     explicit IterableBoolMap(BaseMap &_m,bool init=false) : cref(_m)
   137     {
   138       sep=0;
   139       for(typename BaseMap::MapIt i(cref);i!=INVALID; ++i) {
   140 	i.set(sep);
   141 	vals.push_back(i);
   142 	sep++;
   143       }
   144       if(init) sep=0;
   145     }
   146     ///\e
   147     RefType operator[] (Key k) { return RefType(*this,k);}  
   148     ///\e
   149     Value operator[] (Key k) const { return isTrue(k);}  
   150   };
   151 
   152 
   153 
   154 
   155   /// \addtogroup graph_maps
   156   /// @{
   157 
   158   /// Iterable bool NodeMap
   159 
   160   /// This map can be used in the same way
   161   /// as the standard NodeMap<bool> of the
   162   /// given graph \c Graph. 
   163   /// In addition, this class provides two iterators called \ref TrueIt
   164   /// and \ref FalseIt to iterate through the "true" and "false" nodes.
   165   template <class Graph>
   166   class IterableBoolNodeMap
   167   {
   168     typename Graph::template NodeMap<int> cmap;
   169   
   170   public:
   171   
   172     typedef IterableBoolMap<typename Graph::template NodeMap<int> > BimType;
   173     BimType imap;
   174 
   175 
   176     typedef typename BimType::RefType RefType;
   177     typedef typename Graph::Node Key;
   178     typedef bool Value;
   179   
   180     friend class FalseIt;
   181     friend class TrueIt;
   182   
   183     ///\e
   184     IterableBoolNodeMap(const Graph &g,bool b=false) : cmap(g), imap(cmap,b) {}
   185 
   186   public:
   187     ///\e
   188     void set(Key k, bool v) { imap.set(k,v);}
   189     ///Number of \c true items in the map
   190 
   191     ///Returns the number of \c true values in the map.
   192     ///This is a constant time operation.
   193     int countTrue() { return imap.countTrue(); }
   194     ///Number of \c false items in the map
   195 
   196     ///Returns the number of \c false values in the map.
   197     ///This is a constant time operation.
   198     int countFalse() { return imap.countFalse(); }
   199 #ifdef DOXYGEN
   200     ///\e
   201     bool &operator[](Key k) { return imap[k];}  
   202     ///\e
   203     const bool &operator[](Key k) const { return imap[k];}  
   204 #else
   205     Value operator[](Key k) const { return imap[k];}  
   206     RefType operator[](Key k) { return imap[k];}  
   207 #endif
   208     ///Iterator for the "false" nodes
   209     class FalseIt : public BimType::FalseIt
   210     {
   211     public:
   212       ///\e
   213       explicit FalseIt(const IterableBoolNodeMap &m)
   214 	: BimType::FalseIt(m.imap) { }
   215       ///\e
   216       FalseIt(Invalid i) : BimType::FalseIt(i) { }
   217     };
   218     ///Iterator for the "true" nodes
   219     class TrueIt : public BimType::TrueIt
   220     {
   221     public:
   222       ///\e
   223       explicit TrueIt(const IterableBoolNodeMap &m)
   224 	: BimType::TrueIt(m.imap) { }
   225       ///\e
   226       TrueIt(Invalid i) : BimType::TrueIt(i) { }
   227     };  
   228   };
   229 
   230   /// Iterable bool EdgeMap
   231 
   232   /// This map can be used in the same way
   233   /// as the standard EdgeMap<bool> of the
   234   /// given graph \c Graph. 
   235   /// In addition, this class provides two iterators called \ref TrueIt
   236   /// and \ref FalseIt to iterate through the "true" and "false" edges.
   237   template <class Graph>
   238   class IterableBoolEdgeMap
   239   {
   240     typename Graph::template EdgeMap<int> cmap;
   241   
   242   public:
   243   
   244     typedef IterableBoolMap<typename Graph::template EdgeMap<int> > BimType;
   245     BimType imap;
   246 
   247 
   248     typedef typename BimType::RefType RefType;
   249     typedef typename Graph::Edge Key;
   250     typedef bool Value;
   251   
   252     friend class FalseIt;
   253     friend class TrueIt;
   254   
   255     ///\e
   256     IterableBoolEdgeMap(const Graph &g,bool b=false) : cmap(g), imap(cmap,b) {}
   257 
   258   public:
   259     ///\e
   260     void set(Key k, bool v) { imap.set(k,v);}
   261     ///Returns the number of \c true values in the map.
   262     ///This is a constant time operation.
   263     int countTrue() { return imap.countTrue(); }
   264     ///Number of \c false items in the map
   265 
   266     ///Returns the number of \c false values in the map.
   267     ///This is a constant time operation.
   268     int countFalse() { return imap.countFalse(); }
   269 #ifdef DOXYGEN
   270     ///\e
   271     bool &operator[](Key k) { return imap[k];}  
   272     ///\e
   273     const bool &operator[](Key k) const { return imap[k];}  
   274 #else
   275     Value operator[](Key k) const { return imap[k];}  
   276     RefType operator[](Key k) { return imap[k];}  
   277 #endif
   278     ///Iterator for the "false" edges
   279     class FalseIt : public BimType::FalseIt
   280     {
   281     public:
   282       ///\e
   283       explicit FalseIt(const IterableBoolEdgeMap &m)
   284 	: BimType::FalseIt(m.imap) { }
   285       ///\e
   286       FalseIt(Invalid i) : BimType::FalseIt(i) { }
   287     };
   288     ///Iterator for the "true" edges
   289     class TrueIt : public BimType::TrueIt
   290     {
   291     public:
   292       ///\e
   293       explicit TrueIt(const IterableBoolEdgeMap &m)
   294 	: BimType::TrueIt(m.imap) { }
   295       ///\e
   296       TrueIt(Invalid i) : BimType::TrueIt(i) { }
   297     };  
   298   };
   299 
   300 
   301   namespace _iterable_maps_bits {
   302     template <typename Item>
   303     struct IterableIntMapNode {
   304       IterableIntMapNode() {}
   305       IterableIntMapNode(int _value) : value(_value) {}
   306       Item prev, next;
   307       int value;
   308     };
   309   }
   310 
   311   ///\ingroup maps
   312   ///
   313   /// \brief Dynamic iterable integer map.
   314   ///
   315   /// This class provides a special graph map type which can store
   316   /// for each graph item(node, edge, etc.) an integer value. For each
   317   /// non negative value it is possible to iterate on the keys which
   318   /// mapped to the given value.
   319   /// 
   320   /// \param _Graph The graph type.
   321   /// \param _Item One of the graph's item type, the key of the map.
   322   template <typename _Graph, typename _Item>
   323   class IterableIntMap : protected ItemSetTraits<_Graph, _Item> 
   324   ::template Map<_iterable_maps_bits::IterableIntMapNode<_Item> >::Parent {
   325   public:
   326     typedef typename ItemSetTraits<_Graph, _Item> 
   327     ::template Map<_iterable_maps_bits::IterableIntMapNode<_Item> >
   328     ::Parent Parent;
   329 
   330     /// The key type
   331     typedef _Item Key;
   332     /// The value type
   333     typedef int Value;
   334     /// The graph type
   335     typedef _Graph Graph;
   336 
   337     /// \brief Constructor of the Map.
   338     ///
   339     /// Constructor of the Map. It set all values -1.
   340     explicit IterableIntMap(const Graph& graph) 
   341       : Parent(graph, _iterable_maps_bits::IterableIntMapNode<_Item>(-1)) {}
   342 
   343     /// \brief Constructor of the Map with a given value.
   344     ///
   345     /// Constructor of the Map with a given value.
   346     explicit IterableIntMap(const Graph& graph, int value) 
   347       : Parent(graph, _iterable_maps_bits::IterableIntMapNode<_Item>(value)) {
   348       if (value >= 0) {
   349 	for (typename Parent::ItemIt it(*this); it != INVALID; ++it) {
   350 	  lace(it);
   351 	}
   352       }
   353     }
   354 
   355   private:
   356     
   357     void unlace(const Key& key) {
   358       typename Parent::Value& node = Parent::operator[](key);
   359       if (node.value < 0) return;
   360       if (node.prev != INVALID) {
   361 	Parent::operator[](node.prev).next = node.next;	
   362       } else {
   363 	first[node.value] = node.next;
   364       }
   365       if (node.next != INVALID) {
   366 	Parent::operator[](node.next).prev = node.prev;
   367       }
   368       while (!first.empty() && first.back() == INVALID) {
   369 	first.pop_back();
   370       }
   371     }
   372 
   373     void lace(const Key& key) {
   374       typename Parent::Value& node = Parent::operator[](key);
   375       if (node.value < 0) return;
   376       if (node.value >= (int)first.size()) {
   377 	first.resize(node.value + 1, INVALID);
   378       } 
   379       node.prev = INVALID;
   380       node.next = first[node.value];
   381       if (node.next != INVALID) {
   382 	Parent::operator[](node.next).prev = key;	
   383       }
   384       first[node.value] = key;
   385     }
   386 
   387   public:
   388 
   389     /// Indicates that the map if reference map.
   390     typedef True ReferenceMapTag;
   391 
   392     /// \brief Refernce to the value of the map.
   393     ///
   394     /// This class is near to similar to the int type. It can
   395     /// be converted to int and it has the same operators.
   396     class Reference {
   397       friend class IterableIntMap;
   398     private:
   399       Reference(IterableIntMap& map, const Key& key) 
   400 	: _key(key), _map(map) {} 
   401     public:
   402 
   403       Reference& operator=(const Reference& value) {
   404 	_map.set(_key, (const int&)value);
   405  	return *this;
   406       }
   407 
   408       operator const int&() const { 
   409 	return static_cast<const IterableIntMap&>(_map)[_key]; 
   410       }
   411 
   412       Reference& operator=(int value) { 
   413 	_map.set(_key, value); 
   414 	return *this; 
   415       }
   416       Reference& operator++() {
   417 	_map.set(_key, _map[_key] + 1); 
   418 	return *this; 	
   419       }
   420       int operator++(int) {
   421 	int value = _map[_key];
   422 	_map.set(_key, value + 1); 
   423 	return value; 	
   424       }
   425       Reference& operator--() {
   426 	_map.set(_key, _map[_key] - 1); 
   427 	return *this; 	
   428       }
   429       int operator--(int) {
   430 	int value = _map[_key];
   431 	_map.set(_key, value - 1); 
   432 	return value; 	
   433       }
   434       Reference& operator+=(int value) { 
   435 	_map.set(_key, _map[_key] + value); 
   436 	return *this;
   437       }
   438       Reference& operator-=(int value) { 
   439 	_map.set(_key, _map[_key] - value); 
   440 	return *this;
   441       }
   442       Reference& operator*=(int value) { 
   443 	_map.set(_key, _map[_key] * value); 
   444 	return *this;
   445       }
   446       Reference& operator/=(int value) { 
   447 	_map.set(_key, _map[_key] / value); 
   448 	return *this;
   449       }
   450       Reference& operator%=(int value) { 
   451 	_map.set(_key, _map[_key] % value); 
   452 	return *this;
   453       }
   454       Reference& operator&=(int value) { 
   455 	_map.set(_key, _map[_key] & value); 
   456 	return *this;
   457       }
   458       Reference& operator|=(int value) { 
   459 	_map.set(_key, _map[_key] | value); 
   460 	return *this;
   461       }
   462       Reference& operator^=(int value) { 
   463 	_map.set(_key, _map[_key] ^ value); 
   464 	return *this;
   465       }
   466       Reference& operator<<=(int value) { 
   467 	_map.set(_key, _map[_key] << value); 
   468 	return *this;
   469       }
   470       Reference& operator>>=(int value) { 
   471 	_map.set(_key, _map[_key] >> value); 
   472 	return *this;
   473       }
   474 
   475     private:
   476       Key _key;
   477       IterableIntMap& _map; 
   478     };
   479 
   480     /// The const reference type.    
   481     typedef const Value& ConstReference;
   482 
   483     /// \brief Gives back the maximal value plus one.
   484     ///
   485     /// Gives back the maximal value plus one.
   486     int size() const {
   487       return (int)first.size();
   488     }
   489     
   490     /// \brief Set operation of the map.
   491     ///
   492     /// Set operation of the map.
   493     void set(const Key& key, const Value& value) {
   494       unlace(key);
   495       Parent::operator[](key).value = value;
   496       lace(key);
   497     }
   498 
   499     /// \brief Const subscript operator of the map.
   500     ///
   501     /// Const subscript operator of the map.
   502     const Value& operator[](const Key& key) const {
   503       return Parent::operator[](key).value;
   504     }
   505 
   506     /// \brief Subscript operator of the map.
   507     ///
   508     /// Subscript operator of the map.
   509     Reference operator[](const Key& key) {
   510       return Reference(*this, key);
   511     }
   512 
   513     /// \brief Iterator for the keys with the same value.
   514     ///
   515     /// Iterator for the keys with the same value. It works
   516     /// like a graph item iterator in the map, it can be converted
   517     /// the item type of the map, incremented with \c ++ operator, and
   518     /// if the iterator leave the last valid item it will be equal to 
   519     /// \c INVALID.
   520     class ItemIt : public _Item {
   521     public:
   522       typedef _Item Parent;
   523 
   524       /// \brief Invalid constructor \& conversion.
   525       ///
   526       /// This constructor initializes the item to be invalid.
   527       /// \sa Invalid for more details.
   528       ItemIt(Invalid) : Parent(INVALID), _map(0) {}
   529 
   530       /// \brief Creates an iterator with a value.
   531       ///
   532       /// Creates an iterator with a value. It iterates on the 
   533       /// keys which have the given value.
   534       /// \param map The IterableIntMap
   535       /// \param value The value
   536       ItemIt(const IterableIntMap& map, int value) : _map(&map) {
   537 	if (value < 0 || value >= (int)_map->first.size()) {	  
   538 	  Parent::operator=(INVALID);
   539 	} else {
   540 	  Parent::operator=(_map->first[value]);
   541 	}
   542       } 
   543 
   544       /// \brief Increment operator.
   545       ///
   546       /// Increment Operator.
   547       ItemIt& operator++() {
   548 	Parent::operator=(_map->IterableIntMap::Parent::
   549 			  operator[](static_cast<Parent&>(*this)).next);
   550 	return *this;
   551       }
   552 
   553 
   554     private:
   555       const IterableIntMap* _map;
   556     };
   557 
   558   protected:
   559     
   560     virtual void erase(const Key& key) {
   561       unlace(key);
   562       Parent::erase(key);
   563     }
   564 
   565     virtual void clear() {
   566       first.clear();
   567       Parent::clear();
   568     }
   569 
   570   private:
   571     std::vector<_Item> first;
   572   };
   573 
   574   /// @}
   575 }