klao@39: /* FIXME: Copyright ... 
klao@39:  *
klao@39:  * This implementation is heavily based on STL's heap functions and
klao@39:  * the similar class by Alpar Juttner in IKTA...
klao@39:  */
klao@39: 
klao@39: /******
klao@39:  *
klao@39:  * BinHeap<KeyType, ValueType, KeyIntMap, [ValueCompare]>
klao@39:  *
klao@39:  * Ez az osztaly kulcs-ertek parok tarolasara alkalmas binaris kupacot
klao@39:  * valosit meg.
klao@39:  * A kupacban legfolul mindig az a par talalhato, amiben az _ertek_ a
klao@39:  * legkisebb. (Gondolj a Dijkstra pont-tavolsag kupacara; igazabol ahhoz
klao@39:  * lett keszitve...)
klao@39:  *
klao@39:  * Megjegyzes: egy kicsit gyanus nekem, hogy a kupacos temakorben nem
klao@39:  * azt hivjak kulcsnak, amit most en annak nevezek. :) En olyan 
klao@39:  * property_map -os ertelemben hasznalom.
klao@39:  *
klao@39:  * A hasznalatahoz szukseg van egy irhato/olvashato property_map-re, ami
klao@39:  * a kulcsokhoz egy int-et tud tarolni (ezzel tudom megkeresni az illeto
klao@39:  * elemet a kupacban a csokkentes es hasonlo muveletekhez).
klao@39:  * A map-re csak referenciat tarol, ugy hogy a kupac elete folyan a map-nek
klao@39:  * is elnie kell. (???)
klao@39:  *
klao@39:  * Ketfele modon hasznalhato:
klao@39:  * Lusta mod:
klao@39:  * put(Key, Value) metodussal pakolunk a kupacba,
klao@39:  * aztan o majd eldonti, hogy ez az elem mar benne van-e es ha igen, akkor
klao@39:  * csokkentettunk-e rajta, vagy noveltunk.
klao@39:  * Ehhez nagyon fontos, hogy az atadott property map inicializalva legyen
klao@39:  * minden szobajovo kulcs ertekre, -1 -es ertekkel!
klao@39:  * Es ilyen esetben a kulcsokrol lekerdezheto az allapotuk a state metodussal:
klao@39:  * (nem jart meg a kupacban PRE_HEAP=-1, epp a kupacban van IN_HEAP=0,
klao@39:  *  mar kikerult a kupacbol POST_HEAP=-2).
klao@39:  * Szoval ebben a modban a kupac nagyjabol hasznalhato property_map-kent, csak
klao@39:  * meg meg tudja mondani a "legkisebb" erteku elemet. De csak nagyjabol,
klao@39:  * hiszen a kupacbol kikerult elemeknek elvesz az ertekuk...
klao@39:  *
klao@39:  * Kozvetlen mod:
klao@39:  * push(Key, Value) metodussal belerakunk a kupacba (ha az illeto kulcs mar
klao@39:  * benn volt, akkor gaz).
klao@39:  * increase/decrease(Key k, Value new_value) metodusokkal lehet
klao@39:  * novelni/csokkenteni az illeto kulcshoz tartozo erteket. (Ha nem volt meg
klao@39:  * benne a kupacban az illeto kulcs, vagy nem abba az iranyba valtoztattad
klao@39:  * az erteket, amerre mondtad -- gaz).
klao@39:  *
klao@39:  * Termeszetesen a fenti ket modot ertelemszeruen lehet keverni.
klao@39:  * Ja es mindig nagyon gaz, ha belepiszkalsz a map-be, amit a kupac
klao@39:  * hasznal. :-))
klao@39:  *
klao@39:  *
klao@39:  * Bocs, most faradt vagyok, majd egyszer leforditom. (Misi)
klao@39:  *
klao@39:  */
klao@39: 
klao@39: 
klao@37: #ifndef BIN_HEAP_HH
klao@37: #define BIN_HEAP_HH
klao@37: 
klao@37: #include <vector>
klao@37: #include <utility>
klao@37: #include <functional>
klao@37: 
alpar@114: namespace hugo {
klao@37: 
klao@37:   template <typename Key, typename Val, typename KeyIntMap,
klao@37: 	    typename Compare = std::less<Val> >
klao@37:   class BinHeap {
klao@37: 
klao@37:   public:
klao@37:     typedef Key	             KeyType;
klao@37:     // FIXME: stl-ben nem ezt hivjak value_type -nak, hanem a kovetkezot...
klao@37:     typedef Val              ValueType;
klao@37:     typedef std::pair<KeyType,ValueType>     PairType;
klao@37:     typedef KeyIntMap        KeyIntMapType;
klao@37:     typedef Compare          ValueCompare;
klao@37: 
klao@37:     /**
klao@37:      * Each Key element have a state associated to it. It may be "in heap",
klao@37:      * "pre heap" or "post heap". The later two are indifferent from the
klao@37:      * heap's point of view, but may be useful to the user.
klao@37:      *
klao@37:      * The KeyIntMap _should_ be initialized in such way, that it maps
klao@37:      * PRE_HEAP (-1) to any element to be put in the heap...
klao@37:      */
klao@39:     enum state_enum {
klao@37:       IN_HEAP = 0,
klao@37:       PRE_HEAP = -1,
klao@37:       POST_HEAP = -2
klao@37:     };
klao@37: 
klao@37:   private:
klao@37:     std::vector<PairType> data;
klao@37:     Compare comp;
klao@37:     // FIXME: jo ez igy???
klao@37:     KeyIntMap &kim;
klao@37: 
klao@37:   public:
klao@37:     BinHeap(KeyIntMap &_kim) : kim(_kim) {}
klao@37:     BinHeap(KeyIntMap &_kim, const Compare &_comp) : comp(_comp), kim(_kim) {}
klao@37: 
klao@37: 
klao@37:     int size() const { return data.size(); }
klao@41:     bool empty() const { return data.empty(); }
klao@37: 
klao@37:   private:
klao@37:     static int parent(int i) { return (i-1)/2; }
klao@37:     static int second_child(int i) { return 2*i+2; }
klao@37:     bool less(const PairType &p1, const PairType &p2) {
klao@37:       return comp(p1.second, p2.second);
klao@37:     }
klao@37: 
klao@37:     int bubble_up(int hole, PairType p);
klao@37:     int bubble_down(int hole, PairType p, int length);
klao@37: 
klao@37:     void move(const PairType &p, int i) {
klao@37:       data[i] = p;
klao@37:       kim.put(p.first, i);
klao@37:     }
klao@37: 
klao@41:     void rmidx(int h) {
klao@41:       int n = data.size()-1;
klao@41:       if( h>=0 && h<=n ) {
klao@41: 	kim.put(data[h].first, POST_HEAP);
klao@41: 	if ( h<n ) {
klao@41: 	  bubble_down(h, data[n], n);
klao@41: 	}
klao@41: 	data.pop_back();
klao@41:       }
klao@41:     }
klao@41: 
klao@37:   public:
klao@37:     void push(const PairType &p) {
klao@37:       int n = data.size();
klao@37:       data.resize(n+1);
klao@37:       bubble_up(n, p);
klao@37:     }
klao@37:     void push(const Key &k, const Val &v) { push(PairType(k,v)); }
klao@37: 
klao@37:     Key top() const {
klao@37:       // FIXME: test size>0 ?
klao@37:       return data[0].first;
klao@37:     }
klao@37:     Val topValue() const {
klao@37:       // FIXME: test size>0 ?
klao@37:       return data[0].second;
klao@37:     }
klao@37: 
klao@37:     void pop() {
klao@41:       rmidx(0);
klao@41:     }
klao@41: 
klao@41:     void erase(const Key &k) {
klao@41:       rmidx(kim.get(k));
klao@37:     }
klao@37: 
klao@37:     const Val get(const Key &k) const {
klao@37:       int idx = kim.get(k);
klao@37:       return data[idx].second;
klao@37:     }
klao@37:     void put(const Key &k, const Val &v) {
klao@37:       int idx = kim.get(k);
klao@37:       if( idx < 0 ) {
klao@37: 	push(k,v);
klao@37:       }
klao@37:       else if( comp(v, data[idx].second) ) {
klao@37: 	bubble_up(idx, PairType(k,v));
klao@37:       }
klao@37:       else {
klao@37: 	bubble_down(idx, PairType(k,v), data.size());
klao@37:       }
klao@37:     }
klao@37: 
klao@37:     void decrease(const Key &k, const Val &v) {
klao@37:       int idx = kim.get(k);
klao@37:       bubble_up(idx, PairType(k,v));
klao@37:     }
klao@37:     void increase(const Key &k, const Val &v) {
klao@37:       int idx = kim.get(k);
klao@37:       bubble_down(idx, PairType(k,v), data.size());
klao@37:     }
klao@37: 
klao@39:     state_enum state(const Key &k) const {
klao@39:       int s = kim.get(k);
klao@39:       if( s>=0 )
klao@39: 	s=0;
klao@39:       return state_enum(s);
klao@39:     }
klao@39: 
klao@37:   }; // class BinHeap
klao@37: 
klao@37:   
klao@37:   template <typename K, typename V, typename M, typename C>
klao@37:   int BinHeap<K,V,M,C>::bubble_up(int hole, PairType p) {
klao@37:     int par = parent(hole);
klao@37:     while( hole>0 && less(p,data[par]) ) {
klao@37:       move(data[par],hole);
klao@37:       hole = par;
klao@37:       par = parent(hole);
klao@37:     }
klao@37:     move(p, hole);
klao@37:     return hole;
klao@37:   }
klao@37: 
klao@37:   template <typename K, typename V, typename M, typename C>
klao@37:   int BinHeap<K,V,M,C>::bubble_down(int hole, PairType p, int length) {
klao@37:     int child = second_child(hole);
klao@37:     while(child < length) {
klao@37:       if( less(data[child-1], data[child]) ) {
klao@37: 	--child;
klao@37:       }
klao@37:       if( !less(data[child], p) )
klao@37: 	goto ok;
klao@37:       move(data[child], hole);
klao@37:       hole = child;
klao@37:       child = second_child(hole);
klao@37:     }
klao@37:     child--;
klao@37:     if( child<length && less(data[child], p) ) {
klao@37:       move(data[child], hole);
klao@37:       hole=child;
klao@37:     }
klao@37:   ok:
klao@37:     move(p, hole);
klao@37:     return hole;
klao@37:   }
klao@37: 
alpar@114: } // namespace hugo
klao@37: 
klao@37: #endif // BIN_HEAP_HH