deba@2038: /* -*- C++ -*-
deba@2038: *
deba@2038: * This file is a part of LEMON, a generic C++ optimization library
deba@2038: *
deba@2038: * Copyright (C) 2003-2006
deba@2038: * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
deba@2038: * (Egervary Research Group on Combinatorial Optimization, EGRES).
deba@2038: *
deba@2038: * Permission to use, modify and distribute this software is granted
deba@2038: * provided that this copyright notice appears in all copies. For
deba@2038: * precise terms see the accompanying LICENSE file.
deba@2038: *
deba@2038: * This software is provided "AS IS" with no warranty of any kind,
deba@2038: * express or implied, and with no claim as to its suitability for any
deba@2038: * purpose.
deba@2038: *
deba@2038: */
deba@2038:
deba@2038: #ifndef LEMON_BUCKET_HEAP_H
deba@2038: #define LEMON_BUCKET_HEAP_H
deba@2038:
deba@2038: ///\ingroup auxdat
deba@2038: ///\file
deba@2038: ///\brief Bucket Heap implementation.
deba@2038:
deba@2038: #include <vector>
deba@2038: #include <utility>
deba@2038: #include <functional>
deba@2038:
deba@2038: namespace lemon {
deba@2038:
deba@2038: /// \ingroup auxdat
deba@2089: ///
deba@2038: /// \brief A Bucket Heap implementation.
deba@2038: ///
deba@2038: /// This class implements the \e bucket \e heap data structure. A \e heap
deba@2038: /// is a data structure for storing items with specified values called \e
deba@2038: /// priorities in such a way that finding the item with minimum priority is
deba@2038: /// efficient. The bucket heap is very simple implementation, it can store
deba@2042: /// only integer priorities and it stores for each priority in the
deba@2042: /// \f$ [0..C) \f$ range a list of items. So it should be used only when
deba@2042: /// the priorities are small. It is not intended to use as dijkstra heap.
deba@2038: ///
deba@2038: /// \param _ItemIntMap A read and writable Item int map, used internally
deba@2038: /// to handle the cross references.
deba@2038: /// \param minimize If the given parameter is true then the heap gives back
deba@2038: /// the lowest priority.
mqrelly@2263: template <typename _ItemIntMap, bool minimize = true >
deba@2038: class BucketHeap {
deba@2038:
deba@2038: public:
mqrelly@2263: typedef typename _ItemIntMap::Key Item;
deba@2038: typedef int Prio;
deba@2038: typedef std::pair<Item, Prio> Pair;
deba@2038: typedef _ItemIntMap ItemIntMap;
deba@2038:
deba@2038: /// \brief Type to represent the items states.
deba@2038: ///
deba@2038: /// Each Item element have a state associated to it. It may be "in heap",
deba@2038: /// "pre heap" or "post heap". The latter two are indifferent from the
deba@2038: /// heap's point of view, but may be useful to the user.
deba@2038: ///
deba@2038: /// The ItemIntMap \e should be initialized in such way that it maps
deba@2038: /// PRE_HEAP (-1) to any element to be put in the heap...
deba@2038: enum state_enum {
deba@2038: IN_HEAP = 0,
deba@2038: PRE_HEAP = -1,
deba@2038: POST_HEAP = -2
deba@2038: };
deba@2038:
deba@2038: public:
deba@2038: /// \brief The constructor.
deba@2038: ///
deba@2038: /// The constructor.
deba@2038: /// \param _index should be given to the constructor, since it is used
deba@2038: /// internally to handle the cross references. The value of the map
deba@2038: /// should be PRE_HEAP (-1) for each element.
deba@2038: explicit BucketHeap(ItemIntMap &_index) : index(_index), minimal(0) {}
deba@2038:
deba@2038: /// The number of items stored in the heap.
deba@2038: ///
deba@2038: /// \brief Returns the number of items stored in the heap.
deba@2038: int size() const { return data.size(); }
deba@2038:
deba@2038: /// \brief Checks if the heap stores no items.
deba@2038: ///
deba@2038: /// Returns \c true if and only if the heap stores no items.
deba@2038: bool empty() const { return data.empty(); }
deba@2038:
deba@2038: /// \brief Make empty this heap.
deba@2038: ///
deba@2050: /// Make empty this heap. It does not change the cross reference
deba@2050: /// map. If you want to reuse a heap what is not surely empty you
deba@2050: /// should first clear the heap and after that you should set the
deba@2050: /// cross reference map for each item to \c PRE_HEAP.
deba@2038: void clear() {
deba@2038: data.clear(); first.clear(); minimal = 0;
deba@2038: }
deba@2038:
deba@2038: private:
deba@2038:
deba@2038: void relocate_last(int idx) {
deba@2038: if (idx + 1 < (int)data.size()) {
deba@2038: data[idx] = data.back();
deba@2038: if (data[idx].prev != -1) {
deba@2038: data[data[idx].prev].next = idx;
deba@2038: } else {
deba@2038: first[data[idx].value] = idx;
deba@2038: }
deba@2038: if (data[idx].next != -1) {
deba@2038: data[data[idx].next].prev = idx;
deba@2038: }
deba@2038: index[data[idx].item] = idx;
deba@2038: }
deba@2038: data.pop_back();
deba@2038: }
deba@2038:
deba@2038: void unlace(int idx) {
deba@2038: if (data[idx].prev != -1) {
deba@2038: data[data[idx].prev].next = data[idx].next;
deba@2038: } else {
deba@2038: first[data[idx].value] = data[idx].next;
deba@2038: }
deba@2038: if (data[idx].next != -1) {
deba@2038: data[data[idx].next].prev = data[idx].prev;
deba@2038: }
deba@2038: }
deba@2038:
deba@2038: void lace(int idx) {
deba@2038: if ((int)first.size() <= data[idx].value) {
deba@2038: first.resize(data[idx].value + 1, -1);
deba@2038: }
deba@2038: data[idx].next = first[data[idx].value];
deba@2038: if (data[idx].next != -1) {
deba@2038: data[data[idx].next].prev = idx;
deba@2038: }
deba@2038: first[data[idx].value] = idx;
deba@2038: data[idx].prev = -1;
deba@2038: }
deba@2038:
deba@2038: public:
deba@2038: /// \brief Insert a pair of item and priority into the heap.
deba@2038: ///
deba@2038: /// Adds \c p.first to the heap with priority \c p.second.
deba@2038: /// \param p The pair to insert.
deba@2038: void push(const Pair& p) {
deba@2038: push(p.first, p.second);
deba@2038: }
deba@2038:
deba@2038: /// \brief Insert an item into the heap with the given priority.
deba@2038: ///
deba@2038: /// Adds \c i to the heap with priority \c p.
deba@2038: /// \param i The item to insert.
deba@2038: /// \param p The priority of the item.
deba@2038: void push(const Item &i, const Prio &p) {
deba@2038: int idx = data.size();
deba@2038: index[i] = idx;
deba@2038: data.push_back(BucketItem(i, p));
deba@2038: lace(idx);
deba@2038: if (p < minimal) {
deba@2038: minimal = p;
deba@2038: }
deba@2038: }
deba@2038:
deba@2038: /// \brief Returns the item with minimum priority.
deba@2038: ///
deba@2038: /// This method returns the item with minimum priority.
deba@2038: /// \pre The heap must be nonempty.
deba@2038: Item top() const {
deba@2038: while (first[minimal] == -1) {
deba@2038: ++minimal;
deba@2038: }
deba@2038: return data[first[minimal]].item;
deba@2038: }
deba@2038:
deba@2038: /// \brief Returns the minimum priority.
deba@2038: ///
deba@2038: /// It returns the minimum priority.
deba@2038: /// \pre The heap must be nonempty.
deba@2038: Prio prio() const {
deba@2038: while (first[minimal] == -1) {
deba@2038: ++minimal;
deba@2038: }
deba@2038: return minimal;
deba@2038: }
deba@2038:
deba@2038: /// \brief Deletes the item with minimum priority.
deba@2038: ///
deba@2038: /// This method deletes the item with minimum priority from the heap.
deba@2038: /// \pre The heap must be non-empty.
deba@2038: void pop() {
deba@2038: while (first[minimal] == -1) {
deba@2038: ++minimal;
deba@2038: }
deba@2038: int idx = first[minimal];
deba@2038: index[data[idx].item] = -2;
deba@2038: unlace(idx);
deba@2038: relocate_last(idx);
deba@2038: }
deba@2038:
deba@2038: /// \brief Deletes \c i from the heap.
deba@2038: ///
deba@2038: /// This method deletes item \c i from the heap, if \c i was
deba@2038: /// already stored in the heap.
deba@2038: /// \param i The item to erase.
deba@2038: void erase(const Item &i) {
deba@2038: int idx = index[i];
deba@2038: index[data[idx].item] = -2;
deba@2038: unlace(idx);
deba@2038: relocate_last(idx);
deba@2038: }
deba@2038:
deba@2038:
deba@2038: /// \brief Returns the priority of \c i.
deba@2038: ///
deba@2038: /// This function returns the priority of item \c i.
deba@2038: /// \pre \c i must be in the heap.
deba@2038: /// \param i The item.
deba@2038: Prio operator[](const Item &i) const {
deba@2038: int idx = index[i];
deba@2038: return data[idx].value;
deba@2038: }
deba@2038:
deba@2038: /// \brief \c i gets to the heap with priority \c p independently
deba@2038: /// if \c i was already there.
deba@2038: ///
deba@2038: /// This method calls \ref push(\c i, \c p) if \c i is not stored
deba@2038: /// in the heap and sets the priority of \c i to \c p otherwise.
deba@2038: /// \param i The item.
deba@2038: /// \param p The priority.
deba@2038: void set(const Item &i, const Prio &p) {
deba@2038: int idx = index[i];
deba@2038: if (idx < 0) {
deba@2038: push(i,p);
deba@2038: } else if (p > data[idx].value) {
deba@2038: increase(i, p);
deba@2038: } else {
deba@2038: decrease(i, p);
deba@2038: }
deba@2038: }
deba@2038:
deba@2038: /// \brief Decreases the priority of \c i to \c p.
deba@2089: ///
deba@2038: /// This method decreases the priority of item \c i to \c p.
deba@2038: /// \pre \c i must be stored in the heap with priority at least \c
deba@2038: /// p relative to \c Compare.
deba@2038: /// \param i The item.
deba@2038: /// \param p The priority.
deba@2038: void decrease(const Item &i, const Prio &p) {
deba@2038: int idx = index[i];
deba@2038: unlace(idx);
deba@2038: data[idx].value = p;
deba@2038: if (p < minimal) {
deba@2038: minimal = p;
deba@2038: }
deba@2038: lace(idx);
deba@2038: }
deba@2038:
deba@2038: /// \brief Increases the priority of \c i to \c p.
deba@2038: ///
deba@2038: /// This method sets the priority of item \c i to \c p.
deba@2038: /// \pre \c i must be stored in the heap with priority at most \c
deba@2038: /// p relative to \c Compare.
deba@2038: /// \param i The item.
deba@2038: /// \param p The priority.
deba@2038: void increase(const Item &i, const Prio &p) {
deba@2038: int idx = index[i];
deba@2038: unlace(idx);
deba@2038: data[idx].value = p;
deba@2038: lace(idx);
deba@2038: }
deba@2038:
deba@2038: /// \brief Returns if \c item is in, has already been in, or has
deba@2038: /// never been in the heap.
deba@2038: ///
deba@2038: /// This method returns PRE_HEAP if \c item has never been in the
deba@2038: /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
deba@2038: /// otherwise. In the latter case it is possible that \c item will
deba@2038: /// get back to the heap again.
deba@2038: /// \param i The item.
deba@2038: state_enum state(const Item &i) const {
deba@2038: int idx = index[i];
deba@2038: if (idx >= 0) idx = 0;
deba@2038: return state_enum(idx);
deba@2038: }
deba@2038:
deba@2038: /// \brief Sets the state of the \c item in the heap.
deba@2038: ///
deba@2038: /// Sets the state of the \c item in the heap. It can be used to
deba@2038: /// manually clear the heap when it is important to achive the
deba@2038: /// better time complexity.
deba@2038: /// \param i The item.
deba@2038: /// \param st The state. It should not be \c IN_HEAP.
deba@2038: void state(const Item& i, state_enum st) {
deba@2038: switch (st) {
deba@2038: case POST_HEAP:
deba@2038: case PRE_HEAP:
deba@2038: if (state(i) == IN_HEAP) {
deba@2038: erase(i);
deba@2038: }
deba@2038: index[i] = st;
deba@2038: break;
deba@2038: case IN_HEAP:
deba@2038: break;
deba@2038: }
deba@2038: }
deba@2038:
deba@2038: private:
deba@2038:
deba@2038: struct BucketItem {
deba@2038: BucketItem(const Item& _item, int _value)
deba@2038: : item(_item), value(_value) {}
deba@2038:
deba@2038: Item item;
deba@2038: int value;
deba@2038:
deba@2038: int prev, next;
deba@2038: };
deba@2038:
deba@2038: ItemIntMap& index;
deba@2038: std::vector<int> first;
deba@2038: std::vector<BucketItem> data;
deba@2038: mutable int minimal;
deba@2038:
deba@2038: }; // class BucketHeap
deba@2038:
deba@2038:
mqrelly@2263: template <typename _ItemIntMap>
mqrelly@2263: class BucketHeap<_ItemIntMap, false> {
deba@2038:
deba@2038: public:
mqrelly@2263: typedef typename _ItemIntMap::Key Item;
deba@2038: typedef int Prio;
deba@2038: typedef std::pair<Item, Prio> Pair;
deba@2038: typedef _ItemIntMap ItemIntMap;
deba@2038:
deba@2038: enum state_enum {
deba@2038: IN_HEAP = 0,
deba@2038: PRE_HEAP = -1,
deba@2038: POST_HEAP = -2
deba@2038: };
deba@2038:
deba@2038: public:
deba@2038:
deba@2038: explicit BucketHeap(ItemIntMap &_index) : index(_index), maximal(-1) {}
deba@2038:
deba@2038: int size() const { return data.size(); }
deba@2038: bool empty() const { return data.empty(); }
deba@2038:
deba@2038: void clear() {
deba@2038: data.clear(); first.clear(); maximal = -1;
deba@2038: }
deba@2038:
deba@2038: private:
deba@2038:
deba@2038: void relocate_last(int idx) {
deba@2038: if (idx + 1 != (int)data.size()) {
deba@2038: data[idx] = data.back();
deba@2038: if (data[idx].prev != -1) {
deba@2038: data[data[idx].prev].next = idx;
deba@2038: } else {
deba@2038: first[data[idx].value] = idx;
deba@2038: }
deba@2038: if (data[idx].next != -1) {
deba@2038: data[data[idx].next].prev = idx;
deba@2038: }
deba@2038: index[data[idx].item] = idx;
deba@2038: }
deba@2038: data.pop_back();
deba@2038: }
deba@2038:
deba@2038: void unlace(int idx) {
deba@2038: if (data[idx].prev != -1) {
deba@2038: data[data[idx].prev].next = data[idx].next;
deba@2038: } else {
deba@2038: first[data[idx].value] = data[idx].next;
deba@2038: }
deba@2038: if (data[idx].next != -1) {
deba@2038: data[data[idx].next].prev = data[idx].prev;
deba@2038: }
deba@2038: }
deba@2038:
deba@2038: void lace(int idx) {
deba@2038: if ((int)first.size() <= data[idx].value) {
deba@2038: first.resize(data[idx].value + 1, -1);
deba@2038: }
deba@2038: data[idx].next = first[data[idx].value];
deba@2038: if (data[idx].next != -1) {
deba@2038: data[data[idx].next].prev = idx;
deba@2038: }
deba@2038: first[data[idx].value] = idx;
deba@2038: data[idx].prev = -1;
deba@2038: }
deba@2038:
deba@2038: public:
deba@2038:
deba@2038: void push(const Pair& p) {
deba@2038: push(p.first, p.second);
deba@2038: }
deba@2038:
deba@2038: void push(const Item &i, const Prio &p) {
deba@2038: int idx = data.size();
deba@2038: index[i] = idx;
deba@2038: data.push_back(BucketItem(i, p));
deba@2038: lace(idx);
deba@2038: if (data[idx].value > maximal) {
deba@2038: maximal = data[idx].value;
deba@2038: }
deba@2038: }
deba@2038:
deba@2038: Item top() const {
deba@2038: while (first[maximal] == -1) {
deba@2038: --maximal;
deba@2038: }
deba@2038: return data[first[maximal]].item;
deba@2038: }
deba@2038:
deba@2038: Prio prio() const {
deba@2038: while (first[maximal] == -1) {
deba@2038: --maximal;
deba@2038: }
deba@2038: return maximal;
deba@2038: }
deba@2038:
deba@2038: void pop() {
deba@2038: while (first[maximal] == -1) {
deba@2038: --maximal;
deba@2038: }
deba@2038: int idx = first[maximal];
deba@2038: index[data[idx].item] = -2;
deba@2038: unlace(idx);
deba@2038: relocate_last(idx);
deba@2038: }
deba@2038:
deba@2038: void erase(const Item &i) {
deba@2038: int idx = index[i];
deba@2038: index[data[idx].item] = -2;
deba@2038: unlace(idx);
deba@2038: relocate_last(idx);
deba@2038: }
deba@2038:
deba@2038: Prio operator[](const Item &i) const {
deba@2038: int idx = index[i];
deba@2038: return data[idx].value;
deba@2038: }
deba@2038:
deba@2038: void set(const Item &i, const Prio &p) {
deba@2038: int idx = index[i];
deba@2038: if (idx < 0) {
deba@2038: push(i,p);
deba@2038: } else if (p > data[idx].value) {
deba@2038: decrease(i, p);
deba@2038: } else {
deba@2038: increase(i, p);
deba@2038: }
deba@2038: }
deba@2038:
deba@2038: void decrease(const Item &i, const Prio &p) {
deba@2038: int idx = index[i];
deba@2038: unlace(idx);
deba@2038: data[idx].value = p;
deba@2038: if (p > maximal) {
deba@2038: maximal = p;
deba@2038: }
deba@2038: lace(idx);
deba@2038: }
deba@2038:
deba@2038: void increase(const Item &i, const Prio &p) {
deba@2038: int idx = index[i];
deba@2038: unlace(idx);
deba@2038: data[idx].value = p;
deba@2038: lace(idx);
deba@2038: }
deba@2038:
deba@2038: state_enum state(const Item &i) const {
deba@2038: int idx = index[i];
deba@2038: if (idx >= 0) idx = 0;
deba@2038: return state_enum(idx);
deba@2038: }
deba@2038:
deba@2038: void state(const Item& i, state_enum st) {
deba@2038: switch (st) {
deba@2038: case POST_HEAP:
deba@2038: case PRE_HEAP:
deba@2038: if (state(i) == IN_HEAP) {
deba@2038: erase(i);
deba@2038: }
deba@2038: index[i] = st;
deba@2038: break;
deba@2038: case IN_HEAP:
deba@2038: break;
deba@2038: }
deba@2038: }
deba@2038:
deba@2038: private:
deba@2038:
deba@2038: struct BucketItem {
deba@2038: BucketItem(const Item& _item, int _value)
deba@2038: : item(_item), value(_value) {}
deba@2038:
deba@2038: Item item;
deba@2038: int value;
deba@2038:
deba@2038: int prev, next;
deba@2038: };
deba@2038:
deba@2038: ItemIntMap& index;
deba@2038: std::vector<int> first;
deba@2038: std::vector<BucketItem> data;
deba@2038: mutable int maximal;
deba@2038:
deba@2038: }; // class BucketHeap
deba@2038:
deba@2089: /// \ingroup auxdat
deba@2089: ///
deba@2089: /// \brief A Simplified Bucket Heap implementation.
deba@2089: ///
deba@2089: /// This class implements a simplified \e bucket \e heap data
deba@2089: /// structure. It does not provide some functionality but it faster
deba@2089: /// and simplier data structure than the BucketHeap. The main
deba@2089: /// difference is that the BucketHeap stores for every key a double
deba@2089: /// linked list while this class stores just simple lists. In the
deba@2089: /// other way it does not supports erasing each elements just the
deba@2089: /// minimal and it does not supports key increasing, decreasing.
deba@2089: ///
deba@2089: /// \param _ItemIntMap A read and writable Item int map, used internally
deba@2089: /// to handle the cross references.
deba@2089: /// \param minimize If the given parameter is true then the heap gives back
deba@2089: /// the lowest priority.
deba@2089: ///
deba@2089: /// \sa BucketHeap
mqrelly@2263: template <typename _ItemIntMap, bool minimize = true >
deba@2089: class SimpleBucketHeap {
deba@2089:
deba@2089: public:
mqrelly@2263: typedef typename _ItemIntMap::Key Item;
deba@2089: typedef int Prio;
deba@2089: typedef std::pair<Item, Prio> Pair;
deba@2089: typedef _ItemIntMap ItemIntMap;
deba@2089:
deba@2089: /// \brief Type to represent the items states.
deba@2089: ///
deba@2089: /// Each Item element have a state associated to it. It may be "in heap",
deba@2089: /// "pre heap" or "post heap". The latter two are indifferent from the
deba@2089: /// heap's point of view, but may be useful to the user.
deba@2089: ///
deba@2089: /// The ItemIntMap \e should be initialized in such way that it maps
deba@2089: /// PRE_HEAP (-1) to any element to be put in the heap...
deba@2089: enum state_enum {
deba@2089: IN_HEAP = 0,
deba@2089: PRE_HEAP = -1,
deba@2089: POST_HEAP = -2
deba@2089: };
deba@2089:
deba@2089: public:
deba@2089:
deba@2089: /// \brief The constructor.
deba@2089: ///
deba@2089: /// The constructor.
deba@2089: /// \param _index should be given to the constructor, since it is used
deba@2089: /// internally to handle the cross references. The value of the map
deba@2089: /// should be PRE_HEAP (-1) for each element.
deba@2089: explicit SimpleBucketHeap(ItemIntMap &_index)
deba@2089: : index(_index), free(-1), num(0), minimal(0) {}
deba@2089:
deba@2089: /// \brief Returns the number of items stored in the heap.
deba@2089: ///
deba@2089: /// The number of items stored in the heap.
deba@2089: int size() const { return num; }
deba@2089:
deba@2089: /// \brief Checks if the heap stores no items.
deba@2089: ///
deba@2089: /// Returns \c true if and only if the heap stores no items.
deba@2089: bool empty() const { return num == 0; }
deba@2089:
deba@2089: /// \brief Make empty this heap.
deba@2089: ///
deba@2089: /// Make empty this heap. It does not change the cross reference
deba@2089: /// map. If you want to reuse a heap what is not surely empty you
deba@2089: /// should first clear the heap and after that you should set the
deba@2089: /// cross reference map for each item to \c PRE_HEAP.
deba@2089: void clear() {
deba@2089: data.clear(); first.clear(); free = -1; num = 0; minimal = 0;
deba@2089: }
deba@2089:
deba@2089: /// \brief Insert a pair of item and priority into the heap.
deba@2089: ///
deba@2089: /// Adds \c p.first to the heap with priority \c p.second.
deba@2089: /// \param p The pair to insert.
deba@2089: void push(const Pair& p) {
deba@2089: push(p.first, p.second);
deba@2089: }
deba@2089:
deba@2089: /// \brief Insert an item into the heap with the given priority.
deba@2089: ///
deba@2089: /// Adds \c i to the heap with priority \c p.
deba@2089: /// \param i The item to insert.
deba@2089: /// \param p The priority of the item.
deba@2089: void push(const Item &i, const Prio &p) {
deba@2089: int idx;
deba@2089: if (free == -1) {
deba@2089: idx = data.size();
deba@2110: data.push_back(BucketItem(i));
deba@2089: } else {
deba@2089: idx = free;
deba@2089: free = data[idx].next;
deba@2110: data[idx].item = i;
deba@2089: }
deba@2089: index[i] = idx;
deba@2089: if (p >= (int)first.size()) first.resize(p + 1, -1);
deba@2089: data[idx].next = first[p];
deba@2089: first[p] = idx;
deba@2089: if (p < minimal) {
deba@2089: minimal = p;
deba@2089: }
deba@2089: ++num;
deba@2089: }
deba@2089:
deba@2089: /// \brief Returns the item with minimum priority.
deba@2089: ///
deba@2089: /// This method returns the item with minimum priority.
deba@2089: /// \pre The heap must be nonempty.
deba@2089: Item top() const {
deba@2089: while (first[minimal] == -1) {
deba@2089: ++minimal;
deba@2089: }
deba@2089: return data[first[minimal]].item;
deba@2089: }
deba@2089:
deba@2089: /// \brief Returns the minimum priority.
deba@2089: ///
deba@2089: /// It returns the minimum priority.
deba@2089: /// \pre The heap must be nonempty.
deba@2089: Prio prio() const {
deba@2089: while (first[minimal] == -1) {
deba@2089: ++minimal;
deba@2089: }
deba@2089: return minimal;
deba@2089: }
deba@2089:
deba@2089: /// \brief Deletes the item with minimum priority.
deba@2089: ///
deba@2089: /// This method deletes the item with minimum priority from the heap.
deba@2089: /// \pre The heap must be non-empty.
deba@2089: void pop() {
deba@2089: while (first[minimal] == -1) {
deba@2089: ++minimal;
deba@2089: }
deba@2089: int idx = first[minimal];
deba@2089: index[data[idx].item] = -2;
deba@2089: first[minimal] = data[idx].next;
deba@2089: data[idx].next = free;
deba@2089: free = idx;
deba@2089: --num;
deba@2089: }
deba@2089:
deba@2089: /// \brief Returns the priority of \c i.
deba@2089: ///
deba@2110: /// This function returns the priority of item \c i.
deba@2110: /// \warning This operator is not a constant time function
deba@2110: /// because it scans the whole data structure to find the proper
deba@2110: /// value.
deba@2089: /// \pre \c i must be in the heap.
deba@2089: /// \param i The item.
deba@2089: Prio operator[](const Item &i) const {
deba@2110: for (int k = 0; k < first.size(); ++k) {
deba@2110: int idx = first[k];
deba@2110: while (idx != -1) {
deba@2110: if (data[idx].item == i) {
deba@2110: return k;
deba@2110: }
deba@2110: idx = data[idx].next;
deba@2110: }
deba@2110: }
deba@2110: return -1;
deba@2089: }
deba@2089:
deba@2089: /// \brief Returns if \c item is in, has already been in, or has
deba@2089: /// never been in the heap.
deba@2089: ///
deba@2089: /// This method returns PRE_HEAP if \c item has never been in the
deba@2089: /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
deba@2089: /// otherwise. In the latter case it is possible that \c item will
deba@2089: /// get back to the heap again.
deba@2089: /// \param i The item.
deba@2089: state_enum state(const Item &i) const {
deba@2089: int idx = index[i];
deba@2089: if (idx >= 0) idx = 0;
deba@2089: return state_enum(idx);
deba@2089: }
deba@2089:
deba@2089: private:
deba@2089:
deba@2089: struct BucketItem {
deba@2110: BucketItem(const Item& _item)
deba@2110: : item(_item) {}
deba@2089:
deba@2089: Item item;
deba@2089: int next;
deba@2089: };
deba@2089:
deba@2089: ItemIntMap& index;
deba@2089: std::vector<int> first;
deba@2089: std::vector<BucketItem> data;
deba@2089: int free, num;
deba@2089: mutable int minimal;
deba@2089:
deba@2089: }; // class SimpleBucketHeap
deba@2089:
mqrelly@2263: template <typename _ItemIntMap>
mqrelly@2263: class SimpleBucketHeap<_ItemIntMap, false> {
deba@2089:
deba@2089: public:
mqrelly@2263: typedef typename _ItemIntMap::Key Item;
deba@2089: typedef int Prio;
deba@2089: typedef std::pair<Item, Prio> Pair;
deba@2089: typedef _ItemIntMap ItemIntMap;
deba@2089:
deba@2089: enum state_enum {
deba@2089: IN_HEAP = 0,
deba@2089: PRE_HEAP = -1,
deba@2089: POST_HEAP = -2
deba@2089: };
deba@2089:
deba@2089: public:
deba@2089:
deba@2089: explicit SimpleBucketHeap(ItemIntMap &_index)
deba@2089: : index(_index), free(-1), num(0), maximal(0) {}
deba@2089:
deba@2089: int size() const { return num; }
deba@2089:
deba@2089: bool empty() const { return num == 0; }
deba@2089:
deba@2089: void clear() {
deba@2089: data.clear(); first.clear(); free = -1; num = 0; maximal = 0;
deba@2089: }
deba@2089:
deba@2089: void push(const Pair& p) {
deba@2089: push(p.first, p.second);
deba@2089: }
deba@2089:
deba@2089: void push(const Item &i, const Prio &p) {
deba@2089: int idx;
deba@2089: if (free == -1) {
deba@2089: idx = data.size();
deba@2110: data.push_back(BucketItem(i));
deba@2089: } else {
deba@2089: idx = free;
deba@2089: free = data[idx].next;
deba@2110: data[idx].item = i;
deba@2089: }
deba@2089: index[i] = idx;
deba@2089: if (p >= (int)first.size()) first.resize(p + 1, -1);
deba@2089: data[idx].next = first[p];
deba@2089: first[p] = idx;
deba@2089: if (p > maximal) {
deba@2089: maximal = p;
deba@2089: }
deba@2089: ++num;
deba@2089: }
deba@2089:
deba@2089: Item top() const {
deba@2089: while (first[maximal] == -1) {
deba@2089: --maximal;
deba@2089: }
deba@2089: return data[first[maximal]].item;
deba@2089: }
deba@2089:
deba@2089: Prio prio() const {
deba@2089: while (first[maximal] == -1) {
deba@2089: --maximal;
deba@2089: }
deba@2089: return maximal;
deba@2089: }
deba@2089:
deba@2089: void pop() {
deba@2089: while (first[maximal] == -1) {
deba@2089: --maximal;
deba@2089: }
deba@2089: int idx = first[maximal];
deba@2089: index[data[idx].item] = -2;
deba@2089: first[maximal] = data[idx].next;
deba@2089: data[idx].next = free;
deba@2089: free = idx;
deba@2089: --num;
deba@2089: }
deba@2089:
deba@2089: Prio operator[](const Item &i) const {
deba@2110: for (int k = 0; k < first.size(); ++k) {
deba@2110: int idx = first[k];
deba@2110: while (idx != -1) {
deba@2110: if (data[idx].item == i) {
deba@2110: return k;
deba@2110: }
deba@2110: idx = data[idx].next;
deba@2110: }
deba@2110: }
deba@2110: return -1;
deba@2089: }
deba@2089:
deba@2089: state_enum state(const Item &i) const {
deba@2089: int idx = index[i];
deba@2089: if (idx >= 0) idx = 0;
deba@2089: return state_enum(idx);
deba@2089: }
deba@2089:
deba@2089: private:
deba@2089:
deba@2089: struct BucketItem {
deba@2110: BucketItem(const Item& _item) : item(_item) {}
deba@2089:
deba@2089: Item item;
deba@2089:
deba@2089: int next;
deba@2089: };
deba@2089:
deba@2089: ItemIntMap& index;
deba@2089: std::vector<int> first;
deba@2089: std::vector<BucketItem> data;
deba@2089: int free, num;
deba@2089: mutable int maximal;
deba@2089:
deba@2089: };
deba@2089:
deba@2038: }
deba@2038:
deba@2038: #endif