dust3d/thirdparty/QuadriFlow/3rd/lemon-1.3.1/lemon/max_cardinality_search.h

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/* -*- mode: C++; indent-tabs-mode: nil; -*-
*
* This file is a part of LEMON, a generic C++ optimization library.
*
* Copyright (C) 2003-2013
* Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
* (Egervary Research Group on Combinatorial Optimization, EGRES).
*
* Permission to use, modify and distribute this software is granted
* provided that this copyright notice appears in all copies. For
* precise terms see the accompanying LICENSE file.
*
* This software is provided "AS IS" with no warranty of any kind,
* express or implied, and with no claim as to its suitability for any
* purpose.
*
*/
#ifndef LEMON_MAX_CARDINALITY_SEARCH_H
#define LEMON_MAX_CARDINALITY_SEARCH_H
/// \ingroup search
/// \file
/// \brief Maximum cardinality search in undirected digraphs.
#include <lemon/bin_heap.h>
#include <lemon/bucket_heap.h>
#include <lemon/error.h>
#include <lemon/maps.h>
#include <functional>
namespace lemon {
/// \brief Default traits class of MaxCardinalitySearch class.
///
/// Default traits class of MaxCardinalitySearch class.
/// \param Digraph Digraph type.
/// \param CapacityMap Type of capacity map.
template <typename GR, typename CAP>
struct MaxCardinalitySearchDefaultTraits {
/// The digraph type the algorithm runs on.
typedef GR Digraph;
template <typename CM>
struct CapMapSelector {
typedef CM CapacityMap;
static CapacityMap *createCapacityMap(const Digraph& g) {
return new CapacityMap(g);
}
};
template <typename CM>
struct CapMapSelector<ConstMap<CM, Const<int, 1> > > {
typedef ConstMap<CM, Const<int, 1> > CapacityMap;
static CapacityMap *createCapacityMap(const Digraph&) {
return new CapacityMap;
}
};
/// \brief The type of the map that stores the arc capacities.
///
/// The type of the map that stores the arc capacities.
/// It must meet the \ref concepts::ReadMap "ReadMap" concept.
typedef typename CapMapSelector<CAP>::CapacityMap CapacityMap;
/// \brief The type of the capacity of the arcs.
typedef typename CapacityMap::Value Value;
/// \brief Instantiates a CapacityMap.
///
/// This function instantiates a \ref CapacityMap.
/// \param digraph is the digraph, to which we would like to define
/// the CapacityMap.
static CapacityMap *createCapacityMap(const Digraph& digraph) {
return CapMapSelector<CapacityMap>::createCapacityMap(digraph);
}
/// \brief The cross reference type used by heap.
///
/// The cross reference type used by heap.
/// Usually it is \c Digraph::NodeMap<int>.
typedef typename Digraph::template NodeMap<int> HeapCrossRef;
/// \brief Instantiates a HeapCrossRef.
///
/// This function instantiates a \ref HeapCrossRef.
/// \param digraph is the digraph, to which we would like to define the
/// HeapCrossRef.
static HeapCrossRef *createHeapCrossRef(const Digraph &digraph) {
return new HeapCrossRef(digraph);
}
template <typename CapacityMap>
struct HeapSelector {
template <typename Value, typename Ref>
struct Selector {
typedef BinHeap<Value, Ref, std::greater<Value> > Heap;
};
};
template <typename CapacityKey>
struct HeapSelector<ConstMap<CapacityKey, Const<int, 1> > > {
template <typename Value, typename Ref>
struct Selector {
typedef BucketHeap<Ref, false > Heap;
};
};
/// \brief The heap type used by MaxCardinalitySearch algorithm.
///
/// The heap type used by MaxCardinalitySearch algorithm. It should
/// maximalize the priorities. The default heap type is
/// the \ref BinHeap, but it is specialized when the
/// CapacityMap is ConstMap<Digraph::Node, Const<int, 1> >
/// to BucketHeap.
///
/// \sa MaxCardinalitySearch
typedef typename HeapSelector<CapacityMap>
::template Selector<Value, HeapCrossRef>
::Heap Heap;
/// \brief Instantiates a Heap.
///
/// This function instantiates a \ref Heap.
/// \param crossref The cross reference of the heap.
static Heap *createHeap(HeapCrossRef& crossref) {
return new Heap(crossref);
}
/// \brief The type of the map that stores whether a node is processed.
///
/// The type of the map that stores whether a node is processed.
/// It must meet the \ref concepts::WriteMap "WriteMap" concept.
/// By default it is a NullMap.
typedef NullMap<typename Digraph::Node, bool> ProcessedMap;
/// \brief Instantiates a ProcessedMap.
///
/// This function instantiates a \ref ProcessedMap.
/// \param digraph is the digraph, to which
/// we would like to define the \ref ProcessedMap
#ifdef DOXYGEN
static ProcessedMap *createProcessedMap(const Digraph &digraph)
#else
static ProcessedMap *createProcessedMap(const Digraph &)
#endif
{
return new ProcessedMap();
}
/// \brief The type of the map that stores the cardinalities of the nodes.
///
/// The type of the map that stores the cardinalities of the nodes.
/// It must meet the \ref concepts::WriteMap "WriteMap" concept.
typedef typename Digraph::template NodeMap<Value> CardinalityMap;
/// \brief Instantiates a CardinalityMap.
///
/// This function instantiates a \ref CardinalityMap.
/// \param digraph is the digraph, to which we would like to
/// define the \ref CardinalityMap
static CardinalityMap *createCardinalityMap(const Digraph &digraph) {
return new CardinalityMap(digraph);
}
};
/// \ingroup search
///
/// \brief Maximum Cardinality Search algorithm class.
///
/// This class provides an efficient implementation of Maximum Cardinality
/// Search algorithm. The maximum cardinality search first chooses any
/// node of the digraph. Then every time it chooses one unprocessed node
/// with maximum cardinality, i.e the sum of capacities on out arcs
/// to the nodes
/// which were previusly processed.
/// If there is a cut in the digraph the algorithm should choose
/// again any unprocessed node of the digraph.
/// The arc capacities are passed to the algorithm using a
/// \ref concepts::ReadMap "ReadMap", so it is easy to change it to any
/// kind of capacity.
///
/// The type of the capacity is determined by the \ref
/// concepts::ReadMap::Value "Value" of the capacity map.
///
/// It is also possible to change the underlying priority heap.
///
///
/// \param GR The digraph type the algorithm runs on. The value of
/// Digraph is not used directly by the search algorithm, it
/// is only passed to \ref MaxCardinalitySearchDefaultTraits.
/// \param CAP This read-only ArcMap determines the capacities of
/// the arcs. It is read once for each arc, so the map may involve in
/// relatively time consuming process to compute the arc capacity if
/// it is necessary. The default map type is \ref
/// ConstMap "ConstMap<concepts::Digraph::Arc, Const<int,1> >". The value
/// of CapacityMap is not used directly by search algorithm, it is only
/// passed to \ref MaxCardinalitySearchDefaultTraits.
/// \param TR Traits class to set various data types used by the
/// algorithm. The default traits class is
/// \ref MaxCardinalitySearchDefaultTraits
/// "MaxCardinalitySearchDefaultTraits<GR, CAP>".
/// See \ref MaxCardinalitySearchDefaultTraits
/// for the documentation of a MaxCardinalitySearch traits class.
#ifdef DOXYGEN
template <typename GR, typename CAP, typename TR>
#else
template <typename GR, typename CAP =
ConstMap<typename GR::Arc, Const<int,1> >,
typename TR =
MaxCardinalitySearchDefaultTraits<GR, CAP> >
#endif
class MaxCardinalitySearch {
public:
typedef TR Traits;
///The type of the underlying digraph.
typedef typename Traits::Digraph Digraph;
///The type of the capacity of the arcs.
typedef typename Traits::CapacityMap::Value Value;
///The type of the map that stores the arc capacities.
typedef typename Traits::CapacityMap CapacityMap;
///The type of the map indicating if a node is processed.
typedef typename Traits::ProcessedMap ProcessedMap;
///The type of the map that stores the cardinalities of the nodes.
typedef typename Traits::CardinalityMap CardinalityMap;
///The cross reference type used for the current heap.
typedef typename Traits::HeapCrossRef HeapCrossRef;
///The heap type used by the algorithm. It maximizes the priorities.
typedef typename Traits::Heap Heap;
private:
// Pointer to the underlying digraph.
const Digraph *_graph;
// Pointer to the capacity map
const CapacityMap *_capacity;
// Indicates if \ref _capacity is locally allocated (\c true) or not.
bool local_capacity;
// Pointer to the map of cardinality.
CardinalityMap *_cardinality;
// Indicates if \ref _cardinality is locally allocated (\c true) or not.
bool local_cardinality;
// Pointer to the map of processed status of the nodes.
ProcessedMap *_processed;
// Indicates if \ref _processed is locally allocated (\c true) or not.
bool local_processed;
// Pointer to the heap cross references.
HeapCrossRef *_heap_cross_ref;
// Indicates if \ref _heap_cross_ref is locally allocated (\c true) or not.
bool local_heap_cross_ref;
// Pointer to the heap.
Heap *_heap;
// Indicates if \ref _heap is locally allocated (\c true) or not.
bool local_heap;
public :
typedef MaxCardinalitySearch Create;
///\name Named template parameters
///@{
template <class T>
struct DefCapacityMapTraits : public Traits {
typedef T CapacityMap;
static CapacityMap *createCapacityMap(const Digraph &) {
LEMON_ASSERT(false,"Uninitialized parameter.");
return 0;
}
};
/// \brief \ref named-templ-param "Named parameter" for setting
/// CapacityMap type
///
/// \ref named-templ-param "Named parameter" for setting CapacityMap type
/// for the algorithm.
template <class T>
struct SetCapacityMap
: public MaxCardinalitySearch<Digraph, CapacityMap,
DefCapacityMapTraits<T> > {
typedef MaxCardinalitySearch<Digraph, CapacityMap,
DefCapacityMapTraits<T> > Create;
};
template <class T>
struct DefCardinalityMapTraits : public Traits {
typedef T CardinalityMap;
static CardinalityMap *createCardinalityMap(const Digraph &)
{
LEMON_ASSERT(false,"Uninitialized parameter.");
return 0;
}
};
/// \brief \ref named-templ-param "Named parameter" for setting
/// CardinalityMap type
///
/// \ref named-templ-param "Named parameter" for setting CardinalityMap
/// type for the algorithm.
template <class T>
struct SetCardinalityMap
: public MaxCardinalitySearch<Digraph, CapacityMap,
DefCardinalityMapTraits<T> > {
typedef MaxCardinalitySearch<Digraph, CapacityMap,
DefCardinalityMapTraits<T> > Create;
};
template <class T>
struct DefProcessedMapTraits : public Traits {
typedef T ProcessedMap;
static ProcessedMap *createProcessedMap(const Digraph &) {
LEMON_ASSERT(false,"Uninitialized parameter.");
return 0;
}
};
/// \brief \ref named-templ-param "Named parameter" for setting
/// ProcessedMap type
///
/// \ref named-templ-param "Named parameter" for setting ProcessedMap type
/// for the algorithm.
template <class T>
struct SetProcessedMap
: public MaxCardinalitySearch<Digraph, CapacityMap,
DefProcessedMapTraits<T> > {
typedef MaxCardinalitySearch<Digraph, CapacityMap,
DefProcessedMapTraits<T> > Create;
};
template <class H, class CR>
struct DefHeapTraits : public Traits {
typedef CR HeapCrossRef;
typedef H Heap;
static HeapCrossRef *createHeapCrossRef(const Digraph &) {
LEMON_ASSERT(false,"Uninitialized parameter.");
return 0;
}
static Heap *createHeap(HeapCrossRef &) {
LEMON_ASSERT(false,"Uninitialized parameter.");
return 0;
}
};
/// \brief \ref named-templ-param "Named parameter" for setting heap
/// and cross reference type
///
/// \ref named-templ-param "Named parameter" for setting heap and cross
/// reference type for the algorithm.
template <class H, class CR = typename Digraph::template NodeMap<int> >
struct SetHeap
: public MaxCardinalitySearch<Digraph, CapacityMap,
DefHeapTraits<H, CR> > {
typedef MaxCardinalitySearch< Digraph, CapacityMap,
DefHeapTraits<H, CR> > Create;
};
template <class H, class CR>
struct DefStandardHeapTraits : public Traits {
typedef CR HeapCrossRef;
typedef H Heap;
static HeapCrossRef *createHeapCrossRef(const Digraph &digraph) {
return new HeapCrossRef(digraph);
}
static Heap *createHeap(HeapCrossRef &crossref) {
return new Heap(crossref);
}
};
/// \brief \ref named-templ-param "Named parameter" for setting heap and
/// cross reference type with automatic allocation
///
/// \ref named-templ-param "Named parameter" for setting heap and cross
/// reference type. It can allocate the heap and the cross reference
/// object if the cross reference's constructor waits for the digraph as
/// parameter and the heap's constructor waits for the cross reference.
template <class H, class CR = typename Digraph::template NodeMap<int> >
struct SetStandardHeap
: public MaxCardinalitySearch<Digraph, CapacityMap,
DefStandardHeapTraits<H, CR> > {
typedef MaxCardinalitySearch<Digraph, CapacityMap,
DefStandardHeapTraits<H, CR> >
Create;
};
///@}
protected:
MaxCardinalitySearch() {}
public:
/// \brief Constructor.
///
///\param digraph the digraph the algorithm will run on.
///\param capacity the capacity map used by the algorithm.
MaxCardinalitySearch(const Digraph& digraph,
const CapacityMap& capacity) :
_graph(&digraph),
_capacity(&capacity), local_capacity(false),
_cardinality(0), local_cardinality(false),
_processed(0), local_processed(false),
_heap_cross_ref(0), local_heap_cross_ref(false),
_heap(0), local_heap(false)
{ }
/// \brief Constructor.
///
///\param digraph the digraph the algorithm will run on.
///
///A constant 1 capacity map will be allocated.
MaxCardinalitySearch(const Digraph& digraph) :
_graph(&digraph),
_capacity(0), local_capacity(false),
_cardinality(0), local_cardinality(false),
_processed(0), local_processed(false),
_heap_cross_ref(0), local_heap_cross_ref(false),
_heap(0), local_heap(false)
{ }
/// \brief Destructor.
~MaxCardinalitySearch() {
if(local_capacity) delete _capacity;
if(local_cardinality) delete _cardinality;
if(local_processed) delete _processed;
if(local_heap_cross_ref) delete _heap_cross_ref;
if(local_heap) delete _heap;
}
/// \brief Sets the capacity map.
///
/// Sets the capacity map.
/// \return <tt> (*this) </tt>
MaxCardinalitySearch &capacityMap(const CapacityMap &m) {
if (local_capacity) {
delete _capacity;
local_capacity=false;
}
_capacity=&m;
return *this;
}
/// \brief Returns a const reference to the capacity map.
///
/// Returns a const reference to the capacity map used by
/// the algorithm.
const CapacityMap &capacityMap() const {
return *_capacity;
}
/// \brief Sets the map storing the cardinalities calculated by the
/// algorithm.
///
/// Sets the map storing the cardinalities calculated by the algorithm.
/// If you don't use this function before calling \ref run(),
/// it will allocate one. The destuctor deallocates this
/// automatically allocated map, of course.
/// \return <tt> (*this) </tt>
MaxCardinalitySearch &cardinalityMap(CardinalityMap &m) {
if(local_cardinality) {
delete _cardinality;
local_cardinality=false;
}
_cardinality = &m;
return *this;
}
/// \brief Sets the map storing the processed nodes.
///
/// Sets the map storing the processed nodes.
/// If you don't use this function before calling \ref run(),
/// it will allocate one. The destuctor deallocates this
/// automatically allocated map, of course.
/// \return <tt> (*this) </tt>
MaxCardinalitySearch &processedMap(ProcessedMap &m)
{
if(local_processed) {
delete _processed;
local_processed=false;
}
_processed = &m;
return *this;
}
/// \brief Returns a const reference to the cardinality map.
///
/// Returns a const reference to the cardinality map used by
/// the algorithm.
const ProcessedMap &processedMap() const {
return *_processed;
}
/// \brief Sets the heap and the cross reference used by algorithm.
///
/// Sets the heap and the cross reference used by algorithm.
/// If you don't use this function before calling \ref run(),
/// it will allocate one. The destuctor deallocates this
/// automatically allocated map, of course.
/// \return <tt> (*this) </tt>
MaxCardinalitySearch &heap(Heap& hp, HeapCrossRef &cr) {
if(local_heap_cross_ref) {
delete _heap_cross_ref;
local_heap_cross_ref = false;
}
_heap_cross_ref = &cr;
if(local_heap) {
delete _heap;
local_heap = false;
}
_heap = &hp;
return *this;
}
/// \brief Returns a const reference to the heap.
///
/// Returns a const reference to the heap used by
/// the algorithm.
const Heap &heap() const {
return *_heap;
}
/// \brief Returns a const reference to the cross reference.
///
/// Returns a const reference to the cross reference
/// of the heap.
const HeapCrossRef &heapCrossRef() const {
return *_heap_cross_ref;
}
private:
typedef typename Digraph::Node Node;
typedef typename Digraph::NodeIt NodeIt;
typedef typename Digraph::Arc Arc;
typedef typename Digraph::InArcIt InArcIt;
void create_maps() {
if(!_capacity) {
local_capacity = true;
_capacity = Traits::createCapacityMap(*_graph);
}
if(!_cardinality) {
local_cardinality = true;
_cardinality = Traits::createCardinalityMap(*_graph);
}
if(!_processed) {
local_processed = true;
_processed = Traits::createProcessedMap(*_graph);
}
if (!_heap_cross_ref) {
local_heap_cross_ref = true;
_heap_cross_ref = Traits::createHeapCrossRef(*_graph);
}
if (!_heap) {
local_heap = true;
_heap = Traits::createHeap(*_heap_cross_ref);
}
}
void finalizeNodeData(Node node, Value capacity) {
_processed->set(node, true);
_cardinality->set(node, capacity);
}
public:
/// \name Execution control
/// The simplest way to execute the algorithm is to use
/// one of the member functions called \ref run().
/// \n
/// If you need more control on the execution,
/// first you must call \ref init(), then you can add several source nodes
/// with \ref addSource().
/// Finally \ref start() will perform the computation.
///@{
/// \brief Initializes the internal data structures.
///
/// Initializes the internal data structures, and clears the heap.
void init() {
create_maps();
_heap->clear();
for (NodeIt it(*_graph) ; it != INVALID ; ++it) {
_processed->set(it, false);
_heap_cross_ref->set(it, Heap::PRE_HEAP);
}
}
/// \brief Adds a new source node.
///
/// Adds a new source node to the priority heap.
///
/// It checks if the node has not yet been added to the heap.
void addSource(Node source, Value capacity = 0) {
if(_heap->state(source) == Heap::PRE_HEAP) {
_heap->push(source, capacity);
}
}
/// \brief Processes the next node in the priority heap
///
/// Processes the next node in the priority heap.
///
/// \return The processed node.
///
/// \warning The priority heap must not be empty!
Node processNextNode() {
Node node = _heap->top();
finalizeNodeData(node, _heap->prio());
_heap->pop();
for (InArcIt it(*_graph, node); it != INVALID; ++it) {
Node source = _graph->source(it);
switch (_heap->state(source)) {
case Heap::PRE_HEAP:
_heap->push(source, (*_capacity)[it]);
break;
case Heap::IN_HEAP:
_heap->decrease(source, (*_heap)[source] + (*_capacity)[it]);
break;
case Heap::POST_HEAP:
break;
}
}
return node;
}
/// \brief Next node to be processed.
///
/// Next node to be processed.
///
/// \return The next node to be processed or INVALID if the
/// priority heap is empty.
Node nextNode() {
return !_heap->empty() ? _heap->top() : INVALID;
}
/// \brief Returns \c false if there are nodes
/// to be processed in the priority heap
///
/// Returns \c false if there are nodes
/// to be processed in the priority heap
bool emptyQueue() { return _heap->empty(); }
/// \brief Returns the number of the nodes to be processed
/// in the priority heap
///
/// Returns the number of the nodes to be processed in the priority heap
int emptySize() { return _heap->size(); }
/// \brief Executes the algorithm.
///
/// Executes the algorithm.
///
///\pre init() must be called and at least one node should be added
/// with addSource() before using this function.
///
/// This method runs the Maximum Cardinality Search algorithm from the
/// source node(s).
void start() {
while ( !_heap->empty() ) processNextNode();
}
/// \brief Executes the algorithm until \c dest is reached.
///
/// Executes the algorithm until \c dest is reached.
///
/// \pre init() must be called and at least one node should be added
/// with addSource() before using this function.
///
/// This method runs the %MaxCardinalitySearch algorithm from the source
/// nodes.
void start(Node dest) {
while ( !_heap->empty() && _heap->top()!=dest ) processNextNode();
if ( !_heap->empty() ) finalizeNodeData(_heap->top(), _heap->prio());
}
/// \brief Executes the algorithm until a condition is met.
///
/// Executes the algorithm until a condition is met.
///
/// \pre init() must be called and at least one node should be added
/// with addSource() before using this function.
///
/// \param nm must be a bool (or convertible) node map. The algorithm
/// will stop when it reaches a node \c v with <tt>nm[v]==true</tt>.
template <typename NodeBoolMap>
void start(const NodeBoolMap &nm) {
while ( !_heap->empty() && !nm[_heap->top()] ) processNextNode();
if ( !_heap->empty() ) finalizeNodeData(_heap->top(),_heap->prio());
}
/// \brief Runs the maximum cardinality search algorithm from node \c s.
///
/// This method runs the %MaxCardinalitySearch algorithm from a root
/// node \c s.
///
///\note d.run(s) is just a shortcut of the following code.
///\code
/// d.init();
/// d.addSource(s);
/// d.start();
///\endcode
void run(Node s) {
init();
addSource(s);
start();
}
/// \brief Runs the maximum cardinality search algorithm for the
/// whole digraph.
///
/// This method runs the %MaxCardinalitySearch algorithm from all
/// unprocessed node of the digraph.
///
///\note d.run(s) is just a shortcut of the following code.
///\code
/// d.init();
/// for (NodeIt it(digraph); it != INVALID; ++it) {
/// if (!d.reached(it)) {
/// d.addSource(s);
/// d.start();
/// }
/// }
///\endcode
void run() {
init();
for (NodeIt it(*_graph); it != INVALID; ++it) {
if (!reached(it)) {
addSource(it);
start();
}
}
}
///@}
/// \name Query Functions
/// The results of the maximum cardinality search algorithm can be
/// obtained using these functions.
/// \n
/// Before the use of these functions, either run() or start() must be
/// called.
///@{
/// \brief The cardinality of a node.
///
/// Returns the cardinality of a node.
/// \pre \ref run() must be called before using this function.
/// \warning If node \c v in unreachable from the root the return value
/// of this funcion is undefined.
Value cardinality(Node node) const { return (*_cardinality)[node]; }
/// \brief The current cardinality of a node.
///
/// Returns the current cardinality of a node.
/// \pre the given node should be reached but not processed
Value currentCardinality(Node node) const { return (*_heap)[node]; }
/// \brief Returns a reference to the NodeMap of cardinalities.
///
/// Returns a reference to the NodeMap of cardinalities. \pre \ref run()
/// must be called before using this function.
const CardinalityMap &cardinalityMap() const { return *_cardinality;}
/// \brief Checks if a node is reachable from the root.
///
/// Returns \c true if \c v is reachable from the root.
/// \warning The source nodes are initated as unreached.
/// \pre \ref run() must be called before using this function.
bool reached(Node v) { return (*_heap_cross_ref)[v] != Heap::PRE_HEAP; }
/// \brief Checks if a node is processed.
///
/// Returns \c true if \c v is processed, i.e. the shortest
/// path to \c v has already found.
/// \pre \ref run() must be called before using this function.
bool processed(Node v) { return (*_heap_cross_ref)[v] == Heap::POST_HEAP; }
///@}
};
}
#endif