libsemigroups
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Class for partitioned binary relations (PBR). More...
#include <elements.h>
Public Member Functions | |
size_t | complexity () const override |
Returns the approximate time complexity of multiplying PBRs. More... | |
size_t | degree () const override |
Returns the degree of a PBR. More... | |
Element * | identity () const override |
Returns the identity PBR with degree equal to that of this . More... | |
void | redefine (Element const *x, Element const *y, size_t const &thread_id) override |
Multiply x and y and stores the result in this . More... | |
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ElementWithVectorData () | |
A constructor. More... | |
ElementWithVectorData (std::vector< std::vector< u_int32_t > > *vector) | |
A constructor. More... | |
ElementWithVectorData (std::vector< std::vector< u_int32_t > > const &vector) | |
A constructor. More... | |
std::vector< u_int32_t > | at (size_t pos) const |
Returns the pos entry in the vector containing the defining data. More... | |
std::vector< std::vector< u_int32_t > >::iterator | begin () const |
Returns an iterator. More... | |
std::vector< std::vector< u_int32_t > >::iterator | cbegin () const |
Returns a const iterator. More... | |
std::vector< std::vector< u_int32_t > >::iterator | cend () const |
Returns a const iterator. More... | |
void | copy (Element const *x) override |
Copy another Element into this . More... | |
std::vector< std::vector< u_int32_t > >::iterator | end () const |
Returns an iterator. More... | |
bool | operator< (Element const &that) const override |
Returns true if this is less than that . More... | |
bool | operator== (Element const &that) const override |
Returns true if this equals that . More... | |
std::vector< u_int32_t > | operator[] (size_t pos) const |
Returns the pos entry in the vector containing the defining data. More... | |
Element * | really_copy (size_t increase_deg_by=0) const override |
Returns a pointer to a copy of this . More... | |
void | really_delete () override |
Deletes the defining data of an ElementWithVectorData. More... | |
void | swap (Element *x) override |
Swap another Element with this . More... | |
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Element (elm_t type=Element::elm_t::NOT_RWSE) | |
A constructor. More... | |
virtual | ~Element () |
A default destructor. More... | |
elm_t | get_type () const |
Returns the type libsemigroups::Element::elm_t of an Element object. More... | |
size_t | hash_value () const |
Return the hash value of an Element. More... | |
virtual void | redefine (Element const *x, Element const *y) |
Multiplies x and y and stores the result in this . More... | |
Protected Member Functions | |
void | cache_hash_value () const override |
Calculate and cache a hash value. More... | |
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void | reset_hash_value () const |
Reset the cached value used by Element::hash_value. More... | |
Additional Inherited Members | |
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enum | elm_t { RWSE = 0, NOT_RWSE = 1 } |
This enum contains some different types of Element. More... | |
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static size_t | vector_hash (std::vector< T > const *vec) |
Returns a hash value for a vector provided there is a specialization of std::hash for the template type T . More... | |
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std::vector< std::vector< u_int32_t > > * | _vector |
The vector containing the defining data of this . More... | |
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static size_t const | UNDEFINED = std::numeric_limits<size_t>::max() |
UNDEFINED value. More... | |
Class for partitioned binary relations (PBR).
Partitioned binary relations (PBRs) are a generalisation of bipartitions, which were introduced by Martin and Mazorchuk.
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overrideprotectedvirtual |
Calculate and cache a hash value.
This method is used to compute and cache the hash value of this
.
Implements libsemigroups::Element.
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overridevirtual |
Returns the approximate time complexity of multiplying PBRs.
The approximate time complexity of multiplying PBRs is \(2n ^ 3\) where \(n\) is the degree.
Implements libsemigroups::Element.
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overridevirtual |
Returns the degree of a PBR.
The degree of a PBR is half the number of points in the PBR, which is also half the length of the underlying vector ElementWithVectorData::_vector.
Implements libsemigroups::Element.
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overridevirtual |
Returns the identity PBR with degree equal to that of this
.
This method returns a new PBR with degree equal to the degree of this
where every value is adjacent to its negative. Equivalently, \(i\) is adjacent \(i + n\) and vice versa for every \(i\) less than the degree \(n\).
Implements libsemigroups::Element.
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overridevirtual |
Multiply x
and y
and stores the result in this
.
This method redefines this
to be the product of the parameters x
and y
. This method asserts that the degrees of x
, y
, and this
, are all equal, and that neither x
nor y
equals this
.
The parameter thread_id
is required since some temporary storage is required to find the product of x
and y
. Note that if different threads call this method with the same value of thread_id
then bad things will happen.
Reimplemented from libsemigroups::Element.