Prefixes and suffixes¶
This page contains information about the member functions of the FroidurePinBase
class related to prefixes and suffixes.
-
inline letter_type libsemigroups::FroidurePinBase::final_letter(element_index_type pos) const¶
Returns the last letter of the element with specified index.
This function returns the final letter of the element in position
pos
of the semigroup, which is the index of the generator corresponding to the final letter of the element.- Complexity
Constant.
Note
Note that
FroidurePin::generator(first_letter(pos))
is only equal toFroidurePin::at(first_letter(pos))
if there are no duplicate generators.- Parameters
pos – the position
- Throws
LibsemigroupsException – if
pos
is greater than or equal to current_size.- Returns
A value of type
letter_type
.
-
inline letter_type libsemigroups::FroidurePinBase::first_letter(element_index_type pos) const¶
Returns the first letter of the element with specified index.
This function returns the first letter of the element in position
pos
of the semigroup, which is the index of the generator corresponding to the first letter of the element.- Complexity
Constant.
Note
Note that
FroidurePin::generator(first_letter(pos))
is only equal toFroidurePin::at(first_letter(pos))
if there are no duplicate generators.- Parameters
pos – the position
- Throws
LibsemigroupsException – if
pos
is greater than or equal to current_size.- Returns
A value of type
letter_type
.
-
inline element_index_type libsemigroups::FroidurePinBase::prefix(element_index_type pos) const¶
Returns the position of the longest proper prefix.
Returns the position of the prefix of the element
x
in positionpos
(of the semigroup) of length one less than the length ofx
.- Complexity
Constant.
- Parameters
pos – the position
- Throws
LibsemigroupsException – if
pos
is greater than or equal to current_size.- Returns
A value of type
element_index_type
.
-
inline element_index_type libsemigroups::FroidurePinBase::suffix(element_index_type pos) const¶
Returns the position of the longest proper suffix.
Returns the position of the suffix of the element
x
in positionpos
(of the semigroup) of length one less than the length ofx
.- Complexity
Constant.
- Parameters
pos – the position
- Throws
LibsemigroupsException – if
pos
is greater than or equal to current_size.- Returns
A value of type
element_index_type
.