cbegin_panilo¶
-
const_panilo_iterator
libsemigroups::ActionDigraph
::
cbegin_panilo
(node_type const source, size_t const min = 0, size_t const max = POSITIVE_INFINITY) const¶ Returns a forward iterator pointing to a pair consisting of the edge labels of the first path (in lexicographical order) starting at
source
with length in the range \([min, max)\) and the last node of that path.PANILO = Path And Node In Lexicographical Order
If incremented, the iterator will point to the next least edge labelling of a path (in lexicographical order), and its last node, with length in the range \([min, max)\). Iterators of the type returned by this function are equal whenever they point to equal objects.
- Return
An iterator
it
of typeconst_panilo_iterator
pointing to a std::pair where:it->first
is a libsemigroups::word_type consisting of the edge labels of the first path (in lexicographical order) fromsource
of length in the range \([min, max)\); andit->second
is the last node on the path fromsource
labelled byit->first
, a value of ActionDigraph::node_type.
- Warning
Copying iterators of this type is expensive. As a consequence, prefix incrementing
++it
the returned iteratorit
significantly cheaper than postfix incrementingit++
.- Warning
If the action digraph represented by
this
contains a cycle that is reachable fromsource
, then there are infinitely many paths starting atsource
, and somax
should be chosen with some care.- See
- Parameters
source
: the source nodemin
: the minimum length of a path to enumerate (defaults to0
)max
: the maximum length of a path to enumerate (defaults to libsemigroups::POSITIVE_INFINITY).
- Exceptions
LibsemigroupsException
: ifsource
is not a node in the digraph.