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provide alias number_of_longest_increasing_subsequences #40941

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provide alias number_of_longest_increasing_subsequences #40941

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10 changes: 6 additions & 4 deletions src/sage/combinat/permutation.py
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Original file line number Diff line number Diff line change
Expand Up @@ -61,7 +61,7 @@
:meth:`~sage.combinat.permutation.Permutation.runs` | Return a list of the runs in the permutation ``self``.
:meth:`~sage.combinat.permutation.Permutation.longest_increasing_subsequence_length` | Return the length of the longest increasing subsequences of ``self``.
:meth:`~sage.combinat.permutation.Permutation.longest_increasing_subsequences` | Return the list of the longest increasing subsequences of ``self``.
:meth:`~sage.combinat.permutation.Permutation.longest_increasing_subsequences_number` | Return the number of longest increasing subsequences
:meth:`~sage.combinat.permutation.Permutation.number_of_longest_increasing_subsequences` | Return the number of longest increasing subsequences
:meth:`~sage.combinat.permutation.Permutation.cycle_type` | Return the cycle type of ``self`` as a partition of ``len(self)``.
:meth:`~sage.combinat.permutation.Permutation.foata_bijection` | Return the image of the permutation ``self`` under the Foata bijection `\phi`.
:meth:`~sage.combinat.permutation.Permutation.foata_bijection_inverse` | Return the image of the permutation ``self`` under the inverse of the Foata bijection `\phi`.
Expand Down Expand Up @@ -2441,7 +2441,7 @@ def longest_increasing_subsequences(self) -> list:

return sorted([p[1:-1] for p in D.all_paths(0, n + 1)], reverse=True)

def longest_increasing_subsequences_number(self):
def number_of_longest_increasing_subsequences(self):
r"""
Return the number of increasing subsequences of maximal length
in ``self``.
Expand All @@ -2459,13 +2459,13 @@ def longest_increasing_subsequences_number(self):

EXAMPLES::

sage: sum(p.longest_increasing_subsequences_number()
sage: sum(p.number_of_longest_increasing_subsequences()
....: for p in Permutations(8))
120770

sage: p = Permutations(50).random_element()
sage: (len(p.longest_increasing_subsequences()) == # needs sage.graphs
....: p.longest_increasing_subsequences_number())
....: p.number_of_longest_increasing_subsequences())
True
"""
n = self.size()
Expand Down Expand Up @@ -2494,6 +2494,8 @@ def longest_increasing_subsequences_number(self):
count[x] += count[k]
return sum(count[x] for x in columns[-1])

longest_increasing_subsequences_number = number_of_longest_increasing_subsequences

def cycle_type(self):
r"""
Return a partition of ``len(self)`` corresponding to the cycle
Expand Down
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