Bases: sage.combinat.composition.Compositions_n
The class of signed compositions of .
EXAMPLES:
sage: SC3 = SignedCompositions(3); SC3
Signed compositions of 3
sage: SC3.cardinality()
18
sage: len(SC3.list())
18
sage: SC3.first()
[1, 1, 1]
sage: SC3.last()
[-3]
sage: SC3.random_element() # random
[1, -1, 1]
sage: SC3.list()
[[1, 1, 1],
[1, 1, -1],
[1, -1, 1],
[1, -1, -1],
[-1, 1, 1],
[-1, 1, -1],
[-1, -1, 1],
[-1, -1, -1],
[1, 2],
[1, -2],
[-1, 2],
[-1, -2],
[2, 1],
[2, -1],
[-2, 1],
[-2, -1],
[3],
[-3]]
TESTS:
sage: SC = SignedCompositions(3)
sage: TestSuite(SC).run()
Return the number of elements in self.
The number of signed compositions of is equal to
TESTS:
sage: SC4 = SignedCompositions(4)
sage: SC4.cardinality() == len(SC4.list())
True
sage: SignedCompositions(3).cardinality()
18