def test_prufer():
# number of nodes is optional
assert Prufer([[0, 1], [0, 2], [0, 3], [0, 4]], 5).nodes == 5
assert Prufer([[0, 1], [0, 2], [0, 3], [0, 4]]).nodes == 5
a = Prufer([[0, 1], [0, 2], [0, 3], [0, 4]])
assert a.rank == 0
assert a.nodes == 5
assert a.prufer_repr == [0, 0, 0]
a = Prufer([[2, 4], [1, 4], [1, 3], [0, 5], [0, 4]])
assert a.rank == 924
assert a.nodes == 6
assert a.tree_repr == [[2, 4], [1, 4], [1, 3], [0, 5], [0, 4]]
assert a.prufer_repr == [4, 1, 4, 0]
assert Prufer.edges([0, 1, 2, 3], [1, 4, 5], [1, 4, 6]) == \
([[0, 1], [1, 2], [4, 6], [4, 5], [1, 4], [2, 3]], 7)
assert Prufer([0]*4).size == Prufer([6]*4).size == 1296
# accept iterables but convert to list of lists
tree = [(0, 1), (1, 5), (0, 3), (0, 2), (2, 6), (4, 7), (2, 4)]
Prufer(tree).tree_repr == tree
Prufer(set(tree)).tree_repr == tree
raises(ValueError, lambda: Prufer([[1, 2], [3, 4]])) # 0 is missing
assert Prufer(*Prufer.edges([1, 2], [3, 4])).prufer_repr == [1, 3]
raises(ValueError, lambda: Prufer.edges(
[1, 3], [3, 4])) # a broken tree but edges doesn't care
raises(ValueError, lambda: Prufer.edges([1, 2], [5, 6]))
def doit(t, b):
e, n = Prufer.edges(*t)
t = Prufer(e, n)
a = sorted(t.tree_repr)
b = [i - 1 for i in b]
assert t.prufer_repr == b
assert sorted(Prufer(b).tree_repr) == a
assert Prufer.unrank(t.rank, n).prufer_repr == b
def doit(t, b):
e, n = Prufer.edges(*t)
t = Prufer(e, n)
a = sorted(t.tree_repr)
b = [i - 1 for i in b]
assert t.prufer_repr == b
assert sorted(Prufer(b).tree_repr) == a
assert Prufer.unrank(t.rank, n).prufer_repr == b
