Some classic graphs
divisors n
builds the graph of divisors.
Vertices are integers from 2
to n
. i
is connected to j
if
and only if i
divides j
.
Invalid_argument
is n < 2
.
de_bruijn n
builds the de Bruijn graph of order n
.
Vertices are bit sequences of length n
(encoded as their
interpretation as binary integers). The sequence xw
is connected
to the sequence wy
for any bits x
and y
and any bit sequence
w
of length n-1
.
Invalid_argument
is n < 1
or n > Sys.word_size-1
.