The Twelvefold Way#
three variables:
labelling of balls
labelling of boxes
at most 1 ball, at least one ball, or any number of balls
problems conceptually in a
2 2 3
arrayrichard stanley and that other guy
twelvefold table, partially filled in with already seen problems
we’re going to explore the rest of the problems, and enumerate possibilities for each
Implementing the Twelvefold Way#
for each function, we can either have ball → box mappings, or box → ball mappings, or both!
for more information
sudley place for nars2000 apl stuff
taocp4a for imperative generation algorithms - we’re doing recursive implementations
permutation function from aplcart