The problem with union-find, where you need to draw states, etc.
has a discrepancy with the Baase text about the arguments
for the union operation.
For this problem, assume the arguments can be any two elements,
not necessarily the set-ids (or leaders) and assume that the
union operation internally calls find() to get the set-ids (or leaders)
for its arguments.
(CLRS assumes this too.)

Alternatively, assume the problem is restated by replacing
each call of the form union(X,Y) by union(find(X), find(Y))
and work it on that basis.

This file is clarify-rev-ex in the class directory.
--Allen

Clarification 2, union-find problem:

Another student pointed out that CLRS uses the opposite convention
for breaking ties -- the second argument remains as the root.
So do not follow the CLRS code blindly; adjust it so the first
argument remains as the root in this case.
--Allen