4 ms·
I'm confused, why must b push one of x, y, or z out? Why isn't one of x, y, or z already b? Or to put it another way, why can't a be the most-preferred non-acce
by eridius 8y ago
I'm confused, why must b push one of x, y, or z out? Why isn't one of x, y, or z already b? Or to put it another way, why can't a be the most-preferred non-accepted student for A?
- nemetroid 8y agoYou are right, I forgot to state an assumption, which is that "a gets pushed out of A" happens before "b gets pushed out of B" (and then goes on to apply to A). One of those things must happen before the other (each step in the algorithm is a currently-unassigned student applying to their next choice). In your case, if a is the most-preferred non-accepted student for A, then b must have been pushed out of B first, so the argument applies to B instead.