Exam #2: extra credit

Hint: You need to handle overflow/underflow in such a way that 2/3 minimum occupancy is preserved. This means splitting 2 nodes into 3 on overflow (when a neighbor is full) and merging 3 nodes into 2
on underflow (when both neighbors are at their minimum). Special nodes arise in the exceptional cases when split/merge cannot be applied and have to be handled separately.

This is different than in B+trees.

--jc