Keeping Size Up-To-Date

• CREATE: initializes to 0

• INSERT: increments by 1

• DELETE: decrements by 1

• JOIN: that's on the assignment!

• SPLIT(L1,L2,W): to update the size of both L1 and L2, we need to know how far down L1 the split occurs.
  • zipping down one list and counting isn't constant time.

  • each node could be augmented with its position: but that info would also have to be updated after a SPLIT (zip down L2).