Essential things to remember from today's class (class 13, 4th October)

In recursion elimination, what happens if the stack is replaced with a queue,
   why that happens,
   why it is useful.

How the structure-ignoring tree comparer works, and
   why it couldn't be done recursively.

How to eliminate recursion without creating activation records, when that's possible.

What exactly iterative deepening is,
   why it does the same thing as using a queue,
   why it is usually more efficient than using a queue,
   And be sure you could implement it for yourself.