Lecture 4 notes are up

Hi, I've put the notes for lecture 4 (analysis of algorithms) up. They are slightly different than the ones handed out in lecture. In particular, they correct an error on the last 4 slides on the intuition behind the master method. The amount of work done per level is a^i*f(n/b^i) at the i'th level in the tree. The notes handed out in class incorrectly listed the amount of work as a^i*f(n). Sorry for the confusion. I will go over this briefly in class on Tuesday.