Symbol tables. First 6 minutes and last 3 minutes.
BSTs. It is particularly important that you understand the definition of a BST, as well as how to search and insert new keys. You should understand the recursive code, but it's ok if you don't quite fully grok every detail.
Deletion in BSTs. This is a tricky topic. We'll be going over this again in class, so it's ok if you don't quite understand everything. Make sure not to miss the deadpan delivery of "guarantree" at 9:30.
Elementary implementations of symbol tables. It's nice to know about the alternatives to BSTs for implementing a symbol table.
Ordered symbol table operations. While the notion is quite handy (and the presentation quite clear), it's not necessary to digest all of this before lecture.
Implementing ordered symbol table operations.
Symbol tables - Minutes 10 through 16 provide a good scription of the equals method (useful for programming assignment #4).