Problem
1. Which undirected graph representation is most appropriate for determining quickly whether or not a vertex is isolated (is connected to no other vertices)?
2. Suppose depth-first search is used on a binary search tree and the right edge taken before the left out of each node. In what order are the nodes visited?
3. How many bits of storage are required to represent the adjacency matrix for an undirected graph with V nodes and E edges, and how many are required for the adjacency list representation?