Plan for today:
* time, space, optimality, completeness for DFS, BFS.
* other search algorithms: uniform cost search, depth-limited, 
  iterative deepening, A*
  - time, space, optimality, completeness of some of those.
* talking about python and hw0.py some.  new version of hw0.py
* brainstorming improvements to hw0.py.
* logging into the cs server, basic linux/unix.
* tree search versus graph search.

Next week:
* heuristic searches, local search, CSP's.

Week after that:
* adversarial search, playing games!