What algorithms (brute force or not) would I use to put in as many cars (assume all cars are the same size) in a parking lot so that there is at least one exit (from the container) and a car cannot be blocked. Or can someone show me an example of this problem solved programmatically.

The parking lot varies in shape would be nice but if you want to assume its some invariant shape that is fine.

Another Edit: Assume that driving distance in the parking lot is not a factor (although it would be totally awesome if it was weighted factor to number of cars in lot).

Another Edit: Assume 2 Dimensional (no cranes or driving over cars).

Another Edit: You cannot move cars around once they are parked (its not a valet parking lot).

I hope the question is specific enough now.