Logic in the Blocks

Simple puzzles can give computers an unexpectedly strenuous workout

The parking-lot attendant at the trendy P’SPACE Club has a tough job. Whenever someone leaves the nightspot, she must retrieve the patron’s car from the crammed lot, often having to move other vehicles out of the way to clear a path to the exit. She has to do it quickly to earn a generous tip, but being efficient can be a real challenge.