Clay Mathematics Institute: Ian Stewart on Minesweeper

As a side note, if you enjoy playing Minesweeper but don't like losing to a bad guess, you might want to try the implementation in Simon Tatham's puzzle collection:

http://www.chiark.greenend.org.uk/~sgtatham/puzzles/

Unlike most other implementations, it only generates boards that can be solved by logic, so you never need to guess; your first square is guaranteed to be safe and to reveal enough information to progress.

(IIRC, the algorithm used to pre-solve each generated level bottoms out in an exhaustive search, so I guess this game variant is still in NP.)

Maybe I should read more, but this is the clearest explanation of P vs NP I've read so far.

I will be interviewing Ian soon for Math-Blog.com. If you have any specific questions you think I should ask him, please feel free to let me know.

I've submitted an interview with Ian Stewart here: http://news.ycombinator.com/item?id=1594526

He's a serious mathematician, and a serious writer of both fiction and non-fiction.

Figure 3 is incomplete; as the space depicted in it is not a valid board configuration. If either x or x' is false, then the respective 1s on the extreme sides will be invalid. This is either a crop of a real situation (in which we assume the wire repeats beyond the scope of the image), or an error.