A beautiful logic puzzle that I found on Gurmeet’s puzzle collection, which he has attributed originally to K Rustan M Leino at Microsoft Research.
Consider five holes in a line. One of them is occupied by a fox. Each night, the fox moves to a neighboring hole, either to the left or to the right. Each morning, you get to inspect a hole of your choice. What strategy would ensure that the fox is eventually caught?
Please send your answers either directly on the blog site as comments, or to me at firstname.lastname@example.org. If you like the puzzle, please share it with others. If you have interesting puzzles to share, please send them to me at my e-mail given above.
Happy hide and seek with the fox!