Insight · ★★★★☆ · ~8 min
Catching the Spy
A spy hops ±1 each night on a line of rooms. Can you always catch it?
by MindYourPuzzle
A spy moves between 4 connected rooms in a line (1-2-3-4). The spy moves to an adjacent room each night. You can search one room per night. Can you guarantee catching the spy?
Hints