The Cat and Mouse Juxtaposition

In a house, there are nnn rooms in a line, with the rooms being numbered from 111 to nnn from the left to the right. In each room, there are two doors, allowing someone to move from his current room to the room to his left or to the room his right. Two exceptions to this are the rooms numbered 111 and nnn, which only have doors to their right and left respectively since there’s no room to the left of room 111, and no room to the right of room nnn.

This is a companion discussion topic for the original entry at