Case: Stairs
Clue of $N$
When we have a clue of , we know that lane must be in order from to .
| 5 | ||||||
| 4 | ||||||
| 3 | ||||||
| 2 | ||||||
| 1 | ||||||
| 5 |
Any other ordering, and we wouldn’t be able to see all skyscrapers – we’d have a taller one blocking a shorter one behind it.
Clue of $N$
When we have a clue of , we know that lane must be in order from to .
| 5 | ||||||
| 4 | ||||||
| 3 | ||||||
| 2 | ||||||
| 1 | ||||||
| 5 |
Any other ordering, and we wouldn’t be able to see all skyscrapers – we’d have a taller one blocking a shorter one behind it.