Update README for day 8 part 2
This commit is contained in:
parent
2916647f99
commit
1939c709bd
@ -31,3 +31,43 @@ All of the trees around the edge of the grid are **visible** - since they are al
|
|||||||
With 16 trees visible on the edge and another 5 visible in the interior, a total of 21 trees are visible in this arrangement.
|
With 16 trees visible on the edge and another 5 visible in the interior, a total of 21 trees are visible in this arrangement.
|
||||||
|
|
||||||
**Consider your map; how many trees are visible from outside the grid?**
|
**Consider your map; how many trees are visible from outside the grid?**
|
||||||
|
|
||||||
|
## Part 2
|
||||||
|
|
||||||
|
Content with the amount of tree cover available, the Elves just need to know the best spot to build their tree house: they would like to be able to see a lot of trees.
|
||||||
|
|
||||||
|
To measure the viewing distance from a given tree, look up, down, left, and right from that tree; stop if you reach an edge or at the first tree that is the same height or taller than the tree under consideration. (If a tree is right on the edge, at least one of its viewing distances will be zero.)
|
||||||
|
|
||||||
|
The Elves don't care about distant trees taller than those found by the rules above; the proposed tree house has large eaves to keep it dry, so they wouldn't be able to see higher than the tree house anyway.
|
||||||
|
|
||||||
|
In the example above, consider the middle 5 in the second row:
|
||||||
|
|
||||||
|
30373
|
||||||
|
25512
|
||||||
|
65332
|
||||||
|
33549
|
||||||
|
35390
|
||||||
|
|
||||||
|
* Looking up, its view is not blocked; it can see 1 tree (of height 3).
|
||||||
|
* Looking left, its view is blocked immediately; it can see only 1 tree (of height 5, right next to it).
|
||||||
|
* Looking right, its view is not blocked; it can see 2 trees.
|
||||||
|
* Looking down, its view is blocked eventually; it can see 2 trees (one of height 3, then the tree of height 5 that blocks its view).
|
||||||
|
|
||||||
|
A tree's scenic score is found by multiplying together its viewing distance in each of the four directions. For this tree, this is 4 (found by multiplying 1 * 1 * 2 * 2).
|
||||||
|
|
||||||
|
However, you can do even better: consider the tree of height 5 in the middle of the fourth row:
|
||||||
|
|
||||||
|
30373
|
||||||
|
25512
|
||||||
|
65332
|
||||||
|
33549
|
||||||
|
35390
|
||||||
|
|
||||||
|
* Looking up, its view is blocked at 2 trees (by another tree with a height of 5).
|
||||||
|
* Looking left, its view is not blocked; it can see 2 trees.
|
||||||
|
* Looking down, its view is also not blocked; it can see 1 tree.
|
||||||
|
* Looking right, its view is blocked at 2 trees (by a massive tree of height 9).
|
||||||
|
|
||||||
|
This tree's scenic score is 8 (2 * 2 * 1 * 2); this is the ideal spot for the tree house.
|
||||||
|
|
||||||
|
Consider each tree on your map. What is the highest scenic score possible for any tree?
|
Reference in New Issue
Block a user