Some work on AOC script. Needs more
This commit is contained in:
198
2023/day11/problem
Normal file
198
2023/day11/problem
Normal file
@@ -0,0 +1,198 @@
|
||||
[1]Advent of Code
|
||||
|
||||
• [2][About]
|
||||
• [3][Events]
|
||||
• [4][Shop]
|
||||
• [5][Settings]
|
||||
• [6][Log Out]
|
||||
|
||||
br0xen [7](AoC++) 36*
|
||||
|
||||
$year=[8]2023;
|
||||
|
||||
• [9][Calendar]
|
||||
• [10][AoC++]
|
||||
• [11][Sponsors]
|
||||
• [12][Leaderboard]
|
||||
• [13][Stats]
|
||||
|
||||
Our [14]sponsors help make Advent of Code possible:
|
||||
[15]McGraw Hill - Transforming education, one line of code at a time.
|
||||
|
||||
--- Day 11: Cosmic Expansion ---
|
||||
|
||||
You continue following signs for "Hot Springs" and eventually come across
|
||||
an [16]observatory. The Elf within turns out to be a researcher studying
|
||||
cosmic expansion using the giant telescope here.
|
||||
|
||||
He doesn't know anything about the missing machine parts; he's only
|
||||
visiting for this research project. However, he confirms that the hot
|
||||
springs are the next-closest area likely to have people; he'll even take
|
||||
you straight there once he's done with today's observation analysis.
|
||||
|
||||
Maybe you can help him with the analysis to speed things up?
|
||||
|
||||
The researcher has collected a bunch of data and compiled the data into a
|
||||
single giant image (your puzzle input). The image includes empty space (.)
|
||||
and galaxies (#). For example:
|
||||
|
||||
...#......
|
||||
.......#..
|
||||
#.........
|
||||
..........
|
||||
......#...
|
||||
.#........
|
||||
.........#
|
||||
..........
|
||||
.......#..
|
||||
#...#.....
|
||||
|
||||
The researcher is trying to figure out the sum of the lengths of the
|
||||
shortest path between every pair of galaxies. However, there's a catch:
|
||||
the universe expanded in the time it took the light from those galaxies to
|
||||
reach the observatory.
|
||||
|
||||
Due to something involving gravitational effects, only some space expands.
|
||||
In fact, the result is that any rows or columns that contain no galaxies
|
||||
should all actually be twice as big.
|
||||
|
||||
In the above example, three columns and two rows contain no galaxies:
|
||||
|
||||
v v v
|
||||
...#......
|
||||
.......#..
|
||||
#.........
|
||||
>..........<
|
||||
......#...
|
||||
.#........
|
||||
.........#
|
||||
>..........<
|
||||
.......#..
|
||||
#...#.....
|
||||
^ ^ ^
|
||||
|
||||
These rows and columns need to be twice as big; the result of cosmic
|
||||
expansion therefore looks like this:
|
||||
|
||||
....#........
|
||||
.........#...
|
||||
#............
|
||||
.............
|
||||
.............
|
||||
........#....
|
||||
.#...........
|
||||
............#
|
||||
.............
|
||||
.............
|
||||
.........#...
|
||||
#....#.......
|
||||
|
||||
Equipped with this expanded universe, the shortest path between every pair
|
||||
of galaxies can be found. It can help to assign every galaxy a unique
|
||||
number:
|
||||
|
||||
....1........
|
||||
.........2...
|
||||
3............
|
||||
.............
|
||||
.............
|
||||
........4....
|
||||
.5...........
|
||||
............6
|
||||
.............
|
||||
.............
|
||||
.........7...
|
||||
8....9.......
|
||||
|
||||
In these 9 galaxies, there are 36 pairs. Only count each pair once; order
|
||||
within the pair doesn't matter. For each pair, find any shortest path
|
||||
between the two galaxies using only steps that move up, down, left, or
|
||||
right exactly one . or # at a time. (The shortest path between two
|
||||
galaxies is allowed to pass through another galaxy.)
|
||||
|
||||
For example, here is one of the shortest paths between galaxies 5 and 9:
|
||||
|
||||
....1........
|
||||
.........2...
|
||||
3............
|
||||
.............
|
||||
.............
|
||||
........4....
|
||||
.5...........
|
||||
.##.........6
|
||||
..##.........
|
||||
...##........
|
||||
....##...7...
|
||||
8....9.......
|
||||
|
||||
This path has length 9 because it takes a minimum of nine steps to get
|
||||
from galaxy 5 to galaxy 9 (the eight locations marked # plus the step onto
|
||||
galaxy 9 itself). Here are some other example shortest path lengths:
|
||||
|
||||
• Between galaxy 1 and galaxy 7: 15
|
||||
• Between galaxy 3 and galaxy 6: 17
|
||||
• Between galaxy 8 and galaxy 9: 5
|
||||
|
||||
In this example, after expanding the universe, the sum of the shortest
|
||||
path between all 36 pairs of galaxies is 374.
|
||||
|
||||
Expand the universe, then find the length of the shortest path between
|
||||
every pair of galaxies. What is the sum of these lengths?
|
||||
|
||||
Your puzzle answer was 9957702.
|
||||
|
||||
--- Part Two ---
|
||||
|
||||
The galaxies are much older (and thus much farther apart) than the
|
||||
researcher initially estimated.
|
||||
|
||||
Now, instead of the expansion you did before, make each empty row or
|
||||
column one million times larger. That is, each empty row should be
|
||||
replaced with 1000000 empty rows, and each empty column should be replaced
|
||||
with 1000000 empty columns.
|
||||
|
||||
(In the example above, if each empty row or column were merely 10 times
|
||||
larger, the sum of the shortest paths between every pair of galaxies would
|
||||
be 1030. If each empty row or column were merely 100 times larger, the sum
|
||||
of the shortest paths between every pair of galaxies would be 8410.
|
||||
However, your universe will need to expand far beyond these values.)
|
||||
|
||||
Starting with the same initial image, expand the universe according to
|
||||
these new rules, then find the length of the shortest path between every
|
||||
pair of galaxies. What is the sum of these lengths?
|
||||
|
||||
Your puzzle answer was 512240933238.
|
||||
|
||||
Both parts of this puzzle are complete! They provide two gold stars: **
|
||||
|
||||
At this point, you should [17]return to your Advent calendar and try
|
||||
another puzzle.
|
||||
|
||||
If you still want to see it, you can [18]get your puzzle input.
|
||||
|
||||
You can also [Shareon [19]Twitter [20]Mastodon] this puzzle.
|
||||
|
||||
References
|
||||
|
||||
Visible links
|
||||
1. https://adventofcode.com/
|
||||
2. https://adventofcode.com/2023/about
|
||||
3. https://adventofcode.com/2023/events
|
||||
4. https://teespring.com/stores/advent-of-code
|
||||
5. https://adventofcode.com/2023/settings
|
||||
6. https://adventofcode.com/2023/auth/logout
|
||||
7. Advent of Code Supporter
|
||||
https://adventofcode.com/2023/support
|
||||
8. https://adventofcode.com/2023
|
||||
9. https://adventofcode.com/2023
|
||||
10. https://adventofcode.com/2023/support
|
||||
11. https://adventofcode.com/2023/sponsors
|
||||
12. https://adventofcode.com/2023/leaderboard
|
||||
13. https://adventofcode.com/2023/stats
|
||||
14. https://adventofcode.com/2023/sponsors
|
||||
15. https://mheducation.com/
|
||||
16. https://en.wikipedia.org/wiki/Observatory
|
||||
17. https://adventofcode.com/2023
|
||||
18. https://adventofcode.com/2023/day/11/input
|
||||
19. https://twitter.com/intent/tweet?text=I%27ve+completed+%22Cosmic+Expansion%22+%2D+Day+11+%2D+Advent+of+Code+2023&url=https%3A%2F%2Fadventofcode%2Ecom%2F2023%2Fday%2F11&related=ericwastl&hashtags=AdventOfCode
|
||||
20. javascript:void(0);
|
||||
Reference in New Issue
Block a user