Cleanup

2024/day08/problem

@@ -0,0 +1,186 @@
+Advent of Code
+
+--- Day 8: Resonant Collinearity ---
+
+   You find yourselves on the [16]roof of a top-secret Easter Bunny
+   installation.
+
+   While The Historians do their thing, you take a look at the familiar huge
+   antenna. Much to your surprise, it seems to have been reconfigured to emit
+   a signal that makes people 0.1% more likely to buy Easter Bunny brand
+   Imitation Mediocre Chocolate as a Christmas gift! Unthinkable!
+
+   Scanning across the city, you find that there are actually many such
+   antennas. Each antenna is tuned to a specific frequency indicated by a
+   single lowercase letter, uppercase letter, or digit. You create a map
+   (your puzzle input) of these antennas. For example:
+
+ ............
+ ........0...
+ .....0......
+ .......0....
+ ....0.......
+ ......A.....
+ ............
+ ............
+ ........A...
+ .........A..
+ ............
+ ............
+
+   The signal only applies its nefarious effect at specific antinodes based
+   on the resonant frequencies of the antennas. In particular, an antinode
+   occurs at any point that is perfectly in line with two antennas of the
+   same frequency - but only when one of the antennas is twice as far away as
+   the other. This means that for any pair of antennas with the same
+   frequency, there are two antinodes, one on either side of them.
+
+   So, for these two antennas with frequency a, they create the two antinodes
+   marked with #:
+
+ ..........
+ ...#......
+ ..........
+ ....a.....
+ ..........
+ .....a....
+ ..........
+ ......#...
+ ..........
+ ..........
+
+   Adding a third antenna with the same frequency creates several more
+   antinodes. It would ideally add four antinodes, but two are off the right
+   side of the map, so instead it adds only two:
+
+ ..........
+ ...#......
+ #.........
+ ....a.....
+ ........a.
+ .....a....
+ ..#.......
+ ......#...
+ ..........
+ ..........
+
+   Antennas with different frequencies don't create antinodes; A and a count
+   as different frequencies. However, antinodes can occur at locations that
+   contain antennas. In this diagram, the lone antenna with frequency capital
+   A creates no antinodes but has a lowercase-a-frequency antinode at its
+   location:
+
+ ..........
+ ...#......
+ #.........
+ ....a.....
+ ........a.
+ .....a....
+ ..#.......
+ ......A...
+ ..........
+ ..........
+
+   The first example has antennas with two different frequencies, so the
+   antinodes they create look like this, plus an antinode overlapping the
+   topmost A-frequency antenna:
+
+ ......#....#
+ ...#....0...
+ ....#0....#.
+ ..#....0....
+ ....0....#..
+ .#....A.....
+ ...#........
+ #......#....
+ ........A...
+ .........A..
+ ..........#.
+ ..........#.
+
+   Because the topmost A-frequency antenna overlaps with a 0-frequency
+   antinode, there are 14 total unique locations that contain an antinode
+   within the bounds of the map.
+
+   Calculate the impact of the signal. How many unique locations within the
+   bounds of the map contain an antinode?
+
+   Your puzzle answer was 311.
+
+--- Part Two ---
+
+   Watching over your shoulder as you work, one of The Historians asks if you
+   took the effects of resonant harmonics into your calculations.
+
+   Whoops!
+
+   After updating your model, it turns out that an antinode occurs at any
+   grid position exactly in line with at least two antennas of the same
+   frequency, regardless of distance. This means that some of the new
+   antinodes will occur at the position of each antenna (unless that antenna
+   is the only one of its frequency).
+
+   So, these three T-frequency antennas now create many antinodes:
+
+ T....#....
+ ...T......
+ .T....#...
+ .........#
+ ..#.......
+ ..........
+ ...#......
+ ..........
+ ....#.....
+ ..........
+
+   In fact, the three T-frequency antennas are all exactly in line with two
+   antennas, so they are all also antinodes! This brings the total number of
+   antinodes in the above example to 9.
+
+   The original example now has 34 antinodes, including the antinodes that
+   appear on every antenna:
+
+ ##....#....#
+ .#.#....0...
+ ..#.#0....#.
+ ..##...0....
+ ....0....#..
+ .#...#A....#
+ ...#..#.....
+ #....#.#....
+ ..#.....A...
+ ....#....A..
+ .#........#.
+ ...#......##
+
+   Calculate the impact of the signal using this updated model. How many
+   unique locations within the bounds of the map contain an antinode?
+
+   Your puzzle answer was 1115.
+
+   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.
+
+References
+
+   Visible links
+   1. https://adventofcode.com/
+   2. https://adventofcode.com/2024/about
+   3. https://adventofcode.com/2024/events
+   4. https://cottonbureau.com/people/advent-of-code
+   5. https://adventofcode.com/2024/settings
+   6. https://adventofcode.com/2024/auth/logout
+   7. Advent of Code Supporter
+	https://adventofcode.com/2024/support
+   8. https://adventofcode.com/2024
+   9. https://adventofcode.com/2024
+  10. https://adventofcode.com/2024/support
+  12. https://adventofcode.com/2024/leaderboard
+  13. https://adventofcode.com/2024/stats
+  16. https://adventofcode.com/2016/day/25
+  17. https://adventofcode.com/2024
+  18. https://adventofcode.com/2024/day/8/input