499 lines
11 KiB
Plaintext
499 lines
11 KiB
Plaintext
Advent of Code
|
||
|
||
--- Day 15: Warehouse Woes ---
|
||
|
||
You appear back inside your own mini submarine! Each Historian drives
|
||
their mini submarine in a different direction; maybe the Chief has his own
|
||
submarine down here somewhere as well?
|
||
|
||
You look up to see a vast school of [16]lanternfish swimming past you. On
|
||
closer inspection, they seem quite anxious, so you drive your mini
|
||
submarine over to see if you can help.
|
||
|
||
Because lanternfish populations grow rapidly, they need a lot of food, and
|
||
that food needs to be stored somewhere. That's why these lanternfish have
|
||
built elaborate warehouse complexes operated by robots!
|
||
|
||
These lanternfish seem so anxious because they have lost control of the
|
||
robot that operates one of their most important warehouses! It is
|
||
currently running amok, pushing around boxes in the warehouse with no
|
||
regard for lanternfish logistics or lanternfish inventory management
|
||
strategies.
|
||
|
||
Right now, none of the lanternfish are brave enough to swim up to an
|
||
unpredictable robot so they could shut it off. However, if you could
|
||
anticipate the robot's movements, maybe they could find a safe option.
|
||
|
||
The lanternfish already have a map of the warehouse and a list of
|
||
movements the robot will attempt to make (your puzzle input). The problem
|
||
is that the movements will sometimes fail as boxes are shifted around,
|
||
making the actual movements of the robot difficult to predict.
|
||
|
||
For example:
|
||
|
||
##########
|
||
#..O..O.O#
|
||
#......O.#
|
||
#.OO..O.O#
|
||
#..O@..O.#
|
||
#O#..O...#
|
||
#O..O..O.#
|
||
#.OO.O.OO#
|
||
#....O...#
|
||
##########
|
||
|
||
<vv>^<v^>v>^vv^v>v<>v^v<v<^vv<<<^><<><>>v<vvv<>^v^>^<<<><<v<<<v^vv^v>^
|
||
vvv<<^>^v^^><<>>><>^<<><^vv^^<>vvv<>><^^v>^>vv<>v<<<<v<^v>^<^^>>>^<v<v
|
||
><>vv>v^v^<>><>>>><^^>vv>v<^^^>>v^v^<^^>v^^>v^<^v>v<>>v^v^<v>v^^<^^vv<
|
||
<<v<^>>^^^^>>>v^<>vvv^><v<<<>^^^vv^<vvv>^>v<^^^^v<>^>vvvv><>>v^<<^^^^^
|
||
^><^><>>><>^^<<^^v>>><^<v>^<vv>>v>>>^v><>^v><<<<v>>v<v<v>vvv>^<><<>^><
|
||
^>><>^v<><^vvv<^^<><v<<<<<><^v<<<><<<^^<v<^^^><^>>^<v^><<<^>>^v<v^v<v^
|
||
>^>>^v>vv>^<<^v<>><<><<v<<v><>v<^vv<<<>^^v^>^^>>><<^v>>v^v><^^>>^<>vv^
|
||
<><^^>^^^<><vvvvv^v<v<<>^v<v>v<<^><<><<><<<^^<<<^<<>><<><^^^>^^<>^>v<>
|
||
^^>vv<^v^v<vv>^<><v<^v>^^^>>>^^vvv^>vvv<>>>^<^>>>>>^<<^v>^vvv<>^<><<v>
|
||
v^^>>><<^^<>>^v^<v^vv<>v^<<>^<^v^v><^<<<><<^<v><v<>vv>>v><v^<vv<>v^<<^
|
||
|
||
As the robot (@) attempts to move, if there are any boxes (O) in the way,
|
||
the robot will also attempt to push those boxes. However, if this action
|
||
would cause the robot or a box to move into a wall (#), nothing moves
|
||
instead, including the robot. The initial positions of these are shown on
|
||
the map at the top of the document the lanternfish gave you.
|
||
|
||
The rest of the document describes the moves (^ for up, v for down, < for
|
||
left, > for right) that the robot will attempt to make, in order. (The
|
||
moves form a single giant sequence; they are broken into multiple lines
|
||
just to make copy-pasting easier. Newlines within the move sequence should
|
||
be ignored.)
|
||
|
||
Here is a smaller example to get started:
|
||
|
||
########
|
||
#..O.O.#
|
||
##@.O..#
|
||
#...O..#
|
||
#.#.O..#
|
||
#...O..#
|
||
#......#
|
||
########
|
||
|
||
<^^>>>vv<v>>v<<
|
||
|
||
Were the robot to attempt the given sequence of moves, it would push
|
||
around the boxes as follows:
|
||
|
||
Initial state:
|
||
########
|
||
#..O.O.#
|
||
##@.O..#
|
||
#...O..#
|
||
#.#.O..#
|
||
#...O..#
|
||
#......#
|
||
########
|
||
|
||
Move <:
|
||
########
|
||
#..O.O.#
|
||
##@.O..#
|
||
#...O..#
|
||
#.#.O..#
|
||
#...O..#
|
||
#......#
|
||
########
|
||
|
||
Move ^:
|
||
########
|
||
#.@O.O.#
|
||
##..O..#
|
||
#...O..#
|
||
#.#.O..#
|
||
#...O..#
|
||
#......#
|
||
########
|
||
|
||
Move ^:
|
||
########
|
||
#.@O.O.#
|
||
##..O..#
|
||
#...O..#
|
||
#.#.O..#
|
||
#...O..#
|
||
#......#
|
||
########
|
||
|
||
Move >:
|
||
########
|
||
#..@OO.#
|
||
##..O..#
|
||
#...O..#
|
||
#.#.O..#
|
||
#...O..#
|
||
#......#
|
||
########
|
||
|
||
Move >:
|
||
########
|
||
#...@OO#
|
||
##..O..#
|
||
#...O..#
|
||
#.#.O..#
|
||
#...O..#
|
||
#......#
|
||
########
|
||
|
||
Move >:
|
||
########
|
||
#...@OO#
|
||
##..O..#
|
||
#...O..#
|
||
#.#.O..#
|
||
#...O..#
|
||
#......#
|
||
########
|
||
|
||
Move v:
|
||
########
|
||
#....OO#
|
||
##..@..#
|
||
#...O..#
|
||
#.#.O..#
|
||
#...O..#
|
||
#...O..#
|
||
########
|
||
|
||
Move v:
|
||
########
|
||
#....OO#
|
||
##..@..#
|
||
#...O..#
|
||
#.#.O..#
|
||
#...O..#
|
||
#...O..#
|
||
########
|
||
|
||
Move <:
|
||
########
|
||
#....OO#
|
||
##.@...#
|
||
#...O..#
|
||
#.#.O..#
|
||
#...O..#
|
||
#...O..#
|
||
########
|
||
|
||
Move v:
|
||
########
|
||
#....OO#
|
||
##.....#
|
||
#..@O..#
|
||
#.#.O..#
|
||
#...O..#
|
||
#...O..#
|
||
########
|
||
|
||
Move >:
|
||
########
|
||
#....OO#
|
||
##.....#
|
||
#...@O.#
|
||
#.#.O..#
|
||
#...O..#
|
||
#...O..#
|
||
########
|
||
|
||
Move >:
|
||
########
|
||
#....OO#
|
||
##.....#
|
||
#....@O#
|
||
#.#.O..#
|
||
#...O..#
|
||
#...O..#
|
||
########
|
||
|
||
Move v:
|
||
########
|
||
#....OO#
|
||
##.....#
|
||
#.....O#
|
||
#.#.O@.#
|
||
#...O..#
|
||
#...O..#
|
||
########
|
||
|
||
Move <:
|
||
########
|
||
#....OO#
|
||
##.....#
|
||
#.....O#
|
||
#.#O@..#
|
||
#...O..#
|
||
#...O..#
|
||
########
|
||
|
||
Move <:
|
||
########
|
||
#....OO#
|
||
##.....#
|
||
#.....O#
|
||
#.#O@..#
|
||
#...O..#
|
||
#...O..#
|
||
########
|
||
|
||
The larger example has many more moves; after the robot has finished those
|
||
moves, the warehouse would look like this:
|
||
|
||
##########
|
||
#.O.O.OOO#
|
||
#........#
|
||
#OO......#
|
||
#OO@.....#
|
||
#O#.....O#
|
||
#O.....OO#
|
||
#O.....OO#
|
||
#OO....OO#
|
||
##########
|
||
|
||
The lanternfish use their own custom Goods Positioning System (GPS for
|
||
short) to track the locations of the boxes. The GPS coordinate of a box is
|
||
equal to 100 times its distance from the top edge of the map plus its
|
||
distance from the left edge of the map. (This process does not stop at
|
||
wall tiles; measure all the way to the edges of the map.)
|
||
|
||
So, the box shown below has a distance of 1 from the top edge of the map
|
||
and 4 from the left edge of the map, resulting in a GPS coordinate of 100
|
||
* 1 + 4 = 104.
|
||
|
||
#######
|
||
#...O..
|
||
#......
|
||
|
||
The lanternfish would like to know the sum of all boxes' GPS coordinates
|
||
after the robot finishes moving. In the larger example, the sum of all
|
||
boxes' GPS coordinates is 10092. In the smaller example, the sum is 2028.
|
||
|
||
Predict the motion of the robot and boxes in the warehouse. After the
|
||
robot is finished moving, what is the sum of all boxes' GPS coordinates?
|
||
|
||
Your puzzle answer was 1527563.
|
||
|
||
--- Part Two ---
|
||
|
||
The lanternfish use your information to find a safe moment to swim in and
|
||
turn off the malfunctioning robot! Just as they start preparing a festival
|
||
in your honor, reports start coming in that a second warehouse's robot is
|
||
also malfunctioning.
|
||
|
||
This warehouse's layout is surprisingly similar to the one you just
|
||
helped. There is one key difference: everything except the robot is twice
|
||
as wide! The robot's list of movements doesn't change.
|
||
|
||
To get the wider warehouse's map, start with your original map and, for
|
||
each tile, make the following changes:
|
||
|
||
• If the tile is #, the new map contains ## instead.
|
||
• If the tile is O, the new map contains [] instead.
|
||
• If the tile is ., the new map contains .. instead.
|
||
• If the tile is @, the new map contains @. instead.
|
||
|
||
This will produce a new warehouse map which is twice as wide and with wide
|
||
boxes that are represented by []. (The robot does not change size.)
|
||
|
||
The larger example from before would now look like this:
|
||
|
||
####################
|
||
##....[]....[]..[]##
|
||
##............[]..##
|
||
##..[][]....[]..[]##
|
||
##....[]@.....[]..##
|
||
##[]##....[]......##
|
||
##[]....[]....[]..##
|
||
##..[][]..[]..[][]##
|
||
##........[]......##
|
||
####################
|
||
|
||
Because boxes are now twice as wide but the robot is still the same size
|
||
and speed, boxes can be aligned such that they directly push two other
|
||
boxes at once. For example, consider this situation:
|
||
|
||
#######
|
||
#...#.#
|
||
#.....#
|
||
#..OO@#
|
||
#..O..#
|
||
#.....#
|
||
#######
|
||
|
||
<vv<<^^<<^^
|
||
|
||
After appropriately resizing this map, the robot would push around these
|
||
boxes as follows:
|
||
|
||
Initial state:
|
||
##############
|
||
##......##..##
|
||
##..........##
|
||
##....[][]@.##
|
||
##....[]....##
|
||
##..........##
|
||
##############
|
||
|
||
Move <:
|
||
##############
|
||
##......##..##
|
||
##..........##
|
||
##...[][]@..##
|
||
##....[]....##
|
||
##..........##
|
||
##############
|
||
|
||
Move v:
|
||
##############
|
||
##......##..##
|
||
##..........##
|
||
##...[][]...##
|
||
##....[].@..##
|
||
##..........##
|
||
##############
|
||
|
||
Move v:
|
||
##############
|
||
##......##..##
|
||
##..........##
|
||
##...[][]...##
|
||
##....[]....##
|
||
##.......@..##
|
||
##############
|
||
|
||
Move <:
|
||
##############
|
||
##......##..##
|
||
##..........##
|
||
##...[][]...##
|
||
##....[]....##
|
||
##......@...##
|
||
##############
|
||
|
||
Move <:
|
||
##############
|
||
##......##..##
|
||
##..........##
|
||
##...[][]...##
|
||
##....[]....##
|
||
##.....@....##
|
||
##############
|
||
|
||
Move ^:
|
||
##############
|
||
##......##..##
|
||
##...[][]...##
|
||
##....[]....##
|
||
##.....@....##
|
||
##..........##
|
||
##############
|
||
|
||
Move ^:
|
||
##############
|
||
##......##..##
|
||
##...[][]...##
|
||
##....[]....##
|
||
##.....@....##
|
||
##..........##
|
||
##############
|
||
|
||
Move <:
|
||
##############
|
||
##......##..##
|
||
##...[][]...##
|
||
##....[]....##
|
||
##....@.....##
|
||
##..........##
|
||
##############
|
||
|
||
Move <:
|
||
##############
|
||
##......##..##
|
||
##...[][]...##
|
||
##....[]....##
|
||
##...@......##
|
||
##..........##
|
||
##############
|
||
|
||
Move ^:
|
||
##############
|
||
##......##..##
|
||
##...[][]...##
|
||
##...@[]....##
|
||
##..........##
|
||
##..........##
|
||
##############
|
||
|
||
Move ^:
|
||
##############
|
||
##...[].##..##
|
||
##...@.[]...##
|
||
##....[]....##
|
||
##..........##
|
||
##..........##
|
||
##############
|
||
|
||
This warehouse also uses GPS to locate the boxes. For these larger boxes,
|
||
distances are measured from the edge of the map to the closest edge of the
|
||
box in question. So, the box shown below has a distance of 1 from the top
|
||
edge of the map and 5 from the left edge of the map, resulting in a GPS
|
||
coordinate of 100 * 1 + 5 = 105.
|
||
|
||
##########
|
||
##...[]...
|
||
##........
|
||
|
||
In the scaled-up version of the larger example from above, after the robot
|
||
has finished all of its moves, the warehouse would look like this:
|
||
|
||
####################
|
||
##[].......[].[][]##
|
||
##[]...........[].##
|
||
##[]........[][][]##
|
||
##[]......[]....[]##
|
||
##..##......[]....##
|
||
##..[]............##
|
||
##..@......[].[][]##
|
||
##......[][]..[]..##
|
||
####################
|
||
|
||
The sum of these boxes' GPS coordinates is 9021.
|
||
|
||
Predict the motion of the robot and boxes in this new, scaled-up
|
||
warehouse. What is the sum of all boxes' final GPS coordinates?
|
||
|
||
Your puzzle answer was 1521635.
|
||
|
||
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
|
||
11. https://adventofcode.com/2024/sponsors
|
||
12. https://adventofcode.com/2024/leaderboard
|
||
13. https://adventofcode.com/2024/stats
|
||
16. https://adventofcode.com/2021/day/6
|
||
17. https://adventofcode.com/2024
|
||
18. https://adventofcode.com/2024/day/15/input
|