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