119 lines
No EOL
4.1 KiB
Text
119 lines
No EOL
4.1 KiB
Text
The Elves resume water filtering operations! Clean water starts flowing over the edge of Island Island.
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They offer to help *you* go over the edge of Island Island, too! Just hold on tight to one end of this impossibly long rope and they'll lower you down a safe distance from the massive waterfall you just created.
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As you finally reach Snow Island, you see that the water isn't really reaching the ground: it's being *absorbed by the air* itself. It looks like you'll finally have a little downtime while the moisture builds up to snow-producing levels. Snow Island is pretty scenic, even without any snow; why not take a walk?
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There's a map of nearby hiking trails (your puzzle input) that indicates *paths* (`.`), *forest* (`#`), and steep *slopes* (`^`, `>`, `v`, and `<`).
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For example:
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```
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#.#####################
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#.......#########...###
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#######.#########.#.###
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###.....#.>.>.###.#.###
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###v#####.#v#.###.#.###
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###.>...#.#.#.....#...#
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###v###.#.#.#########.#
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###...#.#.#.......#...#
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#####.#.#.#######.#.###
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#.....#.#.#.......#...#
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#.#####.#.#.#########v#
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#.#...#...#...###...>.#
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#.#.#v#######v###.###v#
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#...#.>.#...>.>.#.###.#
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#####v#.#.###v#.#.###.#
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#.....#...#...#.#.#...#
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#.#########.###.#.#.###
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#...###...#...#...#.###
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###.###.#.###v#####v###
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#...#...#.#.>.>.#.>.###
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#.###.###.#.###.#.#v###
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#.....###...###...#...#
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#####################.#
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```
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You're currently on the single path tile in the top row; your goal is to reach the single path tile in the bottom row. Because of all the mist from the waterfall, the slopes are probably quite *icy*; if you step onto a slope tile, your next step must be *downhill* (in the direction the arrow is pointing). To make sure you have the most scenic hike possible, *never step onto the same tile twice*. What is the longest hike you can take?
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In the example above, the longest hike you can take is marked with `O`, and your starting position is marked `S`:
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```
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#S#####################
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#OOOOOOO#########...###
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#######O#########.#.###
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###OOOOO#OOO>.###.#.###
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###O#####O#O#.###.#.###
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###OOOOO#O#O#.....#...#
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###v###O#O#O#########.#
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###...#O#O#OOOOOOO#...#
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#####.#O#O#######O#.###
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#.....#O#O#OOOOOOO#...#
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#.#####O#O#O#########v#
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#.#...#OOO#OOO###OOOOO#
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#.#.#v#######O###O###O#
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#...#.>.#...>OOO#O###O#
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#####v#.#.###v#O#O###O#
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#.....#...#...#O#O#OOO#
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#.#########.###O#O#O###
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#...###...#...#OOO#O###
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###.###.#.###v#####O###
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#...#...#.#.>.>.#.>O###
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#.###.###.#.###.#.#O###
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#.....###...###...#OOO#
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#####################O#
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```
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This hike contains `*94*` steps. (The other possible hikes you could have taken were `90`, `86`, `82`, `82`, and `74` steps long.)
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Find the longest hike you can take through the hiking trails listed on your map. *How many steps long is the longest hike?*
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Your puzzle answer was `2222`.
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\--- Part Two ---
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----------
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As you reach the trailhead, you realize that the ground isn't as slippery as you expected; you'll have *no problem* climbing up the steep slopes.
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Now, treat all *slopes* as if they were normal *paths* (`.`). You still want to make sure you have the most scenic hike possible, so continue to ensure that you *never step onto the same tile twice*. What is the longest hike you can take?
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In the example above, this increases the longest hike to `*154*` steps:
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```
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#S#####################
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#OOOOOOO#########OOO###
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#######O#########O#O###
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###OOOOO#.>OOO###O#O###
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###O#####.#O#O###O#O###
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###O>...#.#O#OOOOO#OOO#
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###O###.#.#O#########O#
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###OOO#.#.#OOOOOOO#OOO#
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#####O#.#.#######O#O###
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#OOOOO#.#.#OOOOOOO#OOO#
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#O#####.#.#O#########O#
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#O#OOO#...#OOO###...>O#
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#O#O#O#######O###.###O#
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#OOO#O>.#...>O>.#.###O#
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#####O#.#.###O#.#.###O#
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#OOOOO#...#OOO#.#.#OOO#
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#O#########O###.#.#O###
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#OOO###OOO#OOO#...#O###
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###O###O#O###O#####O###
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#OOO#OOO#O#OOO>.#.>O###
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#O###O###O#O###.#.#O###
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#OOOOO###OOO###...#OOO#
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#####################O#
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```
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Find the longest hike you can take through the surprisingly dry hiking trails listed on your map. *How many steps long is the longest hike?*
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Your puzzle answer was `6590`.
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Both parts of this puzzle are complete! They provide two gold stars: \*\*
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At this point, you should [return to your Advent calendar](/2023) and try another puzzle.
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If you still want to see it, you can [get your puzzle input](23/input). |