From e1c0af83d30c0e7e39da561a466af69634009b9d Mon Sep 17 00:00:00 2001 From: Burnus Date: Mon, 24 Apr 2023 21:54:51 +0200 Subject: [PATCH] Added Solution for 2021 day 11 --- 2021/day11_dumbo_octopus/Cargo.toml | 8 + 2021/day11_dumbo_octopus/challenge.txt | 367 ++++++++++++++++++ 2021/day11_dumbo_octopus/src/lib.rs | 97 +++++ .../day11_dumbo_octopus/tests/challenge_input | 10 + 2021/day11_dumbo_octopus/tests/sample_input | 10 + 5 files changed, 492 insertions(+) create mode 100644 2021/day11_dumbo_octopus/Cargo.toml create mode 100644 2021/day11_dumbo_octopus/challenge.txt create mode 100644 2021/day11_dumbo_octopus/src/lib.rs create mode 100644 2021/day11_dumbo_octopus/tests/challenge_input create mode 100644 2021/day11_dumbo_octopus/tests/sample_input diff --git a/2021/day11_dumbo_octopus/Cargo.toml b/2021/day11_dumbo_octopus/Cargo.toml new file mode 100644 index 0000000..de0a97e --- /dev/null +++ b/2021/day11_dumbo_octopus/Cargo.toml @@ -0,0 +1,8 @@ +[package] +name = "day11_dumbo_octopus" +version = "0.1.0" +edition = "2021" + +# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html + +[dependencies] diff --git a/2021/day11_dumbo_octopus/challenge.txt b/2021/day11_dumbo_octopus/challenge.txt new file mode 100644 index 0000000..f2979e3 --- /dev/null +++ b/2021/day11_dumbo_octopus/challenge.txt @@ -0,0 +1,367 @@ +You enter a large cavern full of rare bioluminescent [dumbo octopuses](https://www.youtube.com/watch?v=eih-VSaS2g0)! They seem to not like the Christmas lights on your submarine, so you turn them off for now. + +There are 100 octopuses arranged neatly in a 10 by 10 grid. Each octopus slowly gains *energy* over time and *flashes* brightly for a moment when its energy is full. Although your lights are off, maybe you could navigate through the cave without disturbing the octopuses if you could predict when the flashes of light will happen. + +Each octopus has an *energy level* - your submarine can remotely measure the energy level of each octopus (your puzzle input). For example: + +``` +5483143223 +2745854711 +5264556173 +6141336146 +6357385478 +4167524645 +2176841721 +6882881134 +4846848554 +5283751526 + +``` + +The energy level of each octopus is a value between `0` and `9`. Here, the top-left octopus has an energy level of `5`, the bottom-right one has an energy level of `6`, and so on. + +You can model the energy levels and flashes of light in *steps*. During a single step, the following occurs: + +* First, the energy level of each octopus increases by `1`. +* Then, any octopus with an energy level greater than `9` *flashes*. This increases the energy level of all adjacent octopuses by `1`, including octopuses that are diagonally adjacent. If this causes an octopus to have an energy level greater than `9`, it *also flashes*. This process continues as long as new octopuses keep having their energy level increased beyond `9`. (An octopus can only flash *at most once per step*.) +* Finally, any octopus that flashed during this step has its energy level set to `0`, as it used all of its energy to flash. + +Adjacent flashes can cause an octopus to flash on a step even if it begins that step with very little energy. Consider the middle octopus with `1` energy in this situation: + +``` +Before any steps: +11111 +19991 +19191 +19991 +11111 + +After step 1: +34543 +40004 +50005 +40004 +34543 + +After step 2: +45654 +51115 +61116 +51115 +45654 + +``` + +An octopus is *highlighted* when it flashed during the given step. + +Here is how the larger example above progresses: + +``` +Before any steps: +5483143223 +2745854711 +5264556173 +6141336146 +6357385478 +4167524645 +2176841721 +6882881134 +4846848554 +5283751526 + +After step 1: +6594254334 +3856965822 +6375667284 +7252447257 +7468496589 +5278635756 +3287952832 +7993992245 +5957959665 +6394862637 + +After step 2: +8807476555 +5089087054 +8597889608 +8485769600 +8700908800 +6600088989 +6800005943 +0000007456 +9000000876 +8700006848 + +After step 3: +0050900866 +8500800575 +9900000039 +9700000041 +9935080063 +7712300000 +7911250009 +2211130000 +0421125000 +0021119000 + +After step 4: +2263031977 +0923031697 +0032221150 +0041111163 +0076191174 +0053411122 +0042361120 +5532241122 +1532247211 +1132230211 + +After step 5: +4484144000 +2044144000 +2253333493 +1152333274 +1187303285 +1164633233 +1153472231 +6643352233 +2643358322 +2243341322 + +After step 6: +5595255111 +3155255222 +3364444605 +2263444496 +2298414396 +2275744344 +2264583342 +7754463344 +3754469433 +3354452433 + +After step 7: +6707366222 +4377366333 +4475555827 +3496655709 +3500625609 +3509955566 +3486694453 +8865585555 +4865580644 +4465574644 + +After step 8: +7818477333 +5488477444 +5697666949 +4608766830 +4734946730 +4740097688 +6900007564 +0000009666 +8000004755 +6800007755 + +After step 9: +9060000644 +7800000976 +6900000080 +5840000082 +5858000093 +6962400000 +8021250009 +2221130009 +9111128097 +7911119976 + +After step 10: +0481112976 +0031112009 +0041112504 +0081111406 +0099111306 +0093511233 +0442361130 +5532252350 +0532250600 +0032240000 + +``` + +After step 10, there have been a total of `204` flashes. Fast forwarding, here is the same configuration every 10 steps: + +``` +After step 20: +3936556452 +5686556806 +4496555690 +4448655580 +4456865570 +5680086577 +7000009896 +0000000344 +6000000364 +4600009543 + +After step 30: +0643334118 +4253334611 +3374333458 +2225333337 +2229333338 +2276733333 +2754574565 +5544458511 +9444447111 +7944446119 + +After step 40: +6211111981 +0421111119 +0042111115 +0003111115 +0003111116 +0065611111 +0532351111 +3322234597 +2222222976 +2222222762 + +After step 50: +9655556447 +4865556805 +4486555690 +4458655580 +4574865570 +5700086566 +6000009887 +8000000533 +6800000633 +5680000538 + +After step 60: +2533334200 +2743334640 +2264333458 +2225333337 +2225333338 +2287833333 +3854573455 +1854458611 +1175447111 +1115446111 + +After step 70: +8211111164 +0421111166 +0042111114 +0004211115 +0000211116 +0065611111 +0532351111 +7322235117 +5722223475 +4572222754 + +After step 80: +1755555697 +5965555609 +4486555680 +4458655580 +4570865570 +5700086566 +7000008666 +0000000990 +0000000800 +0000000000 + +After step 90: +7433333522 +2643333522 +2264333458 +2226433337 +2222433338 +2287833333 +2854573333 +4854458333 +3387779333 +3333333333 + +After step 100: +0397666866 +0749766918 +0053976933 +0004297822 +0004229892 +0053222877 +0532222966 +9322228966 +7922286866 +6789998766 + +``` + +After 100 steps, there have been a total of `*1656*` flashes. + +Given the starting energy levels of the dumbo octopuses in your cavern, simulate 100 steps. *How many total flashes are there after 100 steps?* + +Your puzzle answer was `1603`. + +\--- Part Two --- +---------- + +It seems like the individual flashes aren't bright enough to navigate. However, you might have a better option: the flashes seem to be *synchronizing*! + +In the example above, the first time all octopuses flash simultaneously is step `*195*`: + +``` +After step 193: +5877777777 +8877777777 +7777777777 +7777777777 +7777777777 +7777777777 +7777777777 +7777777777 +7777777777 +7777777777 + +After step 194: +6988888888 +9988888888 +8888888888 +8888888888 +8888888888 +8888888888 +8888888888 +8888888888 +8888888888 +8888888888 + +After step 195: +0000000000 +0000000000 +0000000000 +0000000000 +0000000000 +0000000000 +0000000000 +0000000000 +0000000000 +0000000000 + +``` + +If you can calculate the exact moments when the octopuses will all flash simultaneously, you should be able to navigate through the cavern. *What is the first step during which all octopuses flash?* + +Your puzzle answer was `222`. + +Both parts of this puzzle are complete! They provide two gold stars: \*\* + +At this point, you should [return to your Advent calendar](/2021) and try another puzzle. + +If you still want to see it, you can [get your puzzle input](11/input). \ No newline at end of file diff --git a/2021/day11_dumbo_octopus/src/lib.rs b/2021/day11_dumbo_octopus/src/lib.rs new file mode 100644 index 0000000..22ed152 --- /dev/null +++ b/2021/day11_dumbo_octopus/src/lib.rs @@ -0,0 +1,97 @@ +use core::fmt::Display; + +#[derive(Debug, PartialEq, Eq)] +pub enum ParseError { + ParseIntError(char), + LineMalformed(String), +} + +impl Display for ParseError { + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + match self { + Self::ParseIntError(c) => write!(f, "Unable to parse {c} into integer"), + Self::LineMalformed(v) => write!(f, "Line is malformed: {v}"), + } + } +} + +struct OctopusGrid { + grid: Vec>, + flashes: usize, +} + +impl TryFrom<&str> for OctopusGrid { + type Error = ParseError; + + fn try_from(value: &str) -> Result { + Ok(Self { + grid: value.lines() + .map(|line| line.chars().map(|c| c.to_digit(10).map(|d| d as u8).ok_or(Self::Error::ParseIntError(c))).collect::, _>>()) + .collect::, _>>()?, + flashes: 0, + }) + } +} +impl OctopusGrid { + fn neighbours(&self, (x, y): (usize, usize)) -> Vec<(usize, usize)> { + (0..3).flat_map(|dx| (0..3).filter(|dy| (dx != 1 || *dy != 1) && (1..=self.grid.len()).contains(&(x+dx)) && (1..=self.grid[0].len()).contains(&(y+dy))).map(|dy| (x+dx-1, y+dy-1)).collect::>()).collect() + } + + fn increase(&mut self, (x, y): (usize, usize)) { + self.grid[y][x] += 1; + if self.grid[y][x] == 10 { + self.flashes += 1; + self.neighbours((x, y)).iter().for_each(|n| self.increase(*n)); + } + } + + fn step(&mut self) { + (0..self.grid.len()).for_each(|y| (0..self.grid[y].len()).for_each(|x| self.increase((x, y)))); + self.grid.iter_mut().for_each(|row| row.iter_mut().for_each(|energy_level| { + if *energy_level > 9 { + *energy_level = 0; + } + })); + } +} + +pub fn run(input: &str) -> Result<(usize, usize), ParseError> { + let mut grid = OctopusGrid::try_from(input)?; + for _ in 1..=100 { + grid.step(); + } + let first = grid.flashes; + let mut second = 0; + let mut last_flashes = first; + for step in 101.. { + grid.step(); + if grid.flashes - last_flashes == 100 { + second = step; + break; + } + last_flashes = grid.flashes; + } + Ok((first, second)) +} + +#[cfg(test)] +mod tests { + use super::*; + use std::fs::read_to_string; + + fn read_file(name: &str) -> String { + read_to_string(name).expect(&format!("Unable to read file: {name}")[..]).trim().to_string() + } + + #[test] + fn test_sample() { + let sample_input = read_file("tests/sample_input"); + assert_eq!(run(&sample_input), Ok((1656, 195))); + } + + #[test] + fn test_challenge() { + let challenge_input = read_file("tests/challenge_input"); + assert_eq!(run(&challenge_input), Ok((1603, 222))); + } +} diff --git a/2021/day11_dumbo_octopus/tests/challenge_input b/2021/day11_dumbo_octopus/tests/challenge_input new file mode 100644 index 0000000..df77777 --- /dev/null +++ b/2021/day11_dumbo_octopus/tests/challenge_input @@ -0,0 +1,10 @@ +4112256372 +3143253712 +4516848631 +3783477137 +3746723582 +5861358884 +4843351774 +2316447621 +6643817745 +6366815868 diff --git a/2021/day11_dumbo_octopus/tests/sample_input b/2021/day11_dumbo_octopus/tests/sample_input new file mode 100644 index 0000000..03743f6 --- /dev/null +++ b/2021/day11_dumbo_octopus/tests/sample_input @@ -0,0 +1,10 @@ +5483143223 +2745854711 +5264556173 +6141336146 +6357385478 +4167524645 +2176841721 +6882881134 +4846848554 +5283751526