This commit is contained in:
Shadowfacts 2021-12-11 11:06:35 -05:00
parent a7ac4ac667
commit cf4b181695
5 changed files with 190 additions and 1 deletions

32
Cargo.lock generated
View File

@ -2,10 +2,20 @@
# It is not intended for manual editing.
version = 3
[[package]]
name = "ansi_term"
version = "0.12.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "d52a9bb7ec0cf484c551830a7ce27bd20d67eac647e1befb56b0be4ee39a55d2"
dependencies = [
"winapi",
]
[[package]]
name = "aoc21"
version = "0.1.0"
dependencies = [
"ansi_term",
"itertools",
]
@ -23,3 +33,25 @@ checksum = "a9a9d19fa1e79b6215ff29b9d6880b706147f16e9b1dbb1e4e5947b5b02bc5e3"
dependencies = [
"either",
]
[[package]]
name = "winapi"
version = "0.3.9"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
dependencies = [
"winapi-i686-pc-windows-gnu",
"winapi-x86_64-pc-windows-gnu",
]
[[package]]
name = "winapi-i686-pc-windows-gnu"
version = "0.4.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
[[package]]
name = "winapi-x86_64-pc-windows-gnu"
version = "0.4.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"

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@ -7,3 +7,4 @@ edition = "2021"
[dependencies]
itertools = "0.10.3"
ansi_term = "0.12.1"

10
input/day11.txt Normal file
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@ -0,0 +1,10 @@
1553421288
5255384882
1224315732
4258242274
1658564216
6872651182
5775552238
5622545172
8766672318
2178374835

145
src/day11.rs Normal file
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@ -0,0 +1,145 @@
use ansi_term::{Color, Style};
use std::collections::{HashSet, VecDeque};
use std::fmt::{Debug, Formatter};
use std::ops::RangeInclusive;
pub fn day11() {
// let input = r#"
// 11111
// 19991
// 19191
// 19991
// 11111
// "#;
// let grid: Grid<5> = input.into();
// dbg!(&grid);
// dbg!(&grid.step());
// dbg!(&grid.step().step());
// let input = r#"
// 5483143223
// 2745854711
// 5264556173
// 6141336146
// 6357385478
// 4167524645
// 2176841721
// 6882881134
// 4846848554
// 5283751526
// "#;
let input = include_str!("../input/day11.txt");
let mut grid: Grid<10> = input.into();
let mut total_flashes = 0;
println!("{:?}", grid);
for step in 0..100 {
let (new, flashed) = grid.step();
// println!("after step: {}, new grid: {:?}", step + 1, new);
grid = new;
total_flashes += flashed;
}
println!("grid: {:?}, total flashes: {}", grid, total_flashes);
let mut grid2: Grid<10> = input.into();
let mut step = 0;
loop {
step += 1;
let (new, flashed) = grid2.step();
grid2 = new;
if flashed == 100 {
break;
}
}
println!("grid: {:?}, after step: {}", grid2, step);
}
struct Grid<const N: usize> {
grid: [[u32; N]; N],
}
impl<const N: usize> Debug for Grid<N> {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
write!(f, "\n").expect("write");
for row in 0..N {
for col in 0..N {
let mut style = Style::new();
if self.grid[row][col] == 0 {
style = Color::White.bold();
}
write!(
f,
"{}{}{}",
style.prefix(),
self.grid[row][col],
style.suffix()
)
.expect("write");
}
write!(f, "\n").expect("write");
}
Ok(())
}
}
impl<const N: usize> From<&str> for Grid<N> {
fn from(s: &str) -> Self {
let mut grid = [[0; N]; N];
for (row, line) in s.trim().lines().enumerate() {
for (col, c) in line.trim().chars().enumerate() {
grid[row][col] = c.to_digit(10).unwrap();
}
}
Self { grid }
}
}
impl<const N: usize> Grid<N> {
fn step(&self) -> (Grid<N>, usize) {
let mut new_grid = [[0; N]; N];
// increment all
for row in 0..N {
for col in 0..N {
new_grid[row][col] = self.grid[row][col] + 1;
}
}
let mut to_flash = (0..N)
.flat_map(|row| (0..N).map(move |col| (row, col)))
.filter(|&(row, col)| new_grid[row][col] > 9)
.collect::<VecDeque<(usize, usize)>>();
let mut already_flashed: HashSet<(usize, usize)> = HashSet::new();
while let Some((row, col)) = to_flash.pop_front() {
if already_flashed.contains(&(row, col)) {
continue;
}
already_flashed.insert((row, col));
for r in adjacent(row, N) {
for c in adjacent(col, N) {
new_grid[r][c] += 1;
if new_grid[r][c] > 9 && !already_flashed.contains(&(r, c)) {
to_flash.push_back((r, c));
}
}
}
}
for &(row, col) in already_flashed.iter() {
new_grid[row][col] = 0;
}
(Self { grid: new_grid }, already_flashed.len())
}
}
fn adjacent(n: usize, max: usize) -> RangeInclusive<usize> {
let min = if n > 0 { n - 1 } else { n };
let max = if n < max - 1 { n + 1 } else { n };
min..=max
}

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@ -9,7 +9,8 @@ mod day07;
mod day08;
mod day09;
mod day10;
mod day11;
fn main() {
day10::day10();
day11::day11();
}