aoc2015/src/bin/06.rs

126 lines
3.0 KiB
Rust

use lazy_static::lazy_static;
use regex::Regex;
use Instruction::*;
#[derive(Debug)]
struct Point {
x: usize,
y: usize,
}
impl FromIterator<usize> for Point {
fn from_iter<T: IntoIterator<Item = usize>>(iter: T) -> Self {
let mut it = iter.into_iter();
Point {
x: it.next().unwrap(),
y: it.next().unwrap(),
}
}
}
#[derive(Debug)]
enum Instruction {
On,
Off,
Toggle,
}
#[derive(Debug)]
struct Command {
instruction: Instruction,
from: Point,
to: Point,
}
impl From<&str> for Command {
fn from(value: &str) -> Self {
lazy_static! {
static ref RE: Regex = Regex::new(
r"(turn on|turn off|toggle) (\d{1,3},\d{1,3}) through (\d{1,3},\d{1, 3})"
)
.unwrap();
}
let capture = RE.captures(value).unwrap();
let instruction = match capture[1].as_ref() {
"turn on" => On,
"turn off" => Off,
"toggle" => Toggle,
_ => unreachable!(),
};
let from: Point = capture[2].split(',').map(|x| x.parse().unwrap()).collect();
let to: Point = capture[3].split(',').map(|x| x.parse().unwrap()).collect();
Command {
instruction,
from,
to,
}
}
}
pub fn part_one(input: &str) -> Option<u32> {
let mut a = vec![[0; 1000]; 1000];
for line in input.trim().split('\n') {
let Command {
instruction,
from,
to,
} = Command::from(line);
for x in a.iter_mut().take(to.x + 1).skip(from.x) {
for y in x.iter_mut().take(to.y + 1).skip(from.y) {
match instruction {
On => *y = 1,
Off => *y = 0,
Toggle => *y = 1 - *y,
}
}
}
}
Some(a.iter().map(|x| -> u32 { x.iter().sum() }).sum())
}
pub fn part_two(input: &str) -> Option<u32> {
let mut a = vec![[0; 1000]; 1000];
for line in input.trim().split('\n') {
let Command {
instruction,
from,
to,
} = Command::from(line);
for x in a.iter_mut().take(to.x + 1).skip(from.x) {
for y in x.iter_mut().take(to.y + 1).skip(from.y) {
match instruction {
On => *y += 1,
Toggle => *y += 2,
Off if y > &mut 0 => *y -= 1,
_ => (),
}
}
}
}
Some(a.iter().map(|x| -> u32 { x.iter().sum() }).sum())
}
fn main() {
let input = &aoc::read_file("inputs", 6);
aoc::solve!(1, part_one, input);
aoc::solve!(2, part_two, input);
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_part_one() {
let input = aoc::read_file("test_inputs", 6);
assert_eq!(part_one(&input), Some(998996));
}
#[test]
fn test_part_two() {
let input = aoc::read_file("test_inputs", 6);
assert_eq!(part_two(&input), Some(1001996));
}
}