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advent-of-rust-2024/src/day03.rs
2024-12-03 06:25:49 +01:00

89 lines
2.2 KiB
Rust

use itertools::Itertools;
use std::fs::read_to_string;
pub fn day_main() {
let input = read_to_string("input/day03.txt").unwrap();
let input = input.trim();
println!("part1: {}", part1(input));
println!("part2: {}", part2(input));
}
type RiddleResult = i64;
fn part1(input: &str) -> RiddleResult {
let r = regex::Regex::new(r"mul\((\d{1,3}),(\d{1,3})\)").unwrap();
r.captures_iter(input)
.map(|c| {
let a: i64 = c.get(1).unwrap().as_str().parse().unwrap();
let b: i64 = c.get(2).unwrap().as_str().parse().unwrap();
a * b
})
.sum()
}
enum Statement {
Enable,
Disable,
Number(i64),
}
fn part2(input: &str) -> RiddleResult {
let r = regex::Regex::new(r"do\(\)|don't\(\)|mul\((\d{1,3}),(\d{1,3})\)").unwrap();
let statements = r
.captures_iter(input)
.map(|c| {
let s = c.get(0).unwrap().as_str();
match s {
"do()" => Statement::Enable,
"don't()" => Statement::Disable,
_ => {
let a: i64 = c.get(1).unwrap().as_str().parse().unwrap();
let b: i64 = c.get(2).unwrap().as_str().parse().unwrap();
Statement::Number(a * b)
}
}
})
.collect_vec();
let mut enabled = true;
let mut result = 0;
for f in statements {
match f {
Statement::Enable => {
enabled = true;
}
Statement::Disable => {
enabled = false;
}
Statement::Number(i) => {
if enabled {
result += i
}
}
}
}
result
}
#[cfg(test)]
mod test {
use super::{part1, part2};
const TEST_INPUT: &str =
r"xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))";
const TEST_INPUT2: &str =
r"xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))";
#[test]
fn test1() {
assert_eq!(part1(TEST_INPUT), 161);
}
#[test]
fn test2() {
assert_eq!(part2(TEST_INPUT2), 48);
}
}