year2024/
day03.rs

1use utils::prelude::*;
2
3/// Extracting instructions from corrupted input.
4#[derive(Clone, Debug)]
5pub struct Day03 {
6    part1: u32,
7    part2: u32,
8}
9
10enum Instruction {
11    Mul(u32, u32),
12    Do,
13    Dont,
14}
15
16impl Day03 {
17    pub fn new(input: &str, _: InputType) -> Result<Self, InputError> {
18        let matches = parser::parse_tree!(
19            ("mul(", a @ parser::u32(), ",", b @ parser::u32(), ")") => Instruction::Mul(a, b),
20            ("don't()") => Instruction::Dont,
21            ("do()") => Instruction::Do,
22        )
23        .matches_iterator(input);
24
25        let (mut part1, mut part2) = (0, 0);
26        let mut enabled = true;
27        for instruction in matches {
28            match instruction {
29                Instruction::Mul(a, b) => {
30                    part1 += a * b;
31                    part2 += if enabled { a * b } else { 0 };
32                }
33                Instruction::Do => enabled = true,
34                Instruction::Dont => enabled = false,
35            }
36        }
37
38        Ok(Self { part1, part2 })
39    }
40
41    #[must_use]
42    pub fn part1(&self) -> u32 {
43        self.part1
44    }
45
46    #[must_use]
47    pub fn part2(&self) -> u32 {
48        self.part2
49    }
50}
51
52examples!(Day03 -> (u32, u32) [
53    {input: "xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))", part1: 161},
54    {input: "xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))", part2: 48},
55]);
year2024/day03.rs

year2024/
day03.rs
