59 lines
1.4 KiB
Rust
59 lines
1.4 KiB
Rust
use aoc::*;
|
|
use regex::{Captures, Regex};
|
|
|
|
const INPUT: &str = include_str!("../../input/03");
|
|
|
|
fn main() {
|
|
assert_example!(part1, "03-test", 161);
|
|
println!("Part 1: {}", part1(INPUT));
|
|
assert_example!(part2, "03-test", 48);
|
|
println!("Part 2: {}", part2(INPUT));
|
|
}
|
|
|
|
fn part1(input: &str) -> i64 {
|
|
parse(input)
|
|
.into_iter()
|
|
.filter_map(|i| match i {
|
|
Instruction::Mul(a, b) => Some(a * b),
|
|
Instruction::Do | Instruction::Dont => None,
|
|
})
|
|
.sum()
|
|
}
|
|
|
|
fn part2(input: &str) -> i64 {
|
|
let mut sum = 0;
|
|
let mut enabled = true;
|
|
for instruction in parse(input) {
|
|
match instruction {
|
|
Instruction::Do => enabled = true,
|
|
Instruction::Dont => enabled = false,
|
|
Instruction::Mul(a, b) if enabled => {
|
|
sum += a * b;
|
|
}
|
|
Instruction::Mul(_, _) => (),
|
|
}
|
|
}
|
|
sum
|
|
}
|
|
|
|
fn parse(input: &str) -> Vec<Instruction> {
|
|
let regex = Regex::new(r#"(mul\((\d+),(\d+)\)|don't\(\)|do\(\))"#).unwrap();
|
|
regex.captures_iter(input).map(parse_instruction).collect()
|
|
}
|
|
|
|
fn parse_instruction(c: Captures) -> Instruction {
|
|
if c[0].starts_with("mul") {
|
|
let (a, b) = (c[2].parse().unwrap(), c[3].parse().unwrap());
|
|
Instruction::Mul(a, b)
|
|
} else if c[0].starts_with("don") {
|
|
Instruction::Dont
|
|
} else {
|
|
Instruction::Do
|
|
}
|
|
}
|
|
|
|
enum Instruction {
|
|
Do,
|
|
Dont,
|
|
Mul(i64, i64),
|
|
}
|