80 lines
1.8 KiB
Rust
80 lines
1.8 KiB
Rust
#![warn(clippy::all, clippy::pedantic)]
|
|
|
|
use std::fs;
|
|
|
|
use nom::{
|
|
bytes::complete::tag,
|
|
character::complete::{self, newline},
|
|
multi::separated_list0,
|
|
sequence::separated_pair,
|
|
};
|
|
|
|
fn parse_range(input: &str) -> nom::IResult<&str, (i32, i32)> {
|
|
separated_pair(complete::i32, tag("-"), complete::i32)(input)
|
|
}
|
|
fn parse_line(input: &str) -> nom::IResult<&str, ((i32, i32), (i32, i32))> {
|
|
separated_pair(parse_range, tag(","), parse_range)(input)
|
|
}
|
|
fn process_input(input: &str) -> nom::IResult<&str, Vec<((i32, i32), (i32, i32))>> {
|
|
separated_list0(newline, parse_line)(input)
|
|
}
|
|
|
|
fn part1(input: &str) -> String {
|
|
do_part(input, |(a, b)| {
|
|
i32::from((a.0 <= b.0 && a.1 >= b.1) || (a.0 >= b.0 && a.1 <= b.1))
|
|
})
|
|
}
|
|
fn part2(input: &str) -> String {
|
|
do_part(input, |(a, b)| {
|
|
i32::from(
|
|
(a.0 >= b.0 && a.0 <= b.1)
|
|
|| (a.1 >= b.0 && a.1 <= b.1)
|
|
|| (b.0 >= a.0 && b.0 <= a.1)
|
|
|| (b.1 >= a.0 && b.1 <= a.1),
|
|
)
|
|
})
|
|
}
|
|
|
|
fn do_part(input: &str, f: impl Fn((&(i32, i32), &(i32, i32))) -> i32) -> String {
|
|
let (_, ranges) = process_input(input).unwrap();
|
|
ranges
|
|
.iter()
|
|
.map(|(a, b)| f((a, b)))
|
|
.fold(0, |mut acc: i32, x: i32| {
|
|
acc += x;
|
|
acc
|
|
})
|
|
.to_string()
|
|
}
|
|
fn main() -> std::io::Result<()> {
|
|
//Read in file
|
|
let file = fs::read_to_string("input")?;
|
|
|
|
println!("Part 1: {}", part1(&file));
|
|
println!("Part 2: {}", part2(&file));
|
|
|
|
Ok(())
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod test {
|
|
use super::*;
|
|
|
|
const INPUT: &str = "2-4,6-8
|
|
2-3,4-5
|
|
5-7,7-9
|
|
2-8,3-7
|
|
6-6,4-6
|
|
2-6,4-8";
|
|
|
|
#[test]
|
|
fn part1_works() {
|
|
assert_eq!(part1(INPUT), "2")
|
|
}
|
|
|
|
#[test]
|
|
fn part2_works() {
|
|
assert_eq!(part2(INPUT), "4")
|
|
}
|
|
}
|