80 lines
1.7 KiB
Rust
80 lines
1.7 KiB
Rust
|
use super::err;
|
||
|
|
use super::Result;
|
||
|
|
|
||
|
|
const INPUT: &str = include_str!("../input/day01.txt");
|
||
|
|
|
||
|
|
pub fn run() -> Result<()> {
|
||
|
|
println!("part 1: {}", part1(INPUT)?);
|
||
|
|
println!("part 2: {}", part2(INPUT)?);
|
||
|
|
|
||
|
|
Ok(())
|
||
|
|
}
|
||
|
|
|
||
|
|
fn part1(input: &str) -> Result<i64> {
|
||
|
|
Ok(input
|
||
|
|
.chars()
|
||
|
|
.filter_map(|c| match c {
|
||
|
|
'(' => Some(1),
|
||
|
|
')' => Some(-1),
|
||
|
|
_ => None,
|
||
|
|
})
|
||
|
|
.sum())
|
||
|
|
}
|
||
|
|
|
||
|
|
fn part2(input: &str) -> Result<usize> {
|
||
|
|
let mut sum = 0;
|
||
|
|
let mut res = 0;
|
||
|
|
|
||
|
|
for (i, c) in input.chars().enumerate() {
|
||
|
|
match c {
|
||
|
|
'(' => sum += 1,
|
||
|
|
')' => sum -= 1,
|
||
|
|
_ => return Err(err!("unidentified character in input: {}", c)),
|
||
|
|
};
|
||
|
|
|
||
|
|
if sum < 0 {
|
||
|
|
res = i + 1;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
match res {
|
||
|
|
0 => Err(err!("never reached the basement...")),
|
||
|
|
_ => Ok(res),
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
#[cfg(test)]
|
||
|
|
mod tests {
|
||
|
|
use super::*;
|
||
|
|
|
||
|
|
#[test]
|
||
|
|
fn part1_provided() {
|
||
|
|
assert_eq!(part1("(())").unwrap(), 0);
|
||
|
|
assert_eq!(part1("()()").unwrap(), 0);
|
||
|
|
assert_eq!(part1("(((").unwrap(), 3);
|
||
|
|
assert_eq!(part1("(()(()(").unwrap(), 3);
|
||
|
|
assert_eq!(part1("))(((((").unwrap(), 3);
|
||
|
|
assert_eq!(part1("())").unwrap(), -1);
|
||
|
|
assert_eq!(part1("))(").unwrap(), -1);
|
||
|
|
assert_eq!(part1(")))").unwrap(), -3);
|
||
|
|
assert_eq!(part1(")())())").unwrap(), -3);
|
||
|
|
}
|
||
|
|
|
||
|
|
#[test]
|
||
|
|
fn part1_real() {
|
||
|
|
assert_eq!(part1(INPUT).unwrap(), 74);
|
||
|
|
}
|
||
|
|
|
||
|
|
#[test]
|
||
|
|
fn part2_provided() {
|
||
|
|
assert_eq!(part2(")").unwrap(), 1);
|
||
|
|
assert_eq!(part2("()())").unwrap(), 5);
|
||
|
|
}
|
||
|
|
|
||
|
|
#[test]
|
||
|
|
fn part2_real() {
|
||
|
|
assert_eq!(part2(INPUT).unwrap(), 1795);
|
||
|
|
}
|
||
|
|
}
|