aoc/AoC_2025/src/days/day03.rs
2025-12-04 12:24:05 +01:00

53 lines
1.4 KiB
Rust

use crate::days::Solution;
pub struct Day03;
impl Solution for Day03 {
type Input = Vec<Vec<u32>>;
fn parse(&self, data: &str) -> Self::Input {
data.split("\n")
.filter(|s| !s.is_empty())
.map(|s| s.chars().map(|c| c.to_digit(10).unwrap_or(0)).collect())
.collect()
}
fn part1(&self, input: &Self::Input) -> usize {
input
.iter()
.map(|l| {
let (i1, m1) = max(&l[..l.len() - 1]);
let (_, m2) = max(&l[i1 + 1..]);
10 * m1 + m2
})
.sum::<u32>() as usize
}
fn part2(&self, input: &Self::Input) -> usize {
println!("Part2");
input
.iter()
.map(|l| {
(0..12)
.rfold((0, 0), |(start_index, joltage), n| {
let (i, m) = max(&l[start_index..l.len() - n]);
(
start_index + i + 1,
usize::pow(10, n as u32) * m as usize + joltage,
)
})
.1
})
.sum()
}
}
fn max(l: &[u32]) -> (usize, u32) {
let x = l.iter().enumerate().fold(
(0, 0),
|(index_m, m), (i, &x)| if x > m { (i, x) } else { (index_m, m) },
);
println!("Max of {:?} is {:?}", l, x);
x
}