69 lines
1.7 KiB
Rust
69 lines
1.7 KiB
Rust
#![feature(test)]
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extern crate test;
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use aoc2021::common::*;
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const DAY: usize = 2;
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type Parsed = Vec<Movement>;
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#[derive(Debug, Clone, Copy)]
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enum Movement {
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Up(i64),
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Down(i64),
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Forward(i64),
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}
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fn parse_input(raw: &str) -> Parsed {
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raw.lines()
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.filter_map(|l| l.split_once(' '))
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.map(|(dir, dist)| match dir {
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"up" => Movement::Up(dist.parse().unwrap()),
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"down" => Movement::Down(dist.parse().unwrap()),
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"forward" => Movement::Forward(dist.parse().unwrap()),
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_ => unreachable!(),
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})
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.collect()
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}
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fn part1(parsed: &Parsed) -> i64 {
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let (depth, distance) = parsed.iter().fold((0, 0), |(depth, distance), &mov| match mov {
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Movement::Up(x) => (depth - x, distance),
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Movement::Down(x) => (depth + x, distance),
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Movement::Forward(x) => (depth, distance + x),
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});
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depth * distance
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}
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fn part2(parsed: &Parsed) -> i64 {
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let (depth, distance, _) = parsed.iter().fold((0, 0, 0), |(depth, distance, aim), &mov| match mov {
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Movement::Up(x) => (depth, distance, aim - x),
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Movement::Down(x) => (depth, distance, aim + x),
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Movement::Forward(x) => (depth + aim * x, distance + x, aim),
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});
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depth * distance
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}
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fn main() {
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let input = parse_input(&read_file(DAY));
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println!("Part 1: {}", part1(&input));
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println!("Part 2: {}", part2(&input));
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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use aoc2021::*;
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const TEST_INPUT: &str = "forward 5
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down 5
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forward 8
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up 3
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down 8
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forward 2";
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test!(part1() == 150);
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test!(part2() == 900);
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bench!(part1() == 1698735);
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bench!(part2() == 1594785890);
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bench_input!(len == 1000);
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}
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