advent-of-code/2022/rust/src/day9.rs

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2022-12-09 10:44:26 -06:00
mod common;
use std::collections::HashSet;
type Input = Vec<(char, i32)>;
type Answer = usize;
fn processed_input(input: &str) -> Input {
input
.lines()
.map(|l| {
let mut args = l.split(' ');
(
args.next().unwrap().chars().next().unwrap(),
args.next().unwrap().parse::<i32>().unwrap(),
)
})
.collect()
}
fn part1(input: &Input) -> Answer {
let mut p: HashSet<(i32, i32)> = HashSet::new();
let mut h: (i32, i32) = (0, 0);
let mut t: (i32, i32) = (0, 0);
let mut m = |x, y, n| {
for _ in 0..n {
h.0 += x;
h.1 += y;
if t.0.abs_diff(h.0) > 1 && t.1.abs_diff(h.1) > 1 {
t.0 += (h.0 - t.0) / 2;
t.1 += (h.1 - t.1) / 2;
} else if t.0.abs_diff(h.0) > 1 {
t.0 += (h.0 - t.0) / 2;
t.1 = h.1;
} else if t.1.abs_diff(h.1) > 1 {
t.1 += (h.1 - t.1) / 2;
t.0 = h.0;
}
p.insert(t);
println!("h: ({}, {}), t: ({}, {})", h.0, h.1, t.0, t.1);
}
};
for i in input {
println!("{:?}", i);
match i.0 {
'L' => m(-1, 0, i.1),
'R' => m(1, 0, i.1),
'U' => m(0, -1, i.1),
'D' => m(0, 1, i.1),
_ => (),
}
}
p.len()
}
fn part2(input: &Input) -> Answer {
0
}
fn main() {
let input_text = common::day_input(9);
eprintln!("{}\n\nAbove is your input file.\n\n", input_text);
let input = processed_input(&input_text);
common::show_answers(&part1(&input), &part2(&input))
}
#[cfg(test)]
mod tests {
use super::*;
const TEST_INPUT: &str = "R 4
U 4
L 3
D 1
R 4
D 1
L 5
R 2";
#[test]
fn test() {
let input = processed_input(TEST_INPUT);
assert_eq!(part1(&input), 13);
assert_eq!(part2(&input), 0);
}
}