64 lines
1.2 KiB
Rust
64 lines
1.2 KiB
Rust
use itertools::Itertools;
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use std::fs::read_to_string;
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pub fn day_main() {
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let input = read_to_string("input/day01.txt").unwrap();
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println!(" part1: {}", part1(&input));
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println!(" part2: {}", part2(&input));
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}
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type Int = i32;
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fn part1(input: &str) -> Int {
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let (mut l, mut r) = make_lists(input);
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l.sort();
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r.sort();
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l.into_iter().zip(r).map(|(l, r)| (l - r).abs()).sum()
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}
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fn part2(input: &str) -> Int {
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let (l, r) = make_lists(input);
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l.iter()
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.map(|l| r.iter().filter(|r| *r == l).count() as Int * l)
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.sum()
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}
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fn make_lists(input: &str) -> (Vec<Int>, Vec<Int>) {
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input
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.trim()
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.lines()
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.map(|line| line.split_ascii_whitespace().collect_tuple().unwrap())
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.map(|(x, y)| (x.parse::<Int>().unwrap(), y.parse::<Int>().unwrap()))
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.fold((vec![], vec![]), |(mut v1, mut v2), (a, b)| {
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v1.push(a);
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v2.push(b);
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(v1, v2)
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})
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}
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#[cfg(test)]
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mod test {
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use super::{part1, part2};
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const TEST_INPUT: &str = r"
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3 4
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4 3
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2 5
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1 3
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3 9
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3 3
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";
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#[test]
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fn test1() {
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assert_eq!(part1(TEST_INPUT), 11);
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}
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#[test]
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fn test2() {
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assert_eq!(part2(TEST_INPUT), 31);
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}
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}
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