108 lines
1.9 KiB
Rust
108 lines
1.9 KiB
Rust
use std::collections::HashMap;
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use aoc::Result;
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const INPUT: &str = include_str!("../input/day02.txt");
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pub fn run() -> Result<()> {
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println!("part 1: {}", part1(INPUT)?);
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println!("part 2: {}", part2(INPUT)?);
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Ok(())
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}
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fn part1(input: &str) -> Result<u32> {
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let mut twice = 0;
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let mut thrice = 0;
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for line in input.lines() {
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let mut seen: HashMap<char, u32> = HashMap::new();
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for c in line.chars() {
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*seen.entry(c).or_default() += 1;
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}
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if seen.values().any(|x| *x == 2) {
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twice += 1;
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}
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if seen.values().any(|x| *x == 3) {
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thrice += 1;
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}
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}
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Ok(twice * thrice)
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}
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fn part2(input: &str) -> Result<String> {
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let lines = input.lines().collect::<Vec<&str>>();
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for i in 0..lines.len() {
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for j in (i + 1)..lines.len() {
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let different = lines[i]
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.chars()
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.zip(lines[j].chars())
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.filter(|tuple| tuple.0 != tuple.1)
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.count();
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if different == 1 {
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return Ok(common_letters(lines[i], lines[j]));
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}
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}
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}
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Ok("".into())
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}
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fn common_letters(a: &str, b: &str) -> String {
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a.chars()
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.zip(b.chars())
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.filter_map(|e| match e {
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(a, b) if a == b => Some(a),
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_ => None,
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})
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.collect()
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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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#[test]
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fn part1_provided() {
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let input = "abcdef
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bababc
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abbcde
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abcccd
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aabcdd
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abcdee
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ababab
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";
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assert_eq!(part1(input).unwrap(), 12);
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}
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#[test]
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fn part1_real() {
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assert_eq!(part1(INPUT).unwrap(), 5750);
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}
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#[test]
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fn part2_provided() {
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let input = "abcde
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fghij
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klmno
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pqrst
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fguij
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axcye
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wvxyz
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";
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assert_eq!(part2(input).unwrap(), "fgij");
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}
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#[test]
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fn part2_real() {
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assert_eq!(part2(INPUT).unwrap(), "tzyvunogzariwkpcbdewmjhxi");
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}
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}
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