day(06): add initial solution

Signed-off-by: Matej Focko <mfocko@redhat.com>

samples/day06.txt

@@ -0,0 +1 @@
+mjqjpqmgbljsphdztnvjfqwrcgsmlb

src/bin/day06.rs

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+use std::collections::HashSet;
+use std::str::FromStr;
+
+use aoc_2022::*;
+
+use color_eyre::eyre::{Report, Result};
+use itertools::Itertools;
+use tracing::*;
+use tracing_subscriber::EnvFilter;
+
+type Input = String;
+type Output = usize;
+
+fn part_1(input: &str) -> Output {
+    let chars: Vec<_> = input.chars().collect();
+
+    chars
+        .windows(4)
+        .enumerate()
+        .map(|(i, chars)| (i, chars.iter().collect::<HashSet<_>>()))
+        .find_or_first(|(_, s)| s.len() == 4)
+        .unwrap()
+        .0
+        + 4
+}
+
+fn part_2(input: &Input) -> Output {
+    let chars: Vec<_> = input.chars().collect();
+
+    chars
+        .windows(14)
+        .enumerate()
+        .map(|(i, chars)| (i, chars.iter().collect::<HashSet<_>>()))
+        .find_or_first(|(_, s)| s.len() == 14)
+        .unwrap()
+        .0
+        + 14
+}
+
+fn parse_input(pathname: &str) -> Input {
+    file_to_string(pathname)
+}
+
+fn main() -> Result<()> {
+    tracing_subscriber::fmt()
+        .with_env_filter(EnvFilter::from_default_env())
+        .with_target(false)
+        .with_file(true)
+        .with_line_number(true)
+        .without_time()
+        .compact()
+        .init();
+    color_eyre::install()?;
+
+    let input = parse_input("inputs/day06.txt");
+
+    info!("Part 1: {}", part_1(&input));
+    info!("Part 2: {}", part_2(&input));
+
+    Ok(())
+}
+
+#[cfg(test)]
+mod day_06 {
+    use super::*;
+
+    #[test]
+    fn test_part_1() {
+        let sample = parse_input("samples/day06.txt");
+        assert_eq!(part_1(&sample), 7);
+    }
+
+    #[test]
+    fn test_part_1_example_1() {
+        assert_eq!(part_1(&"bvwbjplbgvbhsrlpgdmjqwftvncz".to_string()), 5);
+    }
+
+    #[test]
+    fn test_part_1_example_2() {
+        assert_eq!(part_1(&"nppdvjthqldpwncqszvftbrmjlhg".to_string()), 6);
+    }
+
+    #[test]
+    fn test_part_1_example_3() {
+        assert_eq!(part_1(&"nznrnfrfntjfmvfwmzdfjlvtqnbhcprsg".to_string()), 10);
+    }
+
+    #[test]
+    fn test_part_1_example_4() {
+        assert_eq!(part_1(&"zcfzfwzzqfrljwzlrfnpqdbhtmscgvjw".to_string()), 11);
+    }
+
+    #[test]
+    fn test_part_2() {
+        let sample = parse_input("samples/day06.txt");
+        assert_eq!(part_2(&sample), 19);
+    }
+
+    #[test]
+    fn test_part_2_example_1() {
+        assert_eq!(part_2(&"bvwbjplbgvbhsrlpgdmjqwftvncz".to_string()), 23);
+    }
+
+    #[test]
+    fn test_part_2_example_2() {
+        assert_eq!(part_2(&"nppdvjthqldpwncqszvftbrmjlhg".to_string()), 23);
+    }
+
+    #[test]
+    fn test_part_2_example_3() {
+        assert_eq!(part_2(&"nznrnfrfntjfmvfwmzdfjlvtqnbhcprsg".to_string()), 29);
+    }
+
+    #[test]
+    fn test_part_2_example_4() {
+        assert_eq!(part_2(&"zcfzfwzzqfrljwzlrfnpqdbhtmscgvjw".to_string()), 26);
+    }
+}