Solution for day5

2024/data/day6.txt

@@ -0,0 +1,130 @@
+.........#...#................................#.........#............#.....#....#.....................................#...........
+............................................................................................#...............#.......#.............
+....#.......#......................................#.........................#..#....#....#.........#.............................
+............##..#............#........................#........#........#.......#...........................#................#....
+..................................#.............#....#..........................#................#..#....##........#..............
+..................##.#...#....#...................##.....#.................#......##.....................##............#..........
+..........#..................................#....................................................................................
+......#...........#.......................................#........#........................#........#............................
+..................#................................#........................#.............................#.......................
+.............#............................................................................................##.................#....
+........#..............................................................................................#..............#.#.......#.
+..#...........#..............#..............#..#.....#.......#......#.......................#....#...................##..........#
+..............##................................#..............##....................#...#........................................
+......................#.................#.......#.......##.##....................................#................................
+...........#...#.#..................#...#.....................................................................#...................
+.....#....#...#..............................................................................................#.......#............
+...............................#...........#.#.............#.........#.....................................#.#....................
+........#...........#.......#............................#.....#.............................#.........................#..........
+...................................................#...........#.....#..#....#.............#.....#..#..#.............#............
+..............#.........#..#..........#.#.......................#...................................#.............................
+..#.............#..#..#.#...........#...................................................#...........................#...........#.
+........##....##..........................................................................#.......................................
+.......................................................#.......#.............................#...................#........#.......
+#.....#.#......#...............................................................#..........#........#..............................
+.#.#............#..............#..........................#.#.....................................................#...............
+.................#...#........#....#.....#...#...................................#....#.................#..........#...#.#...#....
+...#..##........................#..#..................................................................................#.......#...
+.................#...#.#..................................................#..#........#.................#...................#.....
+.......................#.......#....................#......................................#...............................#......
+...............................................................................................................................#..
+...........##............................#....................#...................................................................
+..#........................................#..#.............................#............................#........................
+..#.#....#..................................#...................................................................................#.
+.................#...#...............#..........#..............................#...#..............................#.#..#..........
+............#..........#..........#...................................#.....#....................#................##.............#
+....#...........#.......#......................................#........................................#........#......#...#.....
+.............#.....#...................#....#.....................................................................................
+.....................#.................................#.#...................#.......#.#...............#..........................
+........#..............#.......#.............#...........................................................#........#..............#
+............#............................................#.......##................#..............................................
+...............................#..................................................................................................
+#....................#......#.......................#..........#.........................#................#...............#..#...#
+..................................................#.....#...........#...#..#......#...........................#...................
+............#......................#.....#.........#....................................................................#....#....
+.......#...................#...#...........................#.......#......#......................................#.....#..........
+.................................................#.............#....................................#.............................
+......#.................#.............................................................................#..##.......................
+....#..............................................#..............#..........#.......#....#............................#..........
+........#....#............#....#.................#........................................................#.....#.................
+..#......................#.......................................................#................................................
+.#.....................#..........................................................#.............................#.................
+.............#..............#.#.....#.........................................#...............................#.........#.........
+.............................................................................#............................#....#...#..............
+#.#.#...................................................................#...........................................#.........#...
+..................................................#.#............#..#...#..............#.....#....................................
+......#..................................#............................##.........................................#................
+..#....................................#............#.........#.........#...........#.....#..............................#........
+......................................#.............#..................#.................#..........................##............
+...............#.#........#.......................#..........#...............................#.............................#.#....
+.................#....................................................................................#...........................
+#...............................................#.#........#...#...................#............#.................#......#.#......
+................#........................#......#.............................................#.#..............#....#.............
+.......#..........#..........................#......#.............................................................................
+....#.......#.................................................#..............#...........#.....#............#............#........
+.....................#...................................#...............................................................#........
+#..........................#..#...........................................#...............#............#............#.............
+.............................#...................................#...#.......................................#......#.............
+............#........#.................................................#.................#...................#....................
+.........................................#................#.....................................#.................................
+...........................................................................................#.....................#................
+.....................#.........#..#.#......................................................#........#.............................
+..#......#.........#.#...................................................#......................#.................................
+.#...........#.........................................................................................#.....................#....
+..........#....##.#..#..........#........#.#.................................#.....................#..............................
+.....#........#.......#....#...........#...................#...............#..#....#..............................#..............#
+.......#..............................#............#.................................................#........#................#..
+...............................#..............................................#...................................................
+#..............................................................#.........................................................#........
+.......#....................................................#..............................#..................#..........##.......
+.......................................#...............................................^.............#............................
+..#...........#.........#............................#...................................#.#.......###.....#......................
+........#............................................................................................................#............
+...#...#...........#.................................................................#...#.......#........#.......................
+...............#.....................................#..........#.......#.#.....#.#..................#............................
+.....#..#..............#.#.......................#.................................................................#..............
+#.....#.........................................#..##....#..........................#...................#..#......#........#......
+...................##................#..#......................................#.....#............................................
+....#...............................................................................................#...........................#.
+....#..........#....#........................#....................................................................................
+..................#.....................................................#.....................................#...................
+...........................#......#.......................................................................#..............#........
+...............#....................#...#...#.......#................#.......#.......#............................................
+#.....##......#.............................................#...#.................................#.................#....#..##..#.
+..........#.......................................#..................................#...#....#......................#............
+......#................#.#........#....#......##.........#........................................#...............................
+......#...#............#...#.........................................................#....#.....#..............#..................
+.........................#...............#........#...#......#....................................................#..#.#..........
+...##............#........#.#.........................#.............................#............#..............#.................
+.......#.........#..............................#...................................#.......................#.#...................
+#..........#.............#..............................................#.....................................................#...
+........#..#...#.....................................#............................................................................
+..................#...............................#..........................................#.............#..............#..#....
+....#.#..#...#............................#..............#...#..........#......#....#.....................#..........#......#.....
+................#..............#........................#......#..............#.......................##..........................
+..........#.....#.............................................#.......#...........................................#...............
+.........#....#........#............#...............#.............................................................................
+...........#..#..........#..............#..........#......#.......................................................................
+..........#....................#........................................#.....#..................#..#.#..#...#.....#..............
+........#...........#...#..................##.........#......................#...#............#......................#............
+...................................................#........................#.....#.............#.................................
+........#................#..........................#.#...#......#........................................#.......................
+.............#.........................................##....................#...................#.#..................#...........
+..................#.............................................#...............................................................#.
+.....#............#................#..............................#...##....#...#.................................................
+#.......................###........#..............#.....#.............#...............#.............#......................#......
+...........#.............................#........................#.........................................................#.....
+............#.....#.....#...#....#........#...............................#.....................#..................#....#.........
+...............#.#..................................#.................#.#......#...........#...#................#.................
+.....#............................................#.....#...............#.....#.............#.......#..........#..................
+.....................................#................................................#.........#..#..............................
+.....................#...............................................#.#...........#........#.....................................
+.............................................#....................#.............#......................#..........................
+......................................#.........#.........................##........#................#...............#............
+........................#.....#.....................................#....#........#......#..............#.......##...........#.#..
+....................#........................................#.........#.........#......#....#............#...........#...........
+...........##......#...........#................#.......##.....#........#.........#...........................................#...
+...................#...#....#.............#..#......................................................#............#................
+....#.........................#....#..................#..............#.............#...................................#..........
+..................................#.......#.....................#.................................................................
+.............................................#......#.......................................................#.....................

2024/src/day5.rs

@@ -0,0 +1,224 @@
+use std::collections::{HashMap, HashSet};
+
+use nom::{
+    bytes::complete::{tag, take_while},
+    character::{
+        complete::{digit1, line_ending},
+        is_digit,
+    },
+    multi::{many1, separated_list1},
+    sequence::terminated,
+    IResult,
+};
+
+const INPUT: &'static str = include_str!("../data/day5.txt");
+
+pub fn day5a() -> String {
+    let (deps, manuals) = parse_input(INPUT);
+    format!("{}", part_a(deps, manuals))
+}
+
+pub fn day5b() -> String {
+    let (deps, manuals) = parse_input(INPUT);
+    format!("{}", part_b(deps, manuals))
+}
+
+fn part_a(deps: Dependencies, manuals: Vec<Manual>) -> i32 {
+    manuals
+        .into_iter()
+        .filter(|manual| is_safe(&deps, manual))
+        .map(|manual| middle_page(&manual))
+        .fold(0, |acc, page_num| acc + page_num)
+}
+
+fn part_b(deps: Dependencies, manuals: Vec<Manual>) -> i32 {
+    println!("{:?}", deps);
+    manuals
+        .into_iter()
+        .filter(|manual| !is_safe(&deps, manual))
+        .map(|manual| fix_manual(&deps, &manual))
+        .map(|manual| middle_page(&manual))
+        .fold(0, |acc, page_num| acc + page_num)
+}
+
+fn fix_manual(deps: &Dependencies, manual: &Manual) -> Manual {
+    let pages_present: HashSet<i32> = manual.iter().cloned().collect();
+    let mut result = vec![];
+
+    for page in pages_present.iter() {
+        handle(*page, &mut result, &pages_present, deps);
+    }
+
+    println!("{:?}", result);
+    result
+}
+
+fn handle(page: i32, result: &mut Vec<i32>, present: &HashSet<i32>, deps: &Dependencies) {
+    let empty_deps: HashSet<i32> = HashSet::new();
+
+    for page_dep in deps.get(&page).unwrap_or(&empty_deps) {
+        if present.contains(page_dep) && !result.contains(page_dep) {
+            handle(*page_dep, result, present, deps);
+        }
+    }
+
+    if !result.contains(&page) {
+        result.push(page);
+    }
+}
+
+fn middle_page(manual: &Manual) -> i32 {
+    let center_idx = manual.len() / 2;
+    manual[center_idx]
+}
+
+fn is_safe(deps: &Dependencies, manual: &Manual) -> bool {
+    let values_present: HashSet<i32> = manual.iter().cloned().collect();
+    let mut values_counted: HashSet<i32> = HashSet::new();
+    let empty_deps: HashSet<i32> = HashSet::new();
+
+    for page in manual.iter() {
+        for page_dep in deps.get(page).unwrap_or(&empty_deps).iter() {
+            if values_present.contains(page_dep) {
+                if !values_counted.contains(page_dep) {
+                    return false;
+                }
+            }
+        }
+        values_counted.insert(*page);
+    }
+
+    true
+}
+
+type Dependencies = HashMap<i32, HashSet<i32>>;
+type Manual = Vec<i32>;
+
+fn parse_input(input: &str) -> (Dependencies, Vec<Manual>) {
+    let (_, data) = parse_input_(input).unwrap();
+    data
+}
+
+fn parse_input_(input: &str) -> IResult<&str, (Dependencies, Vec<Manual>)> {
+    let (input, dep_list) = many1(parse_dependency)(input)?;
+    let (input, _) = line_ending(input)?;
+    let (input, manuals) = many1(terminated(parse_manual, line_ending))(input)?;
+
+    let mut deps = HashMap::new();
+    for (predecessor, successor) in dep_list.into_iter() {
+        deps.entry(successor)
+            .and_modify(|preds: &mut HashSet<i32>| {
+                preds.insert(predecessor);
+            })
+            .or_insert(vec![predecessor].into_iter().collect::<HashSet<i32>>());
+    }
+    Ok((input, (deps, manuals)))
+}
+
+fn parse_dependency(input: &str) -> IResult<&str, (i32, i32)> {
+    let (input, pred) = parse_page_number(input)?;
+    let (input, _) = tag("|")(input)?;
+    let (input, succ) = parse_page_number(input)?;
+    let (input, _) = line_ending(input)?;
+    Ok((input, (pred, succ)))
+}
+
+fn parse_manual(input: &str) -> IResult<&str, Manual> {
+    separated_list1(tag(","), parse_page_number)(input)
+}
+
+fn parse_page_number(input: &str) -> IResult<&str, i32> {
+    let (input, digits) = digit1(input)?;
+    let page_num = digits.parse::<i32>().unwrap();
+    Ok((input, page_num))
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    const TEST_DATA: &'static str = "47|53
+97|13
+97|61
+97|47
+75|29
+61|13
+75|53
+29|13
+97|29
+53|29
+61|53
+97|53
+61|29
+47|13
+75|47
+97|75
+47|61
+75|61
+47|29
+75|13
+53|13
+
+75,47,61,53,29
+97,61,53,29,13
+75,29,13
+75,97,47,61,53
+61,13,29
+97,13,75,29,47
+";
+
+    #[test]
+    fn it_solves_part_a() {
+        let (deps, manuals) = parse_input(TEST_DATA);
+        assert_eq!(part_a(deps, manuals), 143);
+        let (deps, manuals) = parse_input(INPUT);
+        assert_eq!(part_a(deps, manuals), 6242);
+    }
+
+    #[test]
+    fn it_solves_part_b() {
+        let (deps, manuals) = parse_input(TEST_DATA);
+        assert_eq!(part_b(deps, manuals), 123);
+        let (deps, manuals) = parse_input(INPUT);
+        assert_eq!(part_b(deps, manuals), 5169);
+    }
+
+    /*
+    #[test]
+    fn it_finds_correct_manuals() {
+        let (deps, manuals) = parse_input(TEST_DATA);
+        let safe = safe_manuals(deps, manuals);
+        assert_eq!(safe.len(), 3);
+        assert_eq!(safe[0], vec![75, 47, 61, 53, 29]);
+        assert_eq!(safe[1], vec![97, 61, 53, 29, 13]);
+        assert_eq!(safe[2], vec![75, 29, 13]);
+    }
+    */
+
+    #[test]
+    fn it_checks_manuals() {
+        let (deps, manuals) = parse_input(TEST_DATA);
+        assert!(is_safe(&deps, &manuals[0]));
+        assert!(is_safe(&deps, &manuals[1]));
+        assert!(is_safe(&deps, &manuals[2]));
+        assert!(!is_safe(&deps, &manuals[3]));
+        assert!(!is_safe(&deps, &manuals[4]));
+        assert!(!is_safe(&deps, &manuals[5]));
+    }
+
+    #[test]
+    fn it_finds_center_values() {
+        let (deps, manuals) = parse_input(TEST_DATA);
+        assert_eq!(middle_page(&manuals[0]), 61);
+        assert_eq!(middle_page(&manuals[1]), 53);
+        assert_eq!(middle_page(&manuals[2]), 29);
+    }
+
+    #[test]
+    fn it_fixes_manuals() {
+        let (deps, manuals) = parse_input(TEST_DATA);
+        assert_eq!(fix_manual(&deps, &manuals[3]), vec![97, 75, 47, 61, 53]);
+        assert_eq!(fix_manual(&deps, &manuals[4]), vec![61, 29, 13]);
+        assert_eq!(fix_manual(&deps, &manuals[5]), vec![97, 75, 47, 29, 13]);
+    }
+}

2024/src/day6.rs

@@ -0,0 +1,26 @@
+const INPUT: &'static str = include_str!("../data/day6.txt");
+
+pub fn day6a() -> String {
+    unimplemented!();
+}
+
+pub fn day6b() -> String {
+    unimplemented!();
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    const TEST_INPUT: &'static str = "....#.....
+.........#
+..........
+..#.......
+.......#..
+..........
+.#..^.....
+........#.
+#.........
+......#...
+";
+}

2024/src/main.rs

@@ -2,6 +2,8 @@ mod day1;
 mod day2;
 mod day3;
 mod day4;
+mod day5;
+mod day6;
 
 fn main() {
     let day = std::env::args().skip(1).next();
@@ -15,6 +17,10 @@ fn main() {
         Some("3b") => day3::day3b(),
         Some("4a") => day4::day4a(),
         Some("4b") => day4::day4b(),
+        Some("5a") => day5::day5a(),
+        Some("5b") => day5::day5b(),
+        Some("6a") => day6::day6a(),
+        Some("6b") => day6::day6b(),
         _ => panic!("unrecognized day"),
     };