Day 23 solutions

Author: Cadiac

README.md

@@ -108,3 +108,4 @@ This should start the server at `localhost:8080`.
 ❄️ [Day 20](aoc-solver/src/y2024/day20.rs)
 ❄️ [Day 21](aoc-solver/src/y2024/day21.rs)
 ❄️ [Day 22](aoc-solver/src/y2024/day22.rs)
+❄️ [Day 23](aoc-solver/src/y2024/day23.rs)

aoc-solver/src/y2024/day23.rs

@@ -0,0 +1,163 @@
+use std::collections::{HashMap, HashSet};
+
+use crate::solution::{AocError, Solution};
+
+fn parse(input: &str) -> Result<HashMap<&str, HashSet<&str>>, AocError> {
+    let mut network: HashMap<&str, HashSet<&str>> = HashMap::new();
+
+    for row in input.lines() {
+        let (first, second) = row
+            .split_once("-")
+            .ok_or_else(|| AocError::parse(row, "Invalid network node"))?;
+
+        network.entry(first).or_default().insert(second);
+        network.entry(second).or_default().insert(first);
+    }
+
+    Ok(network)
+}
+
+pub struct Day23;
+impl Solution for Day23 {
+    type A = u32;
+    type B = String;
+
+    fn default_input(&self) -> &'static str {
+        include_str!("../../../inputs/2024/day23.txt")
+    }
+
+    fn part_1(&self, input: &str) -> Result<u32, AocError> {
+        let network = parse(input)?;
+
+        let mut networks_of_three: HashSet<Vec<&str>> = HashSet::new();
+
+        for (first, edges) in network.iter() {
+            if first.starts_with("t") {
+                for second in edges {
+                    for third in network[second].intersection(edges) {
+                        let mut group = vec![*first, *second, *third];
+                        group.sort();
+                        networks_of_three.insert(group);
+                    }
+                }
+            }
+        }
+
+        Ok(networks_of_three.len() as u32)
+    }
+
+    fn part_2(&self, input: &str) -> Result<String, AocError> {
+        let network = parse(input)?;
+
+        let mut largest = network
+            .iter()
+            .map(|(current, edges)| {
+                let mut interconnected = vec![*current];
+
+                for edge in edges {
+                    if interconnected
+                        .iter()
+                        .all(|node| network[edge].contains(node))
+                    {
+                        interconnected.push(*edge);
+                    }
+                }
+
+                interconnected
+            })
+            .max_by(|a, b| a.len().cmp(&b.len()))
+            .ok_or_else(|| AocError::logic("No groups found"))?;
+
+        largest.sort();
+        let password = largest.join(",");
+
+        Ok(password)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_solves_part1_example() {
+        assert_eq!(
+            Day23.part_1(
+                "kh-tc\n\
+                 qp-kh\n\
+                 de-cg\n\
+                 ka-co\n\
+                 yn-aq\n\
+                 qp-ub\n\
+                 cg-tb\n\
+                 vc-aq\n\
+                 tb-ka\n\
+                 wh-tc\n\
+                 yn-cg\n\
+                 kh-ub\n\
+                 ta-co\n\
+                 de-co\n\
+                 tc-td\n\
+                 tb-wq\n\
+                 wh-td\n\
+                 ta-ka\n\
+                 td-qp\n\
+                 aq-cg\n\
+                 wq-ub\n\
+                 ub-vc\n\
+                 de-ta\n\
+                 wq-aq\n\
+                 wq-vc\n\
+                 wh-yn\n\
+                 ka-de\n\
+                 kh-ta\n\
+                 co-tc\n\
+                 wh-qp\n\
+                 tb-vc\n\
+                 td-yn"
+            ),
+            Ok(7)
+        );
+    }
+
+    #[test]
+    fn it_solves_part2_example() {
+        assert_eq!(
+            Day23.part_2(
+                "kh-tc\n\
+                 qp-kh\n\
+                 de-cg\n\
+                 ka-co\n\
+                 yn-aq\n\
+                 qp-ub\n\
+                 cg-tb\n\
+                 vc-aq\n\
+                 tb-ka\n\
+                 wh-tc\n\
+                 yn-cg\n\
+                 kh-ub\n\
+                 ta-co\n\
+                 de-co\n\
+                 tc-td\n\
+                 tb-wq\n\
+                 wh-td\n\
+                 ta-ka\n\
+                 td-qp\n\
+                 aq-cg\n\
+                 wq-ub\n\
+                 ub-vc\n\
+                 de-ta\n\
+                 wq-aq\n\
+                 wq-vc\n\
+                 wh-yn\n\
+                 ka-de\n\
+                 kh-ta\n\
+                 co-tc\n\
+                 wh-qp\n\
+                 tb-vc\n\
+                 td-yn"
+            ),
+            Ok(String::from("co,de,ka,ta"))
+        );
+    }
+}

aoc-solver/src/y2024/mod.rs

@@ -22,11 +22,11 @@ pub mod day19;
 pub mod day20;
 pub mod day21;
 pub mod day22;
-// pub mod day23;
+pub mod day23;
 // pub mod day24;
 // pub mod day25;
 
-pub const MAX_DAYS: u8 = 22;
+pub const MAX_DAYS: u8 = 23;
 
 pub struct Y2024;
 
@@ -55,7 +55,7 @@ impl Solver for Y2024 {
             20 => day20::Day20.run(input, 20, 2024),
             21 => day21::Day21.run(input, 21, 2024),
             22 => day22::Day22.run(input, 22, 2024),
-            // 23 => day23::Day23.run(input, 23, 2024),
+            23 => day23::Day23.run(input, 23, 2024),
             // 24 => day24::Day24.run(input, 24, 2024),
             // 25 => day25::Day25.run(input, 25, 2024),
             _ => vec![String::from("Solution not implemented (yet?)")],
@@ -97,7 +97,7 @@ impl Solver for Y2024 {
             20 => include_str!("./day20.rs"),
             21 => include_str!("./day21.rs"),
             22 => include_str!("./day22.rs"),
-            // 23 => include_str!("./day23.rs"),
+            23 => include_str!("./day23.rs"),
             // 24 => include_str!("./day24.rs"),
             // 25 => include_str!("./day25.rs"),
             _ => unimplemented!(),

aoc-web/src/header.rs

@@ -43,6 +43,7 @@ pub fn header(props: &HeaderProps) -> Html {
                                     <NavLink route={Route::Solution { year: 2024, day: 20 }} current={props.route.clone()} text={"20"}/>
                                     <NavLink route={Route::Solution { year: 2024, day: 21 }} current={props.route.clone()} text={"21"}/>
                                     <NavLink route={Route::Solution { year: 2024, day: 22 }} current={props.route.clone()} text={"22"}/>
+                                    <NavLink route={Route::Solution { year: 2024, day: 23 }} current={props.route.clone()} text={"23"}/>
                                 </>
                             }
                         },