day25: complete solution sill need to finish day 21 for the last star!

README.md

@@ -1,6 +1,6 @@
 <!-- AOC TILES BEGIN -->
 <h1 align="center">
-  2024 - 44 ⭐ - Rust
+  2024 - 48 ⭐ - Rust
 </h1>
 <a href="src/day1.rs">
   <img src=".aoc_tiles/tiles/2024/01.png" width="161px">
@@ -71,4 +71,10 @@
 <a href="src/day23.rs">
   <img src=".aoc_tiles/tiles/2024/23.png" width="161px">
 </a>
+<a href="src/day24.rs">
+  <img src=".aoc_tiles/tiles/2024/24.png" width="161px">
+</a>
+<a href="src/day25.rs">
+  <img src=".aoc_tiles/tiles/2024/25.png" width="161px">
+</a>
 <!-- AOC TILES END -->

src/day23.rs

@@ -1,8 +1,7 @@
-use std::fmt::Debug;
-
 use aoc_runner_derive::aoc;
 use itertools::Itertools;
 use rustc_hash::{FxHashMap, FxHashSet};
+use std::fmt::{Debug, Display};
 
 #[derive(Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
 struct Node([char; 2]);
@@ -13,9 +12,15 @@ impl Debug for Node {
     }
 }
 
+impl Display for Node {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_fmt(format_args!("{}", self.0.iter().join("")))
+    }
+}
+
 impl From<[char; 2]> for Node {
     fn from(value: [char; 2]) -> Self {
-        Node(value)
+        Self(value)
     }
 }
 
@@ -28,8 +33,8 @@ impl TryFrom<Vec<char>> for Node {
 }
 
 struct Network {
-    nodes: Vec<Node>,
+    nodes: FxHashSet<Node>,
-    edges: FxHashMap<Node, Vec<Node>>,
+    edges: FxHashMap<Node, FxHashSet<Node>>,
 }
 
 impl Network {
@@ -51,11 +56,52 @@ impl Network {
         }
         sets
     }
+    // Had to study Wikipedia for this one
+    // https://en.wikipedia.org/wiki/Bron%E2%80%93Kerbosch_algorithm
+    fn bron_kerbosch(
+        &self,
+        r: FxHashSet<Node>,
+        mut p: FxHashSet<Node>,
+        mut x: FxHashSet<Node>,
+    ) -> Vec<FxHashSet<Node>> {
+        let mut results = Vec::new();
+        if p.is_empty() && x.is_empty() {
+            return vec![r];
+        } else if p.is_empty() {
+            return Vec::new();
+        }
+        // choose the pivot with the most neighbours, to minimize the size of p_iter
+        let p_iter = if let Some(pivot) = p.union(&x).max_by(|a, b| self.edges[a].len().cmp(&self.edges[b].len())) {
+            FxHashSet::from_iter(p.difference(self.edges.get(pivot).unwrap()).copied())
+        } else {
+            p.clone()
+        };
+        for node in &p_iter {
+            let mut new_r = r.clone();
+            new_r.insert(*node);
+
+            let neighbours = FxHashSet::from_iter(self.edges.get(node).unwrap().iter().copied());
+            let new_p = FxHashSet::from_iter(p.intersection(&neighbours).copied());
+            let new_x = FxHashSet::from_iter(x.intersection(&neighbours).copied());
+
+            results.extend(self.bron_kerbosch(new_r, new_p, new_x).into_iter());
+            p.remove(node);
+            x.insert(*node);
+        }
+        results
+    }
+    fn maximal_subgraphs(&self) -> Vec<FxHashSet<Node>> {
+        self.bron_kerbosch(
+            FxHashSet::default(),
+            FxHashSet::from_iter(self.nodes.iter().copied()),
+            FxHashSet::default(),
+        )
+    }
 }
 
 impl From<&str> for Network {
     fn from(input: &str) -> Self {
-        let mut nodes = Vec::new();
+        let mut nodes = FxHashSet::default();
         let mut edges = FxHashMap::default();
         for line in input.lines() {
             let (node1, node2) = line.split_once('-').unwrap();
@@ -64,13 +110,13 @@ impl From<&str> for Network {
                 node2.chars().collect_vec().try_into().unwrap(),
             );
             if !nodes.contains(&node1) {
-                nodes.push(node1);
+                nodes.insert(node1);
             }
             if !nodes.contains(&node2) {
-                nodes.push(node2);
+                nodes.insert(node2);
             }
-            edges.entry(node1).or_insert(Vec::new()).push(node2);
+            edges.entry(node1).or_insert(FxHashSet::default()).insert(node2);
-            edges.entry(node2).or_insert(Vec::new()).push(node1);
+            edges.entry(node2).or_insert(FxHashSet::default()).insert(node1);
         }
         Self { nodes, edges }
     }
@@ -83,17 +129,21 @@ fn parse(input: &str) -> Network {
 #[aoc(day23, part1)]
 pub fn part1(input: &str) -> i64 {
     let network = parse(input);
-    println!("edges: {:?}", network.edges);
+
     let sets = network.groups_3();
     let t_count = sets.iter().filter(|set| set.iter().any(|s| s.0[0] == 't')).count();
-    println!("groups: {:?}", sets);
+
-    
     t_count as i64
 }
 
 #[aoc(day23, part2)]
 pub fn part2(input: &str) -> String {
-    todo!()
+    let network = parse(input);
+    let best_sets = network.maximal_subgraphs();
+    let largest_set = best_sets.iter().max_by(|a, b| a.len().cmp(&b.len())).unwrap();
+    let mut largest = largest_set.iter().collect_vec();
+    largest.sort();
+    largest.iter().join(",")
 }
 
 #[cfg(test)]

src/day24.rs

@@ -0,0 +1,229 @@
+use aoc_runner_derive::aoc;
+use itertools::Itertools;
+use nom::And;
+use regex::Regex;
+use rustc_hash::FxHashMap;
+
+#[derive(Copy, Clone, Debug)]
+enum Op {
+    And,
+    Or,
+    Xor,
+    Constant,
+}
+
+impl From<&str> for Op {
+    fn from(value: &str) -> Self {
+        match value {
+            "AND" => Self::And,
+            "OR" => Self::Or,
+            "XOR" => Self::Xor,
+            s => panic!("invalid operation {}", s),
+        }
+    }
+}
+
+#[derive(Clone, Debug)]
+struct Gate {
+    op: Op,
+    value: Option<bool>,
+    arguments: [String; 2],
+}
+
+impl Gate {
+    fn eval(&self, machine: &GateMachine) -> bool {
+        match self.op {
+            Op::And => machine.val_of(&self.arguments[0]) && machine.val_of(&self.arguments[1]),
+            Op::Or => machine.val_of(&self.arguments[0]) || machine.val_of(&self.arguments[1]),
+            Op::Xor => machine.val_of(&self.arguments[0]) ^ machine.val_of(&self.arguments[1]),
+            Op::Constant => self.value.unwrap(),
+        }
+    }
+}
+
+#[derive(Debug)]
+struct GateMachine {
+    gates: FxHashMap<String, Gate>,
+}
+
+impl GateMachine {
+    fn val_of(&self, gate: &str) -> bool {
+        println!("gate: {}", gate);
+        if let Some(val) = self.gates[gate].value {
+            val
+        } else {
+            self.gates[gate].eval(self)
+        }
+    }
+}
+
+fn parse(input: &str) -> GateMachine {
+    let mut gates = FxHashMap::default();
+    for line in input.lines() {
+        println!("{line}");
+        let const_re = Regex::new(r"^([xyz][0-9]{2}): ([01])$").unwrap();
+        let gate_re = Regex::new(r"^([a-z0-9]{3}) (AND|XOR|OR) ([a-z0-9]{3}) -> ([a-z0-9]{3})$").unwrap();
+
+        if let Some(caps) = const_re.captures(line) {
+            println!(" is const: {:?}", caps);
+            gates.insert(
+                caps[1].to_string(),
+                Gate {
+                    op: Op::Constant,
+                    value: if &caps[2] == "1" { Some(true) } else { Some(false) },
+                    arguments: [String::new(), String::new()],
+                },
+            );
+        } else if let Some(caps) = gate_re.captures(line) {
+            println!(" is gate: {:?}", caps);
+            gates.insert(
+                caps[4].to_string(),
+                Gate {
+                    op: Op::from(&caps[2]),
+                    value: None,
+                    arguments: [caps[1].to_string(), caps[3].to_string()],
+                },
+            );
+        }
+    }
+    GateMachine { gates }
+}
+
+#[aoc(day24, part1)]
+pub fn part1(input: &str) -> i64 {
+    let machine = parse(input);
+    let z_gates = machine
+        .gates
+        .keys()
+        .filter(|k| k.starts_with('z'))
+        .map(|s| (s, s.split_at(1).1.parse::<usize>().unwrap()));
+    let bit_vals = z_gates
+        .map(|(name, bit)| if machine.val_of(name) { 1 << bit } else { 0 })
+        .fold(0, |accum, val| accum | val);
+    bit_vals
+}
+
+#[aoc(day24, part2)]
+pub fn part2(input: &str) -> i64 {
+    0
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    const EXAMPLE1: &str = "x00: 1
+x01: 1
+x02: 1
+y00: 0
+y01: 1
+y02: 0
+
+x00 AND y00 -> z00
+x01 XOR y01 -> z01x00: 1
+x01: 0
+x02: 1
+x03: 1
+x04: 0
+y00: 1
+y01: 1
+y02: 1
+y03: 1
+y04: 1
+
+ntg XOR fgs -> mjb
+y02 OR x01 -> tnw
+kwq OR kpj -> z05
+x00 OR x03 -> fst
+tgd XOR rvg -> z01
+vdt OR tnw -> bfw
+bfw AND frj -> z10
+ffh OR nrd -> bqk
+y00 AND y03 -> djm
+y03 OR y00 -> psh
+bqk OR frj -> z08
+tnw OR fst -> frj
+gnj AND tgd -> z11
+bfw XOR mjb -> z00
+x03 OR x00 -> vdt
+gnj AND wpb -> z02
+x04 AND y00 -> kjc
+djm OR pbm -> qhw
+nrd AND vdt -> hwm
+kjc AND fst -> rvg
+y04 OR y02 -> fgs
+y01 AND x02 -> pbm
+ntg OR kjc -> kwq
+psh XOR fgs -> tgd
+qhw XOR tgd -> z09
+pbm OR djm -> kpj
+x03 XOR y03 -> ffh
+x00 XOR y04 -> ntg
+bfw OR bqk -> z06
+nrd XOR fgs -> wpb
+frj XOR qhw -> z04
+bqk OR frj -> z07
+y03 OR x01 -> nrd
+hwm AND bqk -> z03
+tgd XOR rvg -> z12
+tnw OR pbm -> gnj
+x02 OR y02 -> z02";
+
+    const EXAMPLE2: &str = "x00: 1
+x01: 0
+x02: 1
+x03: 1
+x04: 0
+y00: 1
+y01: 1
+y02: 1
+y03: 1
+y04: 1
+
+ntg XOR fgs -> mjb
+y02 OR x01 -> tnw
+kwq OR kpj -> z05
+x00 OR x03 -> fst
+tgd XOR rvg -> z01
+vdt OR tnw -> bfw
+bfw AND frj -> z10
+ffh OR nrd -> bqk
+y00 AND y03 -> djm
+y03 OR y00 -> psh
+bqk OR frj -> z08
+tnw OR fst -> frj
+gnj AND tgd -> z11
+bfw XOR mjb -> z00
+x03 OR x00 -> vdt
+gnj AND wpb -> z02
+x04 AND y00 -> kjc
+djm OR pbm -> qhw
+nrd AND vdt -> hwm
+kjc AND fst -> rvg
+y04 OR y02 -> fgs
+y01 AND x02 -> pbm
+ntg OR kjc -> kwq
+psh XOR fgs -> tgd
+qhw XOR tgd -> z09
+pbm OR djm -> kpj
+x03 XOR y03 -> ffh
+x00 XOR y04 -> ntg
+bfw OR bqk -> z06
+nrd XOR fgs -> wpb
+frj XOR qhw -> z04
+bqk OR frj -> z07
+y03 OR x01 -> nrd
+hwm AND bqk -> z03
+tgd XOR rvg -> z12
+tnw OR pbm -> gnj";
+
+    #[test]
+    fn part1_example() {
+        assert_eq!(part1(EXAMPLE1), 4);
+        assert_eq!(part1(EXAMPLE2), 2024);
+    }
+
+    #[test]
+    fn part2_example() {
+        assert_eq!(part2(EXAMPLE1), 0);
+    }
+}

src/day25.rs

@@ -0,0 +1,143 @@
+use aoc_runner_derive::aoc;
+use itertools::Itertools;
+
+enum LockKey {
+    Lock,
+    Key,
+}
+
+#[derive(Clone, Debug)]
+struct LockPile {
+    keys: Vec<Vec<usize>>,
+    locks: Vec<Vec<usize>>,
+}
+
+fn parse_grid(lines: &Vec<&str>) -> (LockKey, Vec<usize>) {
+    assert_eq!(lines.len(), 7);
+    if lines[0].chars().all(|c| c == '#') {
+        // lock
+        let mut pins = vec![0; 5];
+        for row in 1..lines.len() {
+            let row_s = lines[row];
+            for i in 0..row_s.len() {
+                if row_s.chars().nth(i) == Some('#') {
+                    pins[i] = row
+                }
+            }
+        }
+        (LockKey::Lock, pins)
+    } else if lines[6].chars().all(|c| c == '#') {
+        // key
+        let mut pins = vec![5; 5];
+        for row in (1..lines.len()).rev() {
+            let row_s = lines[row];
+            for i in 0..row_s.len() {
+                if row_s.chars().nth(i) == Some('#') {
+                    pins[i] = 6 - row
+                }
+            }
+        }
+        (LockKey::Key, pins)
+    } else {
+        panic!("not a lock or a key: {:?}", lines);
+    }
+}
+
+fn parse(input: &str) -> LockPile {
+    let mut locks = Vec::new();
+    let mut keys = Vec::new();
+    let mut accum: Vec<&str> = Vec::new();
+    for line in input.lines() {
+        if line == "" {
+            let (lk, pins) = parse_grid(&accum);
+            match lk {
+                LockKey::Lock => locks.push(pins),
+                LockKey::Key => keys.push(pins),
+            }
+            accum.clear();
+        } else {
+            accum.push(line);
+        }
+    }
+    if accum.len() != 0 {
+        let (lk, pins) = parse_grid(&accum);
+        match lk {
+            LockKey::Lock => locks.push(pins),
+            LockKey::Key => keys.push(pins),
+        }
+    }
+    LockPile { keys, locks }
+}
+
+fn test_lock_key(lock: &Vec<usize>, key: &Vec<usize>) -> bool {
+    !lock.iter().zip(key.iter()).any(|(lp, kp)| lp + kp > 5)
+}
+
+#[aoc(day25, part1)]
+pub fn part1(input: &str) -> i64 {
+    let lockpile = parse(input);
+
+    lockpile
+        .locks
+        .iter()
+        .cartesian_product(lockpile.keys.iter())
+        .filter(|(l, k)| test_lock_key(l, k))
+        .count() as i64
+}
+
+#[aoc(day25, part2)]
+pub fn part2(_input: &str) -> String {
+    "run the other solutions for day 25 part 2!".to_string()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    const EXAMPLE: &str = "#####
+.####
+.####
+.####
+.#.#.
+.#...
+.....
+
+#####
+##.##
+.#.##
+...##
+...#.
+...#.
+.....
+
+.....
+#....
+#....
+#...#
+#.#.#
+#.###
+#####
+
+.....
+.....
+#.#..
+###..
+###.#
+###.#
+#####
+
+.....
+.....
+.....
+#....
+#.#..
+#.#.#
+#####";
+
+    #[test]
+    fn part1_example() {
+        assert_eq!(part1(EXAMPLE), 3);
+    }
+
+    #[test]
+    fn part2_example() {}
+}

src/lib.rs

@@ -14,6 +14,8 @@ pub mod day20;
 pub mod day21;
 pub mod day22;
 pub mod day23;
+pub mod day24;
+pub mod day25;
 pub mod day3;
 pub mod day4;
 pub mod day5;