day10: part1

README.md

@@ -1,6 +1,6 @@
 <!-- AOC TILES BEGIN -->
 <h1 align="center">
-  2025 - 17 ⭐ - Rust
+  2025 - 18 ⭐ - Rust
 </h1>
 <a href="src/day1.rs">
   <img src=".aoc_tiles/tiles/2025/01.png" width="161px">
@@ -29,4 +29,7 @@
 <a href="src/day9.rs">
   <img src=".aoc_tiles/tiles/2025/09.png" width="161px">
 </a>
+<a href="src/day10.rs">
+  <img src=".aoc_tiles/tiles/2025/10.png" width="161px">
+</a>
 <!-- AOC TILES END -->

src/day10.rs

@@ -0,0 +1,185 @@
+use std::{collections::BinaryHeap, iter::repeat_n};
+
+use aoc_runner_derive::{aoc, aoc_generator};
+use itertools::Itertools;
+use regex::Regex;
+
+#[derive(Clone, Debug, Default)]
+struct MachineDefinition {
+    desired: Vec<bool>,
+    buttons: Vec<Vec<usize>>,
+    joltages: Vec<u64>,
+}
+
+impl MachineDefinition {
+    fn create<'a>(&'a self) -> Machine<'a> {
+        Machine {
+            d: self,
+            lights: Vec::from_iter(repeat_n(false, self.desired.len())),
+        }
+    }
+}
+
+impl From<&str> for MachineDefinition {
+    fn from(value: &str) -> Self {
+        let parse_re = Regex::new(
+            r##"\[(?<desired>[.#]+)\] (?<buttons>(\([0-9,]+\) ?)+) \{(?<joltages>[0-9,]+)\}"##,
+        )
+        .unwrap();
+
+        let parts = parse_re.captures(value).unwrap();
+
+        MachineDefinition {
+            desired: parts["desired"].chars().map(|c| c == '#').collect(),
+            buttons: parts["buttons"]
+                .split_ascii_whitespace()
+                .map(|s| {
+                    s[1..s.len() - 1]
+                        .split(',')
+                        .map(|n| n.parse().unwrap())
+                        .collect()
+                })
+                .collect(),
+            joltages: parts["joltages"]
+                .split(',')
+                .map(|n| n.parse().unwrap())
+                .collect(),
+        }
+    }
+}
+
+#[derive(Clone, Debug)]
+struct Machine<'a> {
+    d: &'a MachineDefinition,
+    lights: Vec<bool>,
+}
+
+impl<'a> Machine<'a> {
+    /// Get the state after pressing `button`, returns None if the state is as desired
+    fn press(&self, button: usize) -> Option<Self> {
+        let mut new_state = self.lights.clone();
+        for light in &self.d.buttons[button] {
+            new_state[*light] = !new_state[*light]
+        }
+        if new_state == self.d.desired {
+            None
+        } else {
+            Some(Machine {
+                d: self.d,
+                lights: new_state,
+            })
+        }
+    }
+
+    /// Get the possible states from the current position
+    fn next_states(&self) -> Vec<(usize, Option<Machine<'a>>)> {
+        self.d
+            .buttons
+            .iter()
+            .enumerate()
+            .map(|(i, _but)| (i, self.press(i)))
+            .collect()
+    }
+}
+
+#[derive(Debug, Clone)]
+struct PressSet<'a> {
+    machine: Machine<'a>,
+    presses: Vec<usize>,
+}
+
+// NOTE: All compares are reversed so our max heap becomes a min heap
+impl<'a> Eq for PressSet<'a> {}
+
+impl<'a> PartialEq for PressSet<'a> {
+    fn eq(&self, other: &Self) -> bool {
+        other.presses.len().eq(&self.presses.len())
+    }
+}
+
+impl<'a> PartialOrd for PressSet<'a> {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        other.presses.len().partial_cmp(&self.presses.len())
+    }
+}
+
+impl<'a> Ord for PressSet<'a> {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        other.presses.len().cmp(&self.presses.len())
+    }
+}
+
+fn find_best<'a>(md: &'a MachineDefinition) -> Vec<usize> {
+    let m = md.create();
+    let mut to_check = BinaryHeap::new();
+    for next in m.next_states() {
+        if let Some(new_m) = next.1 {
+            to_check.push(PressSet {
+                presses: vec![next.0],
+                machine: new_m.clone(),
+            })
+        } else {
+            // what we found a solution on the first move?
+            return vec![next.0];
+        }
+    }
+    while let Some(candidate) = to_check.pop() {
+        let cm = candidate.machine.clone();
+        for next in cm.next_states() {
+            let mut presses = candidate.presses.clone();
+            presses.push(next.0);
+            if let Some(new_m) = next.1 {
+                to_check.push(PressSet {
+                    presses,
+                    machine: new_m.clone(),
+                })
+            } else {
+                return presses;
+            }
+        }
+    }
+    panic!()
+}
+
+#[aoc_generator(day10)]
+fn parse(input: &str) -> Vec<MachineDefinition> {
+    input.lines().map(|l| l.into()).collect()
+}
+
+#[aoc(day10, part1)]
+fn part1(input: &Vec<MachineDefinition>) -> u64 {
+    input
+        .into_iter()
+        .map(|md| find_best(md))
+        // .inspect(|sol| println!("  [{sol:?}]"))
+        .map(|sol| sol.len() as u64)
+        .sum()
+}
+
+#[aoc(day10, part2)]
+fn part2(input: &Vec<MachineDefinition>) -> u64 {
+    0
+}
+
+#[cfg(test)]
+mod tests {
+    use rstest::rstest;
+
+    use super::*;
+
+    const EXAMPLE: &str = "[.##.] (3) (1,3) (2) (2,3) (0,2) (0,1) {3,5,4,7}
+[...#.] (0,2,3,4) (2,3) (0,4) (0,1,2) (1,2,3,4) {7,5,12,7,2}
+[.###.#] (0,1,2,3,4) (0,3,4) (0,1,2,4,5) (1,2) {10,11,11,5,10,5}";
+
+    #[rstest]
+    #[case(EXAMPLE, 7)]
+    fn part1_example(#[case] input: &str, #[case] expected: u64) {
+        assert_eq!(part1(&parse(input)), expected);
+    }
+
+    #[rstest]
+    #[case(EXAMPLE, 0)]
+    fn part2_example(#[case] input: &str, #[case] expected: u64) {
+        assert_eq!(part2(&parse(input)), expected);
+    }
+}

src/lib.rs

@@ -1,4 +1,5 @@
 mod day1;
+mod day10;
 mod day2;
 mod day3;
 mod day4;