From 8673603676dc4e10a13da96a54c6ea10034ecf38 Mon Sep 17 00:00:00 2001
From: Lars Martens <lars@martens.red>
Date: Wed, 10 Dec 2025 22:17:18 +0100
Subject: [PATCH] Solve 10

---
 Cargo.lock    | 128 +++++++++++++++++++++++++++++++++++++++++---
 Cargo.toml    |   1 +
 src/bin/10.rs | 145 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 267 insertions(+), 7 deletions(-)
 create mode 100644 src/bin/10.rs

diff --git a/Cargo.lock b/Cargo.lock
index 387ebd7..cd31656 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -34,9 +34,16 @@ dependencies = [
  "cached",
  "glam",
  "itertools",
+ "microlp",
  "rayon",
 ]
 
+[[package]]
+name = "autocfg"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
+
 [[package]]
 name = "bumpalo"
 version = "3.19.0"
@@ -208,6 +215,74 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "log"
+version = "0.4.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34080505efa8e45a4b816c349525ebe327ceaa8559756f0356cba97ef3bf7432"
+
+[[package]]
+name = "matrixmultiply"
+version = "0.3.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a06de3016e9fae57a36fd14dba131fccf49f74b40b7fbdb472f96e361ec71a08"
+dependencies = [
+ "autocfg",
+ "rawpointer",
+]
+
+[[package]]
+name = "microlp"
+version = "0.2.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51d1790c73b93164ff65868f63164497cb32339458a9297e17e212d91df62258"
+dependencies = [
+ "log",
+ "sprs",
+]
+
+[[package]]
+name = "ndarray"
+version = "0.17.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0c7c9125e8f6f10c9da3aad044cc918cf8784fa34de857b1aa68038eb05a50a9"
+dependencies = [
+ "matrixmultiply",
+ "num-complex",
+ "num-integer",
+ "num-traits",
+ "portable-atomic",
+ "portable-atomic-util",
+ "rawpointer",
+]
+
+[[package]]
+name = "num-complex"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73f88a1307638156682bada9d7604135552957b7818057dcef22705b4d509495"
+dependencies = [
+ "num-traits",
+]
+
+[[package]]
+name = "num-integer"
+version = "0.1.46"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7969661fd2958a5cb096e56c8e1ad0444ac2bbcd0061bd28660485a44879858f"
+dependencies = [
+ "num-traits",
+]
+
+[[package]]
+name = "num-traits"
+version = "0.2.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "071dfc062690e90b734c0b2273ce72ad0ffa95f0c74596bc250dcfd960262841"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.20.2"
@@ -215,23 +290,44 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1261fe7e33c73b354eab43b1273a57c8f967d0391e80353e51f764ac02cf6775"
 
 [[package]]
-name = "proc-macro2"
-version = "1.0.92"
+name = "portable-atomic"
+version = "1.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "37d3544b3f2748c54e147655edb5025752e2303145b5aefb3c3ea2c78b973bb0"
+checksum = "f84267b20a16ea918e43c6a88433c2d54fa145c92a811b5b047ccbe153674483"
+
+[[package]]
+name = "portable-atomic-util"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d8a2f0d8d040d7848a709caf78912debcc3f33ee4b3cac47d73d1e1069e83507"
+dependencies = [
+ "portable-atomic",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.103"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ee95bc4ef87b8d5ba32e8b7714ccc834865276eab0aed5c9958d00ec45f49e8"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.37"
+version = "1.0.42"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b5b9d34b8991d19d98081b46eacdd8eb58c6f2b201139f7c5f643cc155a633af"
+checksum = "a338cc41d27e6cc6dce6cefc13a0729dfbb81c262b1f519331575dd80ef3067f"
 dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "rawpointer"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "60a357793950651c4ed0f3f52338f53b2f809f32d83a07f72909fa13e4c6c1e3"
+
 [[package]]
 name = "rayon"
 version = "1.11.0"
@@ -258,6 +354,24 @@ version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b39cdef0fa800fc44525c84ccb54a029961a8215f9619753635a9c0d2538d46d"
 
+[[package]]
+name = "smallvec"
+version = "1.15.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "67b1b7a3b5fe4f1376887184045fcf45c69e92af734b7aaddc05fb777b6fbd03"
+
+[[package]]
+name = "sprs"
+version = "0.11.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6dca58a33be2188d4edc71534f8bafa826e787cc28ca1c47f31be3423f0d6e55"
+dependencies = [
+ "ndarray",
+ "num-complex",
+ "num-traits",
+ "smallvec",
+]
+
 [[package]]
 name = "strsim"
 version = "0.11.1"
@@ -266,9 +380,9 @@ checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
 [[package]]
 name = "syn"
-version = "2.0.89"
+version = "2.0.111"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "44d46482f1c1c87acd84dea20c1bf5ebff4c757009ed6bf19cfd36fb10e92c4e"
+checksum = "390cc9a294ab71bdb1aa2e99d13be9c753cd2d7bd6560c77118597410c4d2e87"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/Cargo.toml b/Cargo.toml
index df45d61..2530fa7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,6 +8,7 @@ anyhow = "1.0.100"
 cached = "0.56.0"
 glam = "0.30.9"
 itertools = "0.14.0"
+microlp = "0.2.11"
 rayon = "1.11.0"
 
 [profile.release]
diff --git a/src/bin/10.rs b/src/bin/10.rs
new file mode 100644
index 0000000..d73376f
--- /dev/null
+++ b/src/bin/10.rs
@@ -0,0 +1,145 @@
+use aoc::*;
+use microlp::{ComparisonOp, OptimizationDirection, Problem};
+use std::collections::VecDeque;
+
+const INPUT: &str = include_str!("../../input/10");
+
+fn main() {
+    println!("Part 1: {}", part1(INPUT));
+    println!("Part 2: {}", part2(INPUT));
+}
+
+#[test]
+fn example() {
+    assert_example!(part1, "10-test", 7);
+    assert_example!(part2, "10-test", 33);
+}
+
+fn part1(input: &str) -> usize {
+    parse_input(input).iter().map(minimum_light_presses).sum()
+}
+
+fn part2(input: &str) -> usize {
+    parse_input(input).iter().map(minimum_joltage_presses).sum()
+}
+
+#[derive(Default, Debug)]
+struct Machine {
+    required_lights: Vec<bool>,
+    buttons: Vec<Button>,
+    required_joltages: Vec<usize>,
+}
+
+impl Machine {
+    fn parse(input: &str) -> Self {
+        let mut m = Machine::default();
+        for part in input.split_whitespace() {
+            if part.starts_with('[') {
+                m.required_lights = parse_lights(part);
+            } else if part.starts_with('(') {
+                m.buttons.push(parse_button(part));
+            } else if part.starts_with('{') {
+                m.required_joltages = parse_joltages(part);
+            } else {
+                panic!("Unknown part '{}'", part);
+            }
+        }
+        m
+    }
+}
+
+fn minimum_light_presses(machine: &Machine) -> usize {
+    let mut work = VecDeque::new();
+    work.push_back((vec![false; machine.required_lights.len()], 0usize));
+
+    while let Some((lights, presses)) = work.pop_front() {
+        let matches = lights.iter().eq(&machine.required_lights);
+        if matches {
+            return presses;
+        }
+
+        let new_lights = machine
+            .buttons
+            .iter()
+            .map(|b| (press_light(&lights, b), presses + 1));
+        work.extend(new_lights);
+    }
+
+    unreachable!()
+}
+
+fn minimum_joltage_presses(machine: &Machine) -> usize {
+    let mut problem = Problem::new(OptimizationDirection::Minimize);
+    let mut buttons_vars = Vec::new();
+    for _ in 0..machine.buttons.len() {
+        let var = problem.add_integer_var(1.0, (0, i32::MAX));
+        buttons_vars.push(var);
+    }
+
+    for (i, joltage) in machine.required_joltages.iter().copied().enumerate() {
+        let vars = buttons_vars
+            .iter()
+            .copied()
+            .zip(&machine.buttons)
+            .filter(|(_var, button)| button.contains(&i))
+            .map(|(var, _button)| (var, 1.0));
+        problem.add_constraint(vars, ComparisonOp::Eq, joltage as f64);
+    }
+
+    let solution = problem.solve().unwrap();
+    buttons_vars
+        .into_iter()
+        .map(|var| solution[var].round() as usize)
+        .sum()
+}
+
+fn press_light(lights: &[bool], button: &Button) -> Vec<bool> {
+    let mut lights = lights.to_vec();
+    for &b in button {
+        lights[b] ^= true;
+    }
+    lights
+}
+
+fn parse_lights(input: &str) -> Vec<bool> {
+    input
+        .strip_prefix('[')
+        .unwrap()
+        .strip_suffix(']')
+        .unwrap()
+        .chars()
+        .map(|c| match c {
+            '.' => false,
+            '#' => true,
+            other => panic!("unknown light char '{other}'"),
+        })
+        .collect()
+}
+
+type Button = Vec<usize>;
+
+fn parse_button(input: &str) -> Button {
+    input
+        .strip_prefix('(')
+        .unwrap()
+        .strip_suffix(')')
+        .unwrap()
+        .split(',')
+        .map(|c| c.parse().unwrap())
+        .collect()
+}
+
+fn parse_joltages(input: &str) -> Vec<usize> {
+    input
+        .strip_prefix('{')
+        .unwrap()
+        .strip_suffix('}')
+        .unwrap()
+        .split(',')
+        .map(|c| c.parse().unwrap())
+        .collect()
+}
+
+fn parse_input(input: &str) -> Vec<Machine> {
+    input.lines().map(Machine::parse).collect()
+}