day 10 (with library)

Cargo.lock

@@ -10,6 +10,7 @@ dependencies = [
  "aoc-runner-derive",
  "faer",
  "itertools",
+ "microlp",
 ]
 
 [[package]]
@@ -614,12 +615,32 @@ dependencies = [
  "regex-automata",
 ]
 
+[[package]]
+name = "matrixmultiply"
+version = "0.3.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a06de3016e9fae57a36fd14dba131fccf49f74b40b7fbdb472f96e361ec71a08"
+dependencies = [
+ "autocfg",
+ "rawpointer",
+]
+
 [[package]]
 name = "memchr"
 version = "2.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f52b00d39961fc5b2736ea853c9cc86238e165017a493d1d5c8eac6bdc4cc273"
 
+[[package]]
+name = "microlp"
+version = "0.2.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51d1790c73b93164ff65868f63164497cb32339458a9297e17e212d91df62258"
+dependencies = [
+ "log",
+ "sprs",
+]
+
 [[package]]
 name = "nano-gemm"
 version = "0.1.3"
@@ -690,6 +711,21 @@ dependencies = [
  "nano-gemm-core",
 ]
 
+[[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 = "npyz"
 version = "0.8.4"
@@ -821,6 +857,21 @@ version = "0.2.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3b3cff922bd51709b605d9ead9aa71031d81447142d828eb4a6eba76fe619f9b"
 
+[[package]]
+name = "portable-atomic"
+version = "1.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+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 = "ppv-lite86"
 version = "0.2.21"
@@ -972,6 +1023,12 @@ dependencies = [
  "bitflags",
 ]
 
+[[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"
@@ -1135,6 +1192,18 @@ dependencies = [
  "rayon",
 ]
 
+[[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 = "syn"
 version = "1.0.109"

Cargo.toml

@@ -9,3 +9,4 @@ aoc-runner = "0.3.0"
 aoc-runner-derive = "0.3.0"
 itertools = "0.14.0"
 faer = "0.23"
+microlp = "0.2.11"

src/day10.rs

@@ -1,18 +1,19 @@
-use std::collections::{HashMap, HashSet};
+use std::collections::HashMap;
 
 use itertools::Itertools;
+use microlp::{ComparisonOp, OptimizationDirection, Problem, Variable};
 
 #[aoc(day10, part1)]
 pub fn part1(input: &str) -> u32 {
     let machines = parse(input);
-    for machine in &machines {
+    // for machine in &machines {
-        println!(
+    //     println!(
-            "num buttons: {}    num lights: {}  diff: {}",
+    //         "num buttons: {}    num lights: {}  diff: {}",
-            machine.buttons.len(),
+    //         machine.buttons.len(),
-            machine.lights.len(),
+    //         machine.lights.len(),
-            machine.buttons.len() as i32 - machine.lights.len() as i32
+    //         machine.buttons.len() as i32 - machine.lights.len() as i32
-        );
+    //     );
-    }
+    // }
     machines.into_iter().map(|m| m.button_presses()).sum()
 }
 
@@ -33,9 +34,31 @@ impl Machine {
     fn joltage_presses(self: Machine) -> u32 {
         // Method: Set up a linear set of equations A^Tx=b, where A contains
         // the coordinates of the buttons (one row per button) plus coordinates
-        // associated with optimisation parameters
+        // associated with optimisation parameters; or use a milp library :)
+        let mut problem = Problem::new(OptimizationDirection::Minimize);
+        let vars: Vec<Variable> = (0..self.buttons.len())
+            .map(|_| problem.add_integer_var(1.0, (0, *self.joltage.iter().max().unwrap() as i32)))
+            .collect();
 
-        0
+        for (i, joltage) in self.joltage.iter().enumerate() {
+            problem.add_constraint(
+                vars.iter()
+                    .zip(&self.buttons)
+                    .map(|(var, button)| (*var, button.contains(&(i as u32)) as i32 as f64))
+                    .collect::<Vec<(Variable, f64)>>(),
+                ComparisonOp::Eq,
+                *joltage as f64,
+            );
+        }
+
+        println!("{:?}", problem);
+
+        problem
+            .solve()
+            .unwrap()
+            .iter()
+            .map(|(_, value)| value.round() as u32)
+            .sum()
     }
 
     fn button_presses(self: Machine) -> u32 {

src/lib.rs

@@ -4,10 +4,10 @@ extern crate aoc_runner;
 extern crate aoc_runner_derive;
 
 pub mod day1;
-pub mod day2;
+pub mod day10;
-// pub mod day10;
 pub mod day11;
 pub mod day12;
+pub mod day2;
 pub mod day3;
 pub mod day4;
 pub mod day5;