pre-commit update

.gitignore

@@ -3,3 +3,5 @@ input
 flamegraph.svg
 perf.data*
 guesses
+.aoc_tiles/*
+!.aoc_tiles/tiles/

.pre-commit-config.yaml

@@ -0,0 +1,17 @@
+repos:
+    - repo: https://github.com/LiquidFun/aoc_tiles
+      rev: 0.6.2
+      hooks:
+          - id: aoc-tiles
+            # Optionally use these arguments. Auto add tiles to git adds the tiles to git,
+            # possibly amends your commit by creating the tile images and updating the README.
+            # Language sorting shows the preference of the order of the languages to use.
+            # Exclude paterns are globs which can be used to exclude files when creating
+            # the tiles. See the customization section in the README for more flags.
+            # Simply remove the comments (#) below for args and the flags you want.
+            args:
+            - --auto-add-tiles-to-git=amend
+            - --create-all-days
+            - --overwrite-year=2024
+            #     - --language-sorting=jl,kt,py,rs
+            #     - --exclude-patterns=2021/*/*.apl,2021/*/*.py,2021/*/*.cpp

Cargo.lock

@@ -2,6 +2,18 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "ahash"
+version = "0.8.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e89da841a80418a9b391ebaea17f5c112ffaaa96f621d2c285b5174da76b9011"
+dependencies = [
+ "cfg-if",
+ "once_cell",
+ "version_check",
+ "zerocopy",
+]
+
 [[package]]
 name = "aho-corasick"
 version = "1.1.3"
@@ -11,6 +23,12 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "allocator-api2"
+version = "0.2.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "683d7910e743518b0e34f1186f92494becacb047c7b6bf616c96772180fef923"
+
 [[package]]
 name = "aoc-runner"
 version = "0.3.0"
@@ -46,7 +64,9 @@ version = "0.1.0"
 dependencies = [
  "aoc-runner",
  "aoc-runner-derive",
+ "atoi",
  "bitflags",
+ "cached",
  "grid",
  "itertools",
  "rayon",
@@ -55,12 +75,66 @@ dependencies = [
  "thread_local",
 ]
 
+[[package]]
+name = "atoi"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f28d99ec8bfea296261ca1af174f24225171fea9664ba9003cbebee704810528"
+dependencies = [
+ "num-traits",
+]
+
+[[package]]
+name = "autocfg"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ace50bade8e6234aa140d9a2f552bbee1db4d353f69b8217bc503490fc1a9f26"
+
 [[package]]
 name = "bitflags"
 version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b048fb63fd8b5923fc5aa7b340d8e156aec7ec02f0c78fa8a6ddc2613f6f71de"
 
+[[package]]
+name = "bumpalo"
+version = "3.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "79296716171880943b8470b5f8d03aa55eb2e645a4874bdbb28adb49162e012c"
+
+[[package]]
+name = "cached"
+version = "0.54.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9718806c4a2fe9e8a56fd736f97b340dd10ed1be8ed733ed50449f351dc33cae"
+dependencies = [
+ "ahash",
+ "cached_proc_macro",
+ "cached_proc_macro_types",
+ "hashbrown",
+ "once_cell",
+ "thiserror",
+ "web-time",
+]
+
+[[package]]
+name = "cached_proc_macro"
+version = "0.23.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2f42a145ed2d10dce2191e1dcf30cfccfea9026660e143662ba5eec4017d5daa"
+dependencies = [
+ "darling",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.90",
+]
+
+[[package]]
+name = "cached_proc_macro_types"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ade8366b8bd5ba243f0a58f036cc0ca8a2f069cff1a2351ef1cac6b083e16fc0"
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -92,16 +166,73 @@ version = "0.8.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "22ec99545bb0ed0ea7bb9b8e1e9122ea386ff8a48c0922e43f36d45ab09e0e80"
 
+[[package]]
+name = "darling"
+version = "0.20.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f63b86c8a8826a49b8c21f08a2d07338eec8d900540f8630dc76284be802989"
+dependencies = [
+ "darling_core",
+ "darling_macro",
+]
+
+[[package]]
+name = "darling_core"
+version = "0.20.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "95133861a8032aaea082871032f5815eb9e98cef03fa916ab4500513994df9e5"
+dependencies = [
+ "fnv",
+ "ident_case",
+ "proc-macro2",
+ "quote",
+ "strsim",
+ "syn 2.0.90",
+]
+
+[[package]]
+name = "darling_macro"
+version = "0.20.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d336a2a514f6ccccaa3e09b02d41d35330c07ddf03a62165fcec10bb561c7806"
+dependencies = [
+ "darling_core",
+ "quote",
+ "syn 2.0.90",
+]
+
 [[package]]
 name = "either"
 version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "60b1af1c220855b6ceac025d3f6ecdd2b7c4894bfe9cd9bda4fbb4bc7c0d4cf0"
 
+[[package]]
+name = "fnv"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
+
 [[package]]
 name = "grid"
 version = "0.1.0"
 
+[[package]]
+name = "hashbrown"
+version = "0.14.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5274423e17b7c9fc20b6e7e208532f9b19825d82dfd615708b70edd83df41f1"
+dependencies = [
+ "ahash",
+ "allocator-api2",
+]
+
+[[package]]
+name = "ident_case"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
+
 [[package]]
 name = "itertools"
 version = "0.13.0"
@@ -117,12 +248,37 @@ version = "1.0.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d75a2a4b1b190afb6f5425f10f6a8f959d2ea0b9c2b1d79553551850539e4674"
 
+[[package]]
+name = "js-sys"
+version = "0.3.76"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6717b6b5b077764fb5966237269cb3c64edddde4b14ce42647430a78ced9e7b7"
+dependencies = [
+ "once_cell",
+ "wasm-bindgen",
+]
+
+[[package]]
+name = "log"
+version = "0.4.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"
+
 [[package]]
 name = "memchr"
 version = "2.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
 
+[[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"
@@ -240,6 +396,12 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "strsim"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
+
 [[package]]
 name = "syn"
 version = "1.0.109"
@@ -262,6 +424,26 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "thiserror"
+version = "1.0.69"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6aaf5339b578ea85b50e080feb250a3e8ae8cfcdff9a461c9ec2904bc923f52"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.69"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4fee6c4efc90059e10f81e6d42c60a18f76588c3d74cb83a0b242a2b6c7504c1"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.90",
+]
+
 [[package]]
 name = "thread_local"
 version = "1.1.8"
@@ -277,3 +459,93 @@ name = "unicode-ident"
 version = "1.0.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "adb9e6ca4f869e1180728b7950e35922a7fc6397f7b641499e8f3ef06e50dc83"
+
+[[package]]
+name = "version_check"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
+
+[[package]]
+name = "wasm-bindgen"
+version = "0.2.99"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a474f6281d1d70c17ae7aa6a613c87fce69a127e2624002df63dcb39d6cf6396"
+dependencies = [
+ "cfg-if",
+ "once_cell",
+ "wasm-bindgen-macro",
+]
+
+[[package]]
+name = "wasm-bindgen-backend"
+version = "0.2.99"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f89bb38646b4f81674e8f5c3fb81b562be1fd936d84320f3264486418519c79"
+dependencies = [
+ "bumpalo",
+ "log",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.90",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-macro"
+version = "0.2.99"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2cc6181fd9a7492eef6fef1f33961e3695e4579b9872a6f7c83aee556666d4fe"
+dependencies = [
+ "quote",
+ "wasm-bindgen-macro-support",
+]
+
+[[package]]
+name = "wasm-bindgen-macro-support"
+version = "0.2.99"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "30d7a95b763d3c45903ed6c81f156801839e5ee968bb07e534c44df0fcd330c2"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.90",
+ "wasm-bindgen-backend",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-shared"
+version = "0.2.99"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "943aab3fdaaa029a6e0271b35ea10b72b943135afe9bffca82384098ad0e06a6"
+
+[[package]]
+name = "web-time"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a6580f308b1fad9207618087a65c04e7a10bc77e02c8e84e9b00dd4b12fa0bb"
+dependencies = [
+ "js-sys",
+ "wasm-bindgen",
+]
+
+[[package]]
+name = "zerocopy"
+version = "0.7.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b9b4fd18abc82b8136838da5d50bae7bdea537c574d8dc1a34ed098d6c166f0"
+dependencies = [
+ "zerocopy-derive",
+]
+
+[[package]]
+name = "zerocopy-derive"
+version = "0.7.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fa4f8080344d4671fb4e831a13ad1e68092748387dfc4f55e356242fae12ce3e"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.90",
+]

Cargo.toml

@@ -6,7 +6,9 @@ edition = "2021"
 [dependencies]
 aoc-runner = "0.3.0"
 aoc-runner-derive = "0.3.0"
+atoi = "2.0.0"
 bitflags = "2.6.0"
+cached = "0.54.0"
 grid = { version = "0.1.0", path = "utils/grid" }
 itertools = "0.13.0"
 rayon = "1.10.0"

README.md

@@ -0,0 +1,80 @@
+<!-- AOC TILES BEGIN -->
+<h1 align="center">
+  2024 - 26 ⭐ - Rust
+</h1>
+<a href="src/day1.rs">
+  <img src=".aoc_tiles/tiles/2024/01.png" width="161px">
+</a>
+<a href="src/day2.rs">
+  <img src=".aoc_tiles/tiles/2024/02.png" width="161px">
+</a>
+<a href="src/day3.rs">
+  <img src=".aoc_tiles/tiles/2024/03.png" width="161px">
+</a>
+<a href="src/day4.rs">
+  <img src=".aoc_tiles/tiles/2024/04.png" width="161px">
+</a>
+<a href="src/day5.rs">
+  <img src=".aoc_tiles/tiles/2024/05.png" width="161px">
+</a>
+<a href="src/day6.rs">
+  <img src=".aoc_tiles/tiles/2024/06.png" width="161px">
+</a>
+<a href="src/day7.rs">
+  <img src=".aoc_tiles/tiles/2024/07.png" width="161px">
+</a>
+<a href="src/day8.rs">
+  <img src=".aoc_tiles/tiles/2024/08.png" width="161px">
+</a>
+<a href="src/day9.rs">
+  <img src=".aoc_tiles/tiles/2024/09.png" width="161px">
+</a>
+<a href="src/day10.rs">
+  <img src=".aoc_tiles/tiles/2024/10.png" width="161px">
+</a>
+<a href="src/day11.rs">
+  <img src=".aoc_tiles/tiles/2024/11.png" width="161px">
+</a>
+<a href="src/day12.rs">
+  <img src=".aoc_tiles/tiles/2024/12.png" width="161px">
+</a>
+<a href="src/day13.rs">
+  <img src=".aoc_tiles/tiles/2024/13.png" width="161px">
+</a>
+<a href="None">
+  <img src=".aoc_tiles/tiles/2024/14.png" width="161px">
+</a>
+<a href="None">
+  <img src=".aoc_tiles/tiles/2024/15.png" width="161px">
+</a>
+<a href="None">
+  <img src=".aoc_tiles/tiles/2024/16.png" width="161px">
+</a>
+<a href="None">
+  <img src=".aoc_tiles/tiles/2024/17.png" width="161px">
+</a>
+<a href="None">
+  <img src=".aoc_tiles/tiles/2024/18.png" width="161px">
+</a>
+<a href="None">
+  <img src=".aoc_tiles/tiles/2024/19.png" width="161px">
+</a>
+<a href="None">
+  <img src=".aoc_tiles/tiles/2024/20.png" width="161px">
+</a>
+<a href="None">
+  <img src=".aoc_tiles/tiles/2024/21.png" width="161px">
+</a>
+<a href="None">
+  <img src=".aoc_tiles/tiles/2024/22.png" width="161px">
+</a>
+<a href="None">
+  <img src=".aoc_tiles/tiles/2024/23.png" width="161px">
+</a>
+<a href="None">
+  <img src=".aoc_tiles/tiles/2024/24.png" width="161px">
+</a>
+<a href="None">
+  <img src=".aoc_tiles/tiles/2024/25.png" width="161px">
+</a>
+<!-- AOC TILES END -->

src/day13.rs

@@ -0,0 +1,141 @@
+use std::io::{BufRead, Lines};
+
+use aoc_runner_derive::{aoc, aoc_generator};
+use itertools::Itertools;
+use regex::Regex;
+
+#[derive(Debug, Clone)]
+pub struct MachineAction(i64, i64);
+
+#[derive(Debug, Clone)]
+struct ClawMachine {
+    button_a: MachineAction,
+    button_b: MachineAction,
+    prize: (i64, i64),
+}
+
+impl ClawMachine {
+    fn consume_from_input<T: BufRead>(input: &mut Lines<T>) -> Option<Self> {
+        // consume any empty lines at the front
+        let ofs_re = Regex::new(r"X([+-]\d+), Y([+-]\d+)").unwrap();
+        let prize_re = Regex::new(r"X=(\d+), Y=(\d+)").unwrap();
+        // consume 3 lines - a, b, prize
+        if let Some((a_line, b_line, prize_line)) = input
+            .filter(|l| l.as_ref().is_ok_and(|l| !l.is_empty()))
+            .take(3)
+            .map(|l| l.unwrap())
+            .collect_tuple()
+        {
+            let a_caps = ofs_re.captures(&a_line).unwrap();
+            let b_caps = ofs_re.captures(&b_line).unwrap();
+            let prize_caps = prize_re.captures(&prize_line).unwrap();
+            let button_a = MachineAction(
+                a_caps.get(1).unwrap().as_str().parse().unwrap(),
+                a_caps.get(2).unwrap().as_str().parse().unwrap(),
+            );
+            let button_b = MachineAction(
+                b_caps.get(1).unwrap().as_str().parse().unwrap(),
+                b_caps.get(2).unwrap().as_str().parse().unwrap(),
+            );
+            let prize = (
+                prize_caps.get(1).unwrap().as_str().parse().unwrap(),
+                prize_caps.get(2).unwrap().as_str().parse().unwrap(),
+            );
+            Some(Self {
+                button_a,
+                button_b,
+                prize,
+            })
+        } else {
+            None
+        }
+    }
+    fn cost(moves: (i64, i64)) -> i64 {
+        moves.0 * 3 + moves.1
+    }
+    fn cheapest_prize(&self) -> Option<i64> {
+        let remainder_a = (self.button_b.0 * self.prize.1 - self.button_b.1 * self.prize.0)
+            % (self.button_b.0 * self.button_a.1 - self.button_a.0 * self.button_b.1);
+        let a = (self.button_b.0 * self.prize.1 - self.button_b.1 * self.prize.0)
+            / (self.button_b.0 * self.button_a.1 - self.button_a.0 * self.button_b.1);
+        let remainder_b = (self.prize.0 - (self.button_a.0 * a)) % self.button_b.0;
+        let b = (self.prize.0 - (self.button_a.0 * a)) / self.button_b.0;
+        if remainder_a == 0 && remainder_b == 0 {
+            Some(Self::cost((a, b)))
+        } else {
+            None
+        }
+    }
+    fn offset(&mut self, offset: i64) {
+        self.prize = (self.prize.0 + offset, self.prize.1 + offset)
+    }
+}
+
+#[derive(Debug, Clone)]
+struct ClawMachines {
+    machines: Vec<ClawMachine>,
+}
+
+impl From<&[u8]> for ClawMachines {
+    fn from(input: &[u8]) -> Self {
+        let mut machines = Vec::new();
+        let mut lines = input.lines();
+        while let Some(machine) = ClawMachine::consume_from_input(&mut lines) {
+            machines.push(machine);
+        }
+        Self { machines }
+    }
+}
+
+#[aoc_generator(day13)]
+fn parse(input: &[u8]) -> ClawMachines {
+    ClawMachines::from(input)
+}
+
+#[aoc(day13, part1)]
+fn part1(machines: &ClawMachines) -> i64 {
+    machines.machines.iter().filter_map(|m| m.cheapest_prize()).sum()
+}
+
+#[aoc(day13, part2)]
+fn part2(machines: &ClawMachines) -> i64 {
+    let mut machines = machines.clone();
+    machines
+        .machines
+        .iter_mut()
+        .filter_map(|m| {
+            m.offset(10000000000000);
+            m.cheapest_prize()
+        })
+        .sum()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    const EXAMPLE: &[u8] = b"Button A: X+94, Y+34
+Button B: X+22, Y+67
+Prize: X=8400, Y=5400
+
+Button A: X+26, Y+66
+Button B: X+67, Y+21
+Prize: X=12748, Y=12176
+
+Button A: X+17, Y+86
+Button B: X+84, Y+37
+Prize: X=7870, Y=6450
+
+Button A: X+69, Y+23
+Button B: X+27, Y+71
+Prize: X=18641, Y=10279";
+
+    #[test]
+    fn part1_example() {
+        assert_eq!(part1(&parse(EXAMPLE)), 480);
+    }
+
+    #[test]
+    fn part2_example() {
+        assert_eq!(part2(&parse(EXAMPLE)), 875318608908);
+    }
+}

src/day3.rs

@@ -1,4 +1,5 @@
 use aoc_runner_derive::{aoc, aoc_generator};
+use atoi::FromRadix10;
 use regex::bytes::Regex;
 use std::io::BufRead;
 
@@ -9,36 +10,33 @@ pub fn get_input(input: &[u8]) -> Vec<String> {
 
 // PROBLEM 1 solution
 #[aoc(day3, part1)]
-pub fn part1(input: &Vec<String>) -> u64 {
-    let mut sum = 0u64;
+pub fn part1(input: &[String]) -> u64 {
     let re = Regex::new(r"(?-u)mul\((\d+),(\d+)\)").unwrap();
-    for line in input {
-        let line = line.as_bytes();
-        for m in re.captures_iter(line) {
-            sum += std::str::from_utf8(&m[1]).unwrap().parse::<u64>().unwrap()
-                * std::str::from_utf8(&m[2]).unwrap().parse::<u64>().unwrap();
-        }
-    }
-    sum
+    input
+        .iter()
+        .map(|line| {
+            re.captures_iter(line.as_bytes())
+                .map(|m| u64::from_radix_10(&m[1]).0 * u64::from_radix_10(&m[2]).0)
+                .sum::<u64>()
+        })
+        .sum()
 }
 
 // PROBLEM 2 solution
 #[aoc(day3, part2)]
-pub fn part2(input: &Vec<String>) -> u64 {
+pub fn part2(input: &[String]) -> u64 {
     let mut sum = 0u64;
-    let mut do_mul = true;
+    let mut do_mul: u64 = 1;
     let re = Regex::new(r"(?-u)(do\(\)|don't\(\)|mul\((\d+),(\d+)\))").unwrap();
     for line in input {
         let line = line.as_bytes();
         for m in re.captures_iter(line) {
-            match std::str::from_utf8(&m[1]).unwrap() {
-                "do()" => do_mul = true,
-                "don't()" => do_mul = false,
-                _ if do_mul => {
-                    sum += std::str::from_utf8(&m[2]).unwrap().parse::<u64>().unwrap()
-                        * std::str::from_utf8(&m[3]).unwrap().parse::<u64>().unwrap()
+            match &m[1] {
+                b"do()" => do_mul = 1,
+                b"don't()" => do_mul = 0,
+                _ => {
+                    sum += u64::from_radix_10(&m[2]).0 * u64::from_radix_10(&m[3]).0 * do_mul;
                 }
-                _ => {}
             }
         }
     }

src/day5.rs

@@ -65,10 +65,7 @@ impl OrderingRules {
         }
     }
     fn is_sorted(&self, a: u64, b: u64) -> bool {
-        match self.pairs.get(&(a, b)) {
-            Some(Ordering::Less) | Some(Ordering::Equal) => true,
-            _ => false,
-        }
+        matches!(self.pairs.get(&(a, b)), Some(Ordering::Less) | Some(Ordering::Equal))
     }
 }
 

src/day7.rs

@@ -1,5 +1,4 @@
 use aoc_runner_derive::{aoc, aoc_generator};
-use itertools::Itertools;
 use rayon::iter::{IntoParallelRefIterator, ParallelIterator};
 use std::io::{BufRead, Lines};
 
@@ -27,7 +26,6 @@ impl From<&str> for Calibration {
 #[derive(Debug)]
 pub struct Calibrations {
     cals: Vec<Calibration>,
-    longest_cal: usize,
 }
 
 #[derive(Debug, Copy, Clone)]
@@ -49,64 +47,51 @@ impl Operator {
 
 impl<T: BufRead> From<Lines<T>> for Calibrations {
     fn from(input: Lines<T>) -> Self {
-        let mut cals = Vec::new();
-        let mut longest_cal = 0;
-        for line in input.map(|l| l.unwrap()) {
-            let cal: Calibration = line.as_str().into();
-            longest_cal = std::cmp::max(longest_cal, cal.numbers.len());
-            cals.push(cal);
-        }
-        Self { cals, longest_cal }
+        let cals = input.map(|l| l.unwrap().as_str().into()).collect();
+        Self { cals }
     }
 }
 
 impl Calibrations {
-    fn make_operator_sets(operators: &[Operator], n_opers: usize) -> Vec<Vec<Vec<Operator>>> {
-        (0..n_opers)
-            .map(|k| {
-                std::iter::repeat_n(operators.iter().copied(), k)
-                    .multi_cartesian_product()
-                    .collect()
-            })
-            .collect()
-    }
-    fn check_oper_set(cal: &Calibration, oper_set: &[Operator]) -> bool {
-        let accum = oper_set
-            .iter()
-            .zip(cal.numbers.iter().skip(1))
-            .fold(cal.numbers[0], |accum, (oper, val)| oper.exec(accum, *val));
-        accum == cal.result
-    }
     fn possible(&self, operators: &[Operator]) -> u64 {
-        let operator_sets = Calibrations::make_operator_sets(operators, self.longest_cal);
         self.cals
             .par_iter()
-            .map(|cal| {
-                let n_opers = cal.numbers.len() - 1;
-                if operator_sets[n_opers]
-                    .par_iter()
-                    .find_any(|oper_set| Self::check_oper_set(cal, oper_set))
-                    .is_some()
-                {
-                    return cal.result;
-                }
-                0
-            })
+            .map(|cal| eval_calibration(operators, cal.result, cal.numbers[0], &cal.numbers[1..]))
+            .map(|result| result.unwrap_or(0))
             .sum()
     }
 }
 
+fn eval_calibration(operators: &[Operator], expect: u64, left: u64, right: &[u64]) -> Option<u64> {
+    if left > expect {
+        // all operations make the number larger, so this branch is hopeless, early exit
+        return None;
+    }
+    if right.is_empty() {
+        // base case - no further operations
+        if left == expect {
+            return Some(left);
+        } else {
+            return None;
+        }
+    }
+    operators
+        .iter()
+        .map(|oper| eval_calibration(operators, expect, oper.exec(left, right[0]), &right[1..]))
+        .find_map(|result| result)
+}
+
 // PROBLEM 1 solution
 #[aoc(day7, part1)]
 pub fn part1(cals: &Calibrations) -> u64 {
-    let operators = [Operator::Add, Operator::Multiply];
+    let operators = [Operator::Multiply, Operator::Add];
     cals.possible(&operators)
 }
 
 // PROBLEM 2 solution
 #[aoc(day7, part2)]
 pub fn part2(cals: &Calibrations) -> u64 {
-    let operators = [Operator::Add, Operator::Multiply, Operator::Concatenate];
+    let operators = [Operator::Multiply, Operator::Add, Operator::Concatenate];
     cals.possible(&operators)
 }
 

src/lib.rs

@@ -12,5 +12,6 @@ pub mod day9;
 pub mod day10;
 pub mod day11;
 pub mod day12;
+pub mod day13;
 
 aoc_lib! { year = 2024 }

src/main.rs

@@ -0,0 +1,3 @@
+use aoc_runner_derive::aoc_main;
+
+aoc_main!{ lib = aoc2024 }