From b5185d38b2479389279367d1887e9f4b6909ae0a Mon Sep 17 00:00:00 2001
From: Dominic <git@msrd0.de>
Date: Wed, 13 Dec 2023 00:15:49 +0100
Subject: [PATCH] day 12 part 2: too slow bruteforce attempt

---
 Cargo.lock       | 75 ++++++++++++++++++++++++++++++++++++++++++++++++
 Cargo.toml       |  1 +
 src/bin/day12.rs | 28 ++++++++++++++++++
 3 files changed, 104 insertions(+)

diff --git a/Cargo.lock b/Cargo.lock
index 64b3d2c..4e64d89 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -37,6 +37,7 @@ dependencies = [
  "indexmap",
  "itertools",
  "paste",
+ "rayon",
 ]
 
 [[package]]
@@ -49,6 +50,12 @@ dependencies = [
  "yansi",
 ]
 
+[[package]]
+name = "autocfg"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
+
 [[package]]
 name = "bit-vec"
 version = "0.6.3"
@@ -80,6 +87,39 @@ dependencies = [
  "stacker",
 ]
 
+[[package]]
+name = "crossbeam-deque"
+version = "0.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ce6fd6f855243022dcecf8702fef0c297d4338e226845fe067f6341ad9fa0cef"
+dependencies = [
+ "cfg-if",
+ "crossbeam-epoch",
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-epoch"
+version = "0.9.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae211234986c545741a7dc064309f67ee1e5ad243d0e48335adc0484d960bcc7"
+dependencies = [
+ "autocfg",
+ "cfg-if",
+ "crossbeam-utils",
+ "memoffset",
+ "scopeguard",
+]
+
+[[package]]
+name = "crossbeam-utils"
+version = "0.8.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a22b2d63d4d1dc0b7f1b6b2747dd0088008a9be28b6ddf0b1e7d335e3037294"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "either"
 version = "1.9.0"
@@ -127,6 +167,15 @@ version = "0.2.150"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "89d92a4743f9a61002fae18374ed11e7973f530cb3a3255fb354818118b2203c"
 
+[[package]]
+name = "memoffset"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a634b1c61a95585bd15607c6ab0c4e5b226e695ff2800ba0cdccddf208c406c"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.18.0"
@@ -166,6 +215,32 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "rayon"
+version = "1.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c27db03db7734835b3f53954b534c91069375ce6ccaa2e065441e07d9b6cdb1"
+dependencies = [
+ "either",
+ "rayon-core",
+]
+
+[[package]]
+name = "rayon-core"
+version = "1.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ce3fb6ad83f861aac485e76e1985cd109d9a3713802152be56c3b1f0e0658ed"
+dependencies = [
+ "crossbeam-deque",
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "scopeguard"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
+
 [[package]]
 name = "stacker"
 version = "0.1.15"
diff --git a/Cargo.toml b/Cargo.toml
index 1227dce..60e5afd 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,3 +12,4 @@ chumsky = "0.9"
 indexmap = "2"
 itertools = "0.12"
 paste = "1"
+rayon = "1.8"
diff --git a/src/bin/day12.rs b/src/bin/day12.rs
index 38e8642..f20da63 100644
--- a/src/bin/day12.rs
+++ b/src/bin/day12.rs
@@ -2,6 +2,7 @@
 
 use aoc23::read;
 use chumsky::{prelude::*, text::int};
+use rayon::iter::{IntoParallelRefIterator as _, ParallelIterator as _};
 
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 enum Cell {
@@ -105,5 +106,32 @@ fn main() -> anyhow::Result<()> {
 			.sum::<u64>()
 	);
 
+	println!(
+		"{}",
+		grid.par_iter()
+			.map(|row| {
+				let cells: Vec<Cell> = row
+					.cells
+					.iter()
+					.chain(row.cells.iter())
+					.chain(row.cells.iter())
+					.chain(row.cells.iter())
+					.chain(row.cells.iter())
+					.copied()
+					.collect();
+				let expected: Vec<u32> = row
+					.expected
+					.iter()
+					.chain(row.expected.iter())
+					.chain(row.expected.iter())
+					.chain(row.expected.iter())
+					.chain(row.expected.iter())
+					.copied()
+					.collect();
+				combinations(None, &cells, 0, &expected)
+			})
+			.sum::<u64>()
+	);
+
 	Ok(())
 }