day 12 part 2: too slow bruteforce attempt

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(())
 }