From 3ec662bbb1477be34fb14877fa4a549a6bb4bbf7 Mon Sep 17 00:00:00 2001
From: Mike Vink <ivi@vinkies.net>
Date: Thu, 14 Dec 2023 22:32:34 +0100
Subject: add day2

---
 src/bin/day2.rs | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 src/bin/day2.rs

(limited to 'src/bin')

diff --git a/src/bin/day2.rs b/src/bin/day2.rs
new file mode 100644
index 0000000..a007159
--- /dev/null
+++ b/src/bin/day2.rs
@@ -0,0 +1,78 @@
+#![feature(test)]
+use std::error::Error;
+
+const COLORS: [&str; 3] = ["red", "green", "blue"];
+const AMOUNT: [u32; 3] = [12, 13, 14];
+
+// NOTE: probably should just panic, filter_mapping doesn't make much sense if you need the input to be correct.
+fn main() -> Result<(), Box<dyn Error>> {
+    let file = std::fs::read_to_string("input/2/in.txt")?;
+    let cube_lines: Vec<_> = file
+        .lines()
+        .enumerate()
+        .filter_map(|(i, line)| -> Option<(u32, Vec<(usize, u32)>)> {
+            let mut fields = line.split(':');
+            let id: u32 = (i + 1) as u32;
+            let cubes = fields
+                .nth(1)?
+                .split(';')
+                .flat_map(|s| {
+                    s.trim()
+                        .split(",")
+                        .filter_map(|game| {
+                            let mut fields = game.trim().split(" ");
+                            let num: u32 = fields.next()?.parse().ok()?;
+                            let color = fields.next()?;
+                            let c = COLORS.iter().position(|col| *col == color)?;
+                            Some((c, num))
+                        })
+                        .collect::<Vec<_>>()
+                })
+                .collect();
+            Some((id, cubes))
+        })
+        .collect();
+
+    let part1: u32 = cube_lines
+        .iter()
+        .filter_map(|(id, cubes)| {
+            if cubes.iter().all(|(color, num)| *num <= AMOUNT[*color]) {
+                Some(id)
+            } else {
+                None
+            }
+        })
+        .sum();
+    dbg!(part1);
+    let part2: u32 = cube_lines
+        .iter()
+        .map(|(_, cubes)| {
+            cubes
+                .into_iter()
+                .fold([0, 0, 0], |mut acc, (color, num)| {
+                    if acc[*color] < *num {
+                        acc[*color] = *num;
+                    }
+                    acc
+                })
+                .into_iter()
+                .product::<u32>()
+        })
+        .sum();
+    dbg!(part2);
+
+    Ok(())
+}
+
+extern crate test;
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use test::Bencher;
+
+    #[bench]
+    fn other(b: &mut Bencher) {
+        b.iter(|| main());
+    }
+}
-- 
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