Solve part 1 :)

Author: caass

Diff for: src/2024/01.rs

@@ -1,3 +1,43 @@
+use eyre::{eyre, OptionExt, Report, Result};
+use rayon::prelude::*;
+
 use crate::meta::Problem;
 
-pub const HISTORIAN_HYSTERIA: Problem = Problem::unsolved();
+pub const HISTORIAN_HYSTERIA: Problem = Problem::partially_solved(&|input| -> Result<usize> {
+    let (lhs, rhs) = input
+        .lines()
+        .map(|line| {
+            let mut iter = line.split_ascii_whitespace();
+            let a_str = iter.next().ok_or_eyre("empty line")?;
+            let b_str = iter
+                .next()
+                .ok_or_else(|| eyre!("No whitespace on line: \"{line}\""))?;
+
+            debug_assert!(iter.next().is_none());
+
+            let a = a_str.parse()?;
+            let b = b_str.parse()?;
+
+            Ok::<(usize, usize), Report>((a, b))
+        })
+        .try_fold((Vec::new(), Vec::new()), |(mut lhs, mut rhs), res| {
+            let (a, b) = res?;
+
+            lhs.push(a);
+            rhs.push(b);
+
+            Ok::<_, Report>((lhs, rhs))
+        })
+        .map(|(mut lhs, mut rhs)| {
+            lhs.sort_unstable();
+            rhs.sort_unstable();
+
+            (lhs, rhs)
+        })?;
+
+    Ok(lhs
+        .into_par_iter()
+        .zip(rhs)
+        .map(|(a, b)| a.abs_diff(b))
+        .sum())
+});

Diff for: tests/integration.rs

@@ -36,7 +36,11 @@ util::tests! {
         6:  ["tzstqsua", "myregdnr"],
         7:  [115, 231],
         8:  [115, "EFEYKFRFIJ"],
-        9:  [102239, 10780403063u64]
+        9:  [102239, #[ignore = "slow implementation"] 10780403063u64]
+    },
+
+    2024: {
+        1: [2000468]
     }
 }