2024-01

crates/core/benches/benchmark.rs

@@ -4,7 +4,7 @@ use std::fs::read_to_string;
 
 pub fn criterion_benchmark(c: &mut Criterion) {
     #![allow(clippy::unwrap_used)]
-    for year in 2015..=2023 {
+    for year in 2015..=2024 {
         let start_day = 1;
         let end_day = 25;
         for day in start_day..=end_day {

crates/core/src/year2024/day01.rs

@@ -1,18 +1,50 @@
-use crate::input::Input;
+use crate::{
+    common::array_stack::ArrayStack,
+    input::{on_error, Input},
+};
 
-pub const fn solve(_input: &Input) -> Result<u32, String> {
-    Ok(0)
+pub fn solve(input: &Input) -> Result<u64, String> {
+    let mut left_list = ArrayStack::<1024, u32>::new();
+    let mut right_list = ArrayStack::<1024, u32>::new();
+
+    for line in input.text.lines() {
+        let (l, r) = line.split_once("   ").ok_or_else(on_error)?;
+        left_list.push(l.parse().map_err(|_| on_error())?)?;
+        right_list.push(r.parse().map_err(|_| on_error())?)?;
+    }
+
+    Ok(if input.is_part_one() {
+        right_list.slice_mut().sort_unstable();
+        left_list.slice_mut().sort_unstable();
+        left_list
+            .slice()
+            .iter()
+            .zip(right_list.slice().iter())
+            .map(|(l, &r)| l.abs_diff(r))
+            .sum::<u32>() as u64
+    } else {
+        left_list
+            .slice()
+            .iter()
+            .map(|&l| u64::from(l) * right_list.slice().iter().filter(|&&r| r == l).count() as u64)
+            .sum::<u64>()
+    })
 }
 
 #[test]
 pub fn tests() {
     use crate::input::{test_part_one_no_allocations, test_part_two_no_allocations};
 
-    let test_input = "";
-    test_part_one_no_allocations!(test_input => 0);
-    test_part_two_no_allocations!(test_input => 0);
+    let test_input = "3   4
+4   3
+2   5
+1   3
+3   9
+3   3";
+    test_part_one_no_allocations!(test_input => 11);
+    test_part_two_no_allocations!(test_input => 31);
 
     let real_input = include_str!("day01_input.txt");
-    test_part_one_no_allocations!(real_input => 0);
-    test_part_two_no_allocations!(real_input => 0);
+    test_part_one_no_allocations!(real_input => 1_882_714);
+    test_part_two_no_allocations!(real_input => 19_437_052);
 }