Year 2024 Day 25

Author: maneatingape

README.md

@@ -96,6 +96,7 @@ Performance is reasonable even on older hardware, for example a 2011 MacBook Pro
 | 22 | [Monkey Market](https://adventofcode.com/2024/day/22) | [Source](src/year2024/day22.rs) | 1350 |
 | 23 | [LAN Party](https://adventofcode.com/2024/day/23) | [Source](src/year2024/day23.rs) | 43 |
 | 24 | [Crossed Wires](https://adventofcode.com/2024/day/24) | [Source](src/year2024/day24.rs) | 36 |
+| 25 | [Code Chronicle](https://adventofcode.com/2024/day/25) | [Source](src/year2024/day25.rs) | 12 |
 
 ## 2023
 

benches/benchmark.rs

@@ -88,5 +88,5 @@ benchmark!(year2023
 
 benchmark!(year2024
     day01, day02, day03, day04, day05, day06, day07, day08, day09, day10, day11, day12, day13,
-    day14, day15, day16, day17, day18, day19, day20, day21, day22, day23, day24
+    day14, day15, day16, day17, day18, day19, day20, day21, day22, day23, day24, day25
 );

src/lib.rs

@@ -68,5 +68,5 @@ library!(year2023 "Restore global snow production."
 
 library!(year2024 "Locate the Chief Historian in time for the big Christmas sleigh launch."
     day01, day02, day03, day04, day05, day06, day07, day08, day09, day10, day11, day12, day13,
-    day14, day15, day16, day17, day18, day19, day20, day21, day22, day23, day24
+    day14, day15, day16, day17, day18, day19, day20, day21, day22, day23, day24, day25
 );

src/main.rs

@@ -138,5 +138,5 @@ run!(year2023
 
 run!(year2024
     day01, day02, day03, day04, day05, day06, day07, day08, day09, day10, day11, day12, day13,
-    day14, day15, day16, day17, day18, day19, day20, day21, day22, day23, day24
+    day14, day15, day16, day17, day18, day19, day20, day21, day22, day23, day24, day25
 );

src/year2024/day25.rs

@@ -0,0 +1,47 @@
+//! # Code Chronicle
+pub fn parse(input: &str) -> &str {
+    input
+}
+
+pub fn part1(input: &str) -> u32 {
+    let mut iter = input.bytes();
+    let mut locks = Vec::with_capacity(250);
+    let mut keys = Vec::with_capacity(250);
+    let mut result = 0;
+
+    loop {
+        let mut bits = 0;
+
+        for _ in 0..41 {
+            let b = iter.next().unwrap();
+            bits = (bits << 1) | (b & 1) as u64;
+        }
+
+        bits &= 0b011111_011111_011111_011111_011111_011111_011111;
+
+        if bits & 0b011111_000000_000000_000000_000000_000000_000000 != 0 {
+            locks.push(bits);
+        } else {
+            keys.push(bits);
+        }
+
+        iter.next();
+        if iter.next().is_none() {
+            break;
+        }
+    }
+
+    for lock in &locks {
+        for key in &keys {
+            if lock & key == 0 {
+                result += 1;
+            }
+        }
+    }
+
+    result
+}
+
+pub fn part2(_input: &str) -> &'static str {
+    "n/a"
+}

tests/test.rs

@@ -81,5 +81,5 @@ test!(year2023
 
 test!(year2024
     day01, day02, day03, day04, day05, day06, day07, day08, day09, day10, day11, day12, day13,
-    day14, day15, day16, day17, day18, day19, day20, day21, day22, day23, day24
+    day14, day15, day16, day17, day18, day19, day20, day21, day22, day23, day24, day25
 );

tests/year2024/day25.rs

@@ -0,0 +1,54 @@
+use aoc::year2024::day25::*;
+
+const EXAMPLE: &str = "\
+#####
+.####
+.####
+.####
+.#.#.
+.#...
+.....
+
+#####
+##.##
+.#.##
+...##
+...#.
+...#.
+.....
+
+.....
+#....
+#....
+#...#
+#.#.#
+#.###
+#####
+
+.....
+.....
+#.#..
+###..
+###.#
+###.#
+#####
+
+.....
+.....
+.....
+#....
+#.#..
+#.#.#
+#####";
+
+#[test]
+fn part1_test() {
+    let input = parse(EXAMPLE);
+    assert_eq!(part1(input), 3);
+}
+
+#[test]
+fn part2_test() {
+    let input = parse(EXAMPLE);
+    assert_eq!(part2(input), "n/a");
+}