AoC 2025 Day 2 - rust

Author: pareronia

README.md

@@ -13,7 +13,7 @@
 | python3 | [✓](src/main/python/AoC2025_01.py) | [✓](src/main/python/AoC2025_02.py) | [✓](src/main/python/AoC2025_03.py) | [✓](src/main/python/AoC2025_04.py) | [✓](src/main/python/AoC2025_05.py) | [✓](src/main/python/AoC2025_06.py) | [✓](src/main/python/AoC2025_07.py) | [✓](src/main/python/AoC2025_08.py) | [✓](src/main/python/AoC2025_09.py) | [✓](src/main/python/AoC2025_10.py) | [✓](src/main/python/AoC2025_11.py) | [✓](src/main/python/AoC2025_12.py) |
 | java | [✓](src/main/java/AoC2025_01.java) | [✓](src/main/java/AoC2025_02.java) | [✓](src/main/java/AoC2025_03.java) | [✓](src/main/java/AoC2025_04.java) | [✓](src/main/java/AoC2025_05.java) | [✓](src/main/java/AoC2025_06.java) | [✓](src/main/java/AoC2025_07.java) | [✓](src/main/java/AoC2025_08.java) | [✓](src/main/java/AoC2025_09.java) | [✓](src/main/java/AoC2025_10.java) | [✓](src/main/java/AoC2025_11.java) | [✓](src/main/java/AoC2025_12.java) |
 | bash | [✓](src/main/bash/AoC2025_01.sh) | [✓](src/main/bash/AoC2025_02.sh) | [✓](src/main/bash/AoC2025_03.sh) | [✓](src/main/bash/AoC2025_04.sh) | [✓](src/main/bash/AoC2025_05.sh) | [✓](src/main/bash/AoC2025_06.sh) | [✓](src/main/bash/AoC2025_07.sh) | | | | [✓](src/main/bash/AoC2025_11.sh) | [✓](src/main/bash/AoC2025_12.sh) |
-| rust | [✓](src/main/rust/AoC2025_01/src/main.rs) | | | | | | | | | | | |
+| rust | [✓](src/main/rust/AoC2025_01/src/main.rs) | [✓](src/main/rust/AoC2025_02/src/main.rs) | | | | | | | | | | |
 <!-- @END:ImplementationsTable:2025@ -->
 
 ## 2024

src/main/rust/AoC2025_02/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "AoC2025_02"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+aoc = { path = "../aoc" }

src/main/rust/AoC2025_02/src/main.rs

@@ -0,0 +1,108 @@
+#![allow(non_snake_case)]
+
+use aoc::Puzzle;
+use std::ops::RangeInclusive;
+
+enum Mode {
+ ExactlyOnce,
+ AtLeastOnce,
+}
+
+impl Mode {
+ fn check(&self, n: u64) -> bool {
+ fn sub_check(s: &str, sub_len: usize) -> bool {
+ let sz = s.len();
+ if !sz.is_multiple_of(sub_len) {
+ return false;
+ }
+ let sub = &s[..sub_len];
+ for i in (sub_len..sz).step_by(sub_len) {
+ if !s[i..].starts_with(sub) {
+ return false;
+ }
+ }
+ true
+ }
+
+ let s = n.to_string();
+ match self {
+ Mode::ExactlyOnce => {
+ s.len().is_multiple_of(2) && sub_check(&s, s.len() / 2)
+ }
+ Mode::AtLeastOnce => {
+ for i in 1..=s.len().div_euclid(2) {
+ if sub_check(&s, i) {
+ return true;
+ }
+ }
+ false
+ }
+ }
+ }
+}
+
+struct AoC2025_02;
+
+impl AoC2025_02 {
+ fn solve(&self, ranges: &[RangeInclusive<u64>], mode: Mode) -> u64 {
+ ranges
+ .iter()
+ .flat_map(|rng| rng.clone().step_by(1))
+ .filter(|n| mode.check(*n))
+ .sum()
+ }
+}
+
+impl aoc::Puzzle for AoC2025_02 {
+ type Input = Vec<RangeInclusive<u64>>;
+ type Output1 = u64;
+ type Output2 = u64;
+
+ aoc::puzzle_year_day!(2025, 2);
+
+ fn parse_input(&self, lines: Vec<String>) -> Self::Input {
+ lines[0]
+ .split(',')
+ .map(|sp| {
+ let (lo, hi) = sp.split_once('-').unwrap();
+ RangeInclusive::new(
+ lo.parse::<u64>().unwrap(),
+ hi.parse::<u64>().unwrap(),
+ )
+ })
+ .collect::<Vec<_>>()
+ }
+
+ fn part_1(&self, ranges: &Self::Input) -> Self::Output1 {
+ self.solve(ranges, Mode::ExactlyOnce)
+ }
+
+ fn part_2(&self, ranges: &Self::Input) -> Self::Output2 {
+ self.solve(ranges, Mode::AtLeastOnce)
+ }
+
+ fn samples(&self) {
+ aoc::puzzle_samples! {
+ self, part_1, TEST, 1227775554_u64,
+ self, part_2, TEST, 4174379265_u64
+ };
+ }
+}
+
+fn main() {
+ AoC2025_02 {}.run(std::env::args());
+}
+
+const TEST: &str = "11-22,95-115,998-1012,1188511880-1188511890,222220-222224,\
+ 1698522-1698528,446443-446449,38593856-38593862,\
+ 565653-565659,824824821-824824827,2121212118-2121212124";
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+
+ #[test]
+ pub fn samples() {
+ AoC2025_02 {}.samples();
+ }
+}