feat(2025): refactor day 2

Refactored Day 2 of 2025 to use the common framework. Successfully migrated solution and integrated it into the runner.

Author: markkovari

2025/inputs/2/prod.txt

@@ -0,0 +1 @@
+9595822750-9596086139,1957-2424,88663-137581,48152-65638,12354817-12385558,435647-489419,518494-609540,2459-3699,646671-688518,195-245,295420-352048,346-514,8686839668-8686892985,51798991-51835611,8766267-8977105,2-17,967351-995831,6184891-6331321,6161577722-6161678622,912862710-913019953,6550936-6625232,4767634976-4767662856,2122995-2257010,1194-1754,779-1160,22-38,4961-6948,39-53,102-120,169741-245433,92902394-92956787,531-721,64-101,15596-20965,774184-943987,8395-11781,30178-47948,94338815-94398813

2025/rust/src/day02.rs

@@ -0,0 +1,50 @@
+use aoc_rust_common::Solution;
+use std::fmt::Display;
+use std::str::FromStr;
+
+pub struct Day02;
+
+type Id = u64;
+
+#[derive(Debug, Clone, Copy)]
+struct Range { lower: Id, upper: Id }
+
+impl FromStr for Range {
+    type Err = ();
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let parts: Vec<Id> = s.split('-').map(|p| p.parse().unwrap()).collect();
+        Ok(Range { lower: parts[0], upper: parts[1] })
+    }
+}
+
+fn is_double(n: Id) -> bool {
+    let s = n.to_string();
+    let len = s.len();
+    len % 2 == 0 && s[..len/2] == s[len/2..]
+}
+
+fn is_at_least_double(n: Id) -> bool {
+    let s = n.to_string();
+    let len = s.len();
+    (1..len).filter(|d| len % d == 0 && len / d >= 2).any(|d| {
+        let pattern = &s[..d];
+        s.as_bytes().chunks(d).all(|c| c == pattern.as_bytes())
+    })
+}
+
+impl Solution for Day02 {
+    fn year(&self) -> u32 { 2025 }
+    fn day(&self) -> u32 { 2 }
+
+    fn part1(&self, input: &str) -> Box<dyn Display> {
+        let ranges: Vec<Range> = input.trim().split(',').map(|s| s.parse().unwrap()).collect();
+        let sum: Id = ranges.iter().flat_map(|r| (r.lower..=r.upper).filter(|&n| is_double(n))).sum();
+        Box::new(sum)
+    }
+
+    fn part2(&self, input: &str) -> Box<dyn Display> {
+        let ranges: Vec<Range> = input.trim().split(',').map(|s| s.parse().unwrap()).collect();
+        let sum: Id = ranges.iter().flat_map(|r| (r.lower..=r.upper).filter(|&n| is_at_least_double(n))).sum();
+        Box::new(sum)
+    }
+}

2025/rust/src/main.rs

@@ -1,7 +1,10 @@
 mod day01;
+mod day02;
 use aoc_rust_common::run_solution;
 use day01::Day01;
+use day02::Day02;
 
 fn main() {
     run_solution(Day01);
+    run_solution(Day02);
 }