My submissions for Advent of Code 2025
adventofcode.com/2025
cherry.computer
rust
aoc
1use std::fs::read_to_string;
2
3fn main() {
4 let invalid_sum: u64 = read_to_string("../input.txt")
5 .expect("failed to open input file")
6 .split(',')
7 .flat_map(|range| {
8 let (first_id, last_id) = range.split_once('-').expect("failed to parse range");
9 let (first_id, last_id): (u64, u64) = (
10 first_id.parse().expect("failed to parse first ID"),
11 last_id.trim_end().parse().expect("failed to parse last ID"),
12 );
13
14 first_id..=last_id
15 })
16 .filter(|id| {
17 let id = id.to_string();
18 let digit_count = id.len();
19 (1..=(digit_count / 2))
20 .any(|pattern_len| id[0..pattern_len].repeat(digit_count / pattern_len) == id)
21 })
22 .sum();
23 println!("The sum of all invalid IDs is {invalid_sum}!")
24}