my solutions to advent of code
aylac.top
aoc
advent-of-code
1use std::collections::{HashMap, HashSet};
2
3fn main() {
4 let input = include_str!("../../input.txt");
5 let input: Vec<&str> = input.trim().split("\n").collect();
6
7 let combinations: HashMap<String, Vec<String>> = {
8 let mut combinations = HashMap::new();
9 input[..input.len() - 2].iter().for_each(|v| {
10 let v: Vec<&str> = v.split(" ").collect();
11 match v[..] {
12 [original, "=>", target] => {
13 let entry = combinations
14 .entry(original.to_string())
15 .or_insert(Vec::with_capacity(1));
16 entry.push(target.to_string());
17 }
18 _ => panic!("{:?}", v),
19 }
20 });
21 combinations
22 };
23
24 let medicine_mol = input.last().unwrap();
25
26 // part 1
27 {
28 let mol_len = medicine_mol.len();
29 let mut possibilities: HashSet<String> = HashSet::new();
30 for i in 0..mol_len {
31 let (a, b) = medicine_mol.split_at(i);
32 combinations.iter().for_each(|(from, to)| {
33 to.iter().for_each(|to| {
34 possibilities.insert(format!(
35 "{}{}",
36 a,
37 b.replacen(from, to, 1)
38 ));
39 })
40 });
41 }
42 println!("Part 1: {}", possibilities.len() - 1)
43 }
44}