Files
aoc_2018/src/tasks/day12.rs
Johannes Schaefer 2fa6c40f33 day12 part 1
2018-12-14 14:09:57 +01:00

55 lines
1.4 KiB
Rust

use crate::utils;
use std::collections::HashMap;
use std::ops::Add;
pub fn task1() {
let input = utils::read_file("input/day12.txt");
let mut input = input.lines();
let num_generations = 20;
let mut state: Vec<char> = "."
.repeat(num_generations)
.add(&input.next().unwrap()[15..])
.add(&".".repeat(num_generations + 2))
.chars()
.collect();
let mut transformations: HashMap<String, char> = HashMap::new();
input.next();
for line in input {
let key = line.split(" => ").nth(0).unwrap();
transformations.insert(key.to_string(), line.chars().last().unwrap());
}
for _ in 0..num_generations {
println!("{}", state.iter().collect::<String>());
let mut new_state = state.clone();
for (i, c) in new_state[2..state.len() - 2].iter_mut().enumerate() {
let next = transformations.get(&state[i..i + 5].iter().collect::<String>());
if let Some(cc) = next {
*c = *cc;
} else {
*c = '.';
}
}
state = new_state;
}
println!("{}", state.iter().collect::<String>());
let sum: isize = state
.iter()
.enumerate()
.map(|(i, c)| {
if *c == '#' {
i as isize - (num_generations as isize)
} else {
0
}
})
.sum();
println!("Result: {}", sum);
}