39 lines
No EOL
1.2 KiB
Rust
39 lines
No EOL
1.2 KiB
Rust
use std::{fs::read_to_string, collections::HashMap};
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fn parse_input() -> (String, HashMap<String, (String, String)>) {
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let lines = read_to_string("input.txt").unwrap().lines().map(|line| {
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String::from(line)
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}).collect::<Vec<_>>();
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let instr = lines[0].trim();
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let mut mapping: HashMap<String, (String, String)> = HashMap::new();
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for line in &lines[2..] {
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let (key, instructions) = line.split_once('=').unwrap();
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let (left, right) = instructions.trim().split_once(' ').unwrap();
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mapping.insert(String::from(key.trim()), (String::from(&left[1..4]), String::from(&right[..3])));
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}
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(String::from(instr), mapping)
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}
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fn main() {
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let (instructions, mapping) = parse_input();
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let mut position = String::from("AAA");
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let mut steps = 0;
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let mut caret = 0;
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loop {
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if position == "ZZZ" {
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break;
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}
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position = if instructions.as_bytes()[caret] == b'L' { mapping[&position].0.clone() } else {mapping[&position].1.clone() };
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caret = if caret + 1 == instructions.len() { 0 } else { caret + 1 };
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steps += 1;
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}
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println!("Number of steps taken: {}", steps);
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} |