Stefan Müller
46 lines
1.3 KiB
Rust
46 lines
1.3 KiB
Rust
use crate::solvers::Solver;
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use memchr::{memchr, memchr_iter};
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use std::io::BufRead;
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pub struct Laboratories {}
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impl Laboratories {
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const START_CHAR: u8 = b'S';
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const SPLITTER_CHAR: u8 = b'^';
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fn start_beam(line: &str) -> Vec<u64> {
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let mut beams = vec![0; line.len()];
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if let Some(s) = memchr(Self::START_CHAR, line.as_bytes()) {
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beams[s] = 1;
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}
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beams
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}
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fn split_beams(line: &str, mut beams: Vec<u64>, mut splits: u64) -> (Vec<u64>, u64) {
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for s in memchr_iter(Self::SPLITTER_CHAR, line.as_bytes()) {
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if beams[s] > 0 {
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splits += 1;
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beams[s - 1] += beams[s];
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beams[s + 1] += beams[s];
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beams[s] = 0;
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}
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}
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(beams, splits)
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}
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}
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impl Solver for Laboratories {
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const PUZZLE_INDEX: u8 = 7;
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const PUZZLE_NAME: &'static str = "Laboratories";
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fn process_data<R: BufRead>(&self, mut reader: R) -> (u64, u64) {
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let line = reader.by_ref().lines().next().unwrap().unwrap();
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let mut beams = Self::start_beam(&line);
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let mut splits = 0;
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for line in reader.lines().map_while(Result::ok) {
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(beams, splits) = Self::split_beams(&line, beams, splits);
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}
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(splits, beams.iter().sum())
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}
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}
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