117 lines
3.4 KiB
Rust
117 lines
3.4 KiB
Rust
use std::fs::File;
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use std::io::{self, BufRead};
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use std::path::Path;
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use std::collections::HashSet;
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#[derive(Debug)]
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struct Cell {
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altitude: u8,
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score: Option<u32>,
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}
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impl Cell {
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pub fn new(altitude: u8) -> Self {
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Self {
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altitude,
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score: None,
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}
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}
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}
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fn print_map(map: &Vec<Vec<Cell>>) {
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for y in map.iter() {
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for x in y.iter() {
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let c;
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match x.score {
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Some(n) => {
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let m = (n % 62) as u8;
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if m < 26 {
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c = m + b'a';
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}
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else if m < 52 {
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c = m + b'A' - 26;
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}
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else {
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c = m + b'0' - 52;
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}
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},
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None => c = b'#'
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};
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print!("{}", c as char);
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}
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println!("");
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}
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}
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fn main() {
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let file_path = String::from("input");
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let mut map = Vec::<Vec<Cell>>::new();
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let mut start_coor: (usize, usize) = (0, 0);
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let mut end_coor: (usize, usize) = (0, 0);
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println!("In file {}", file_path);
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if let Ok(lines) = read_lines(file_path) {
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// Consumes the iterator, returns an (Optional) String
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for (y, line) in lines.enumerate() {
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if let Ok(ip) = line {
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map.push(ip.bytes().enumerate().map(|(x, byte)| match byte {
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b'a'..=b'z' => Cell::new(byte - b'a'),
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b'S' => {
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start_coor = (x, y);
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Cell::new(0)
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},
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b'E' => {
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end_coor = (x, y);
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Cell::new(25)
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}
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_ => panic!("Parse error"),
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}).collect());
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}
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}
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}
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let height = map.len();
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let width = map[0].len();
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let mut cursors = vec![start_coor];
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let mut score = 0;
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while !cursors.is_empty() {
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let mut new_cursors = HashSet::<(usize, usize)>::new();
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for cursor in cursors {
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let (x, y) = cursor;
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let altitude = map[y][x].altitude;
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match map[y][x].score {
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Some(_) => (),
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None => {
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map[y][x].score = Some(score);
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if x + 1 < width && altitude + 1 >= map[y][x + 1].altitude {
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new_cursors.insert((x + 1, y));
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}
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if x > 0 && altitude + 1 >= map[y][x - 1].altitude {
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new_cursors.insert((x - 1, y));
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}
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if y + 1 < height && altitude + 1 >= map[y + 1][x].altitude {
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new_cursors.insert((x, y + 1));
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}
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if y > 0 && altitude + 1 >= map[y - 1][x].altitude {
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new_cursors.insert((x, y - 1));
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}
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},
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};
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}
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score += 1;
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cursors = Vec::<(usize, usize)>::new();
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for cursor in new_cursors {
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cursors.push(cursor);
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}
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}
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print_map(&map);
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println!("{}", map[end_coor.1][end_coor.0].score.unwrap());
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}
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fn read_lines<P>(filename: P) -> io::Result<io::Lines<io::BufReader<File>>>
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where P: AsRef<Path>, {
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let file = File::open(filename)?;
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Ok(io::BufReader::new(file).lines())
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}
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