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#![allow(dead_code)]
#![allow(unused_variables)]
#![allow(unused_mut)]
use std::collections::HashSet;
use std::env;
use std::fs::File;
use std::io::Read;
// #[derive(Hash, Eq, Debug, PartialEq, Clone, Copy)]
// enum Field {
// Empty,
// Rock,
// Start,
// }
type Matrix<T> = Vec<Vec<T>>;
fn bfs(steps: usize, x0: usize, y0: usize, m: &Matrix<bool>) -> usize {
let mut hs: HashSet<(usize, usize)> = HashSet::new();
let mut hs_next: HashSet<(usize, usize)> = HashSet::new();
hs.insert((x0, y0));
for s in 0..steps {
for (x, y) in hs {
if x + 1 < m[0].len() && m[y][x + 1] {
hs_next.insert((x + 1, y));
}
if x as i32 - 1 >= 0 && m[y][x - 1] {
hs_next.insert((x - 1, y));
}
if y + 1 < m.len() && m[y + 1][x] {
hs_next.insert((x, y + 1));
}
if y as i32 - 1 >= 0 && m[y - 1][x] {
hs_next.insert((x, y - 1));
}
}
hs = hs_next;
hs_next = HashSet::new();
}
return hs.len();
}
fn main() {
let args: Vec<String> = env::args().collect();
let filename = if args.len() == 1 {
"in/".to_owned() + args[0].split('/').last().unwrap() + ".pzl"
} else {
args[1].clone()
};
let mut f = File::open(filename).expect("cannot open file");
let mut content = String::new();
f.read_to_string(&mut content).expect("cannot read file");
let lines = content.trim_end().split("\n");
let mut x0: usize = 0;
let mut y0: usize = 0;
let mut m: Matrix<bool> = Vec::new();
for (y, line) in lines.enumerate() {
let mut r: Vec<bool> = Vec::new();
for (x, c) in line.chars().enumerate() {
match c {
'.' => r.push(true),
'#' => r.push(false),
'S' => {
r.push(true);
x0 = x;
y0 = y;
}
_ => panic!(),
};
}
m.push(r);
}
let res1 = 0;
// let res1 = bfs(64, x0, y0, &m);
let steps = 26501365;
let mut res2 = bfs(264, x0, y0, &m);
println!("res1: {}", res1);
println!("res2: {}", res2);
}
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