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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;
fn run(
mut pos: (i32, i32),
m: &Vec<Vec<bool>>,
) -> (bool, HashSet<(i32, i32)>, HashSet<((i32, i32), (i32, i32))>) {
let mut hs: HashSet<(i32, i32)> = HashSet::new();
let mut hs2: HashSet<((i32, i32), (i32, i32))> = HashSet::new();
let mut circ = false;
let mut dir = [(0, -1), (1, 0), (0, 1), (-1, 0)];
loop {
hs.insert(pos);
hs2.insert((pos, dir[0]));
let new_pos = (pos.0 + dir[0].0, pos.1 + dir[0].1);
if hs2.contains(&(new_pos, dir[0])) {
circ = true;
break;
}
if new_pos.0 < 0
|| new_pos.1 < 0
|| new_pos.0 >= m[0].len().try_into().unwrap()
|| new_pos.1 >= m.len().try_into().unwrap()
{
break;
}
if m[new_pos.1 as usize][new_pos.0 as usize] {
pos = new_pos;
continue;
} else {
dir.rotate_left(1);
}
}
return (circ, hs, hs2);
}
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 pos: (i32, i32) = (0, 0);
let mut m: Vec<Vec<bool>> = Vec::new();
for (y, line) in lines.enumerate() {
let mut row = Vec::new();
for (x, c) in line.chars().enumerate() {
row.push(if c == '#' { false } else { true });
if c == '^' {
pos = (x.try_into().unwrap(), y.try_into().unwrap());
}
}
m.push(row);
}
let (circ, hs, hs2) = run(pos, &m);
let res1 = hs.len();
let mut res2 = 0;
for (x, y) in hs {
let mut m2 = m.clone();
m2[y as usize][x as usize] = false;
let (circ, hs, hs2) = run(pos, &m2);
if circ {
res2 += 1;
}
}
println!("res1: {}", res1);
println!("res2: {}", res2);
assert_eq!(res1, 5531);
assert_eq!(res2, 2165);
}
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