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#![allow(dead_code)]
#![allow(unused_variables)]
#![allow(unused_mut)]
use num::complex::Complex as c;
use num::Complex;
use std::cmp::max;
use std::collections::HashMap;
use std::collections::HashSet;
use std::env;
use std::fs::File;
use std::io::Read;
#[derive(Debug)]
enum Field {
Empty,
Slash,
Backslash,
Vert,
Horiz,
}
type Matrix<T> = Vec<Vec<T>>;
type C32 = Complex<i32>;
fn slash_dir(dir: C32) -> C32 {
if dir.im != 0 {
dir * c::i()
} else {
-dir * c::i()
}
}
fn backslash_dir(dir: C32) -> C32 {
if dir.re != 0 {
dir * c::i()
} else {
-dir * c::i()
}
}
fn rec(mut pos: C32, dir: C32, m: &Matrix<Field>, v: &mut HashMap<(C32, C32), bool>) -> () {
pos += dir;
if !(0 <= pos.re && pos.re < m[0].len() as i32 && 0 <= pos.im && pos.im < m.len() as i32) {
return;
}
if let Some(_) = v.insert((pos, dir), true) {
return;
}
match m[pos.im as usize][pos.re as usize] {
Field::Vert => {
if dir.im != 0 {
rec(pos, dir, m, v);
} else {
rec(pos, dir * c::i(), m, v);
rec(pos, -dir * c::i(), m, v);
}
}
Field::Horiz => {
if dir.re != 0 {
rec(pos, dir, m, v);
} else {
rec(pos, dir * c::i(), m, v);
rec(pos, -dir * c::i(), m, v);
}
}
Field::Slash => rec(pos, slash_dir(dir), m, v),
Field::Backslash => rec(pos, backslash_dir(dir), m, v),
Field::Empty => rec(pos, dir, m, v),
};
}
fn print_energized(e: &HashSet<&C32>, x_len: usize, y_len: usize) {
for y in 0..y_len {
for x in 0..x_len {
if let Some(_) = e.get(&((x as i32) + (y as i32) * c::i())) {
print!("#");
} else {
print!(".");
}
}
println!();
}
}
fn get_energized(pos: C32, dir: C32, m: &Matrix<Field>) -> usize {
let mut visited: HashMap<(C32, C32), bool> = HashMap::new();
rec(pos, dir, m, &mut visited);
let mut energized: HashSet<&C32> = HashSet::new();
for (pos, dir) in visited.keys() {
energized.insert(pos);
}
// print_energized(&energized, m[0].len(), m.len());
return energized.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 m: Matrix<Field> = Vec::new();
for line in lines {
let mut l = Vec::new();
for c in line.chars() {
let a = match c {
'.' => Field::Empty,
'/' => Field::Slash,
'\\' => Field::Backslash,
'|' => Field::Vert,
'-' => Field::Horiz,
_ => panic!(),
};
l.push(a);
}
m.push(l);
}
let mut res1 = get_energized(c::new(-1, 0), c::new(1, 0), &m);
let mut res2 = 0;
for y in 0..m.len() {
res2 = max(res2, get_energized(c::new(-1, y as i32), c::new(1, 0), &m));
res2 = max(
res2,
get_energized(c::new(m[0].len() as i32, y as i32), c::new(-1, 0), &m),
);
}
for x in 0..m[0].len() {
res2 = max(res2, get_energized(c::new(x as i32, -1), c::new(0, 1), &m));
res2 = max(
res2,
get_energized(c::new(m.len() as i32, x as i32), c::new(0, -1), &m),
);
}
println!("res1: {}", res1);
println!("res2: {}", res2);
assert_eq!(res1, 6921);
assert_eq!(res2, 7594);
}
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