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#![allow(dead_code)]
#![allow(unused_variables)]
#![allow(unused_mut)]
use std::env;
use std::fs::File;
use std::io::Read;
#[derive(Debug, PartialEq, Clone)]
struct Machine {
ax: i128,
ay: i128,
bx: i128,
by: i128,
px: i128,
py: i128,
}
fn solve(m: &Machine) -> Option<i128> {
let mut min_price = None;
for a in 0..100 {
for b in 0..100 {
let x = a * m.ax + b * m.bx;
let y = a * m.ay + b * m.by;
if x == m.px && y == m.py {
let price = a * 3 + b * 1;
if min_price == None || price < min_price.unwrap() {
min_price = Some(price);
}
}
}
}
min_price
}
fn solve2(m: &Machine) -> Option<i128> {
let n1 = m.px * m.ay - m.py * m.ax;
let n2 = m.bx * m.ay - m.by * m.ax;
if n1 % n2 != 0 {
return None;
}
let b = n1 / n2;
let n1 = m.px - b * m.bx;
let n2 = m.ax;
if n1 % n2 != 0 {
return None;
}
let a = n1 / n2;
Some(a * 3 + b)
}
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 para = content.trim_end().split("\n\n");
let mut mvec: Vec<Machine> = Vec::new();
for lines in para {
let mut m: Machine = Machine {
ax: 0,
ay: 0,
bx: 0,
by: 0,
px: 0,
py: 0,
};
let (s, rest) = lines.split_once("X+").unwrap();
let (s, rest) = rest.split_once(",").unwrap();
m.ax = s.parse().unwrap();
let (s, rest) = rest.split_once("Y+").unwrap();
let (s, rest) = rest.split_once("\n").unwrap();
m.ay = s.parse().unwrap();
let (s, rest) = rest.split_once("X+").unwrap();
let (s, rest) = rest.split_once(",").unwrap();
m.bx = s.parse().unwrap();
let (s, rest) = rest.split_once("Y+").unwrap();
let (s, rest) = rest.split_once("\n").unwrap();
m.by = s.parse().unwrap();
let (s, rest) = rest.split_once("X=").unwrap();
let (s, rest) = rest.split_once(",").unwrap();
m.px = s.parse().unwrap();
let (s, rest) = rest.split_once("Y=").unwrap();
m.py = rest.parse().unwrap();
mvec.push(m);
}
let mut res1 = 0;
let mut res2 = 0;
for m in &mvec {
let p1 = solve(m);
if let Some(val) = p1 {
//println!("{}", val);
res1 += val;
}
let m2: Machine = Machine {
ax: m.ax,
ay: m.ay,
bx: m.bx,
by: m.by,
px: m.px + 10000000000000,
py: m.py + 10000000000000,
};
let p2 = solve2(&m2);
if let Some(val) = p2 {
//println!("{}", val);
res2 += val;
}
}
println!("res1: {}", res1);
println!("res2: {}", res2);
assert_eq!(res1, 29187);
assert_eq!(res2, 99968222587852);
}
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