1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
|
use std::io;
use std::io::BufRead;
use std::collections::HashSet;
use crate::device::*;
#[allow(dead_code)]
fn optimise(mut instrs: Vec<Instr>, ip_reg: usize) -> Vec<Instr> {
for i in 0..instrs.len() {
instrs[i].inline_reg(ip_reg, Oper::Num(i));
}
instrs
}
#[allow(dead_code)]
fn run_program(instrs: &[Instr], r0: usize, ip_reg: usize) -> usize {
let mut m = Machine { regs: [r0, 0, 0, 0, 0, 0] };
m.exec_program(&instrs, ip_reg);
m.regs[0]
}
pub fn main<T: BufRead>(reader: T) -> io::Result<(String, String)> {
let (ip_reg, instrs) = parse_program(reader)?;
let instrs = optimise(instrs, ip_reg);
// for instr in &instrs { println!("{}", instr); }
let part1;
let mut ip = 0;
let mut m = Machine { regs: [0, 0, 0, 0, 0, 0] };
loop {
assert!(ip < instrs.len());
if ip == 28 {
part1 = m.regs[4];
break;
}
m.regs[ip_reg] = ip;
m.exec(&instrs[ip]);
ip = m.regs[ip_reg] + 1;
}
let mut part2 = None;
let mut seen_machines = HashSet::new();
let mut seen_values = HashSet::new();
loop {
assert!(ip < instrs.len());
if ip == 28 {
// println!("{:?}", m);
if seen_machines.contains(&m) {
break;
}
seen_machines.insert(m.clone());
if !seen_values.contains(&m.regs[4]) {
part2 = Some(m.regs[4]);
seen_values.insert(m.regs[4]);
}
}
m.regs[ip_reg] = ip;
m.exec(&instrs[ip]);
ip = m.regs[ip_reg] + 1;
}
Ok((part1.to_string(), part2.unwrap().to_string()))
}
|
