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use std::collections::HashMap;
use regex::Regex;
fn main() {
let input = advent::read_lines(7);
let mut circuit = Circuit::new(&input);
let signal_a = circuit.lookup_signal("a");
println!("7a: {}", signal_a);
let mut circuit = Circuit::new(&input);
circuit.instructions.insert("b".to_string(), Operation::Direct(Signal::Raw(signal_a)));
let signal_a = circuit.lookup_signal("a");
println!("7b: {}", signal_a);
}
#[derive(Clone)]
enum Signal {
Raw(u16),
Wire(String),
}
impl Signal {
fn new(input: &str) -> Signal {
match input.parse::<u16>() {
Ok(val) => Signal::Raw(val),
Err(_) => Signal::Wire(input.to_string()),
}
}
}
#[derive(Clone)]
enum Operation {
And(Signal, Signal),
Or(Signal, Signal),
Lshift(Signal, u8),
Rshift(Signal, u8),
Not(Signal),
Direct(Signal),
}
struct Circuit {
instructions: HashMap<String, Operation>,
}
impl Circuit {
fn new<T: AsRef<str>>(input: &[T]) -> Circuit {
let re_and = Regex::new(r"^([a-z0-9]+) AND ([a-z0-9]+) -> ([a-z0-9]+)").unwrap();
let re_or = Regex::new(r"^([a-z0-9]+) OR ([a-z0-9]+) -> ([a-z0-9]+)").unwrap();
let re_lshift = Regex::new(r"^([a-z0-9]+) LSHIFT ([0-9]+) -> ([a-z0-9]+)").unwrap();
let re_rshift = Regex::new(r"^([a-z0-9]+) RSHIFT ([0-9]+) -> ([a-z0-9]+)").unwrap();
let re_not = Regex::new(r"^NOT ([a-z0-9]+) -> ([a-z0-9]+)").unwrap();
let re_direct = Regex::new(r"^([a-z0-9]+) -> ([a-z0-9]+)").unwrap();
let mut instructions = HashMap::new();
for line in input {
let (out, operation) = if let Some(cap) = re_and.captures(line.as_ref()) {
let s1 = Signal::new(&cap[1]);
let s2 = Signal::new(&cap[2]);
let out = cap[3].to_string();
(out, Operation::And(s1, s2))
} else if let Some(cap) = re_or.captures(line.as_ref()) {
let s1 = Signal::new(&cap[1]);
let s2 = Signal::new(&cap[2]);
let out = cap[3].to_string();
(out, Operation::Or(s1, s2))
} else if let Some(cap) = re_lshift.captures(line.as_ref()) {
let s1 = Signal::new(&cap[1]);
let val = cap[2].parse::<u8>().unwrap();
let out = cap[3].to_string();
(out, Operation::Lshift(s1, val))
} else if let Some(cap) = re_rshift.captures(line.as_ref()) {
let s1 = Signal::new(&cap[1]);
let val = cap[2].parse::<u8>().unwrap();
let out = cap[3].to_string();
(out, Operation::Rshift(s1, val))
} else if let Some(cap) = re_not.captures(line.as_ref()) {
let s1 = Signal::new(&cap[1]);
let out = cap[2].to_string();
(out, Operation::Not(s1))
} else if let Some(cap) = re_direct.captures(line.as_ref()) {
let s1 = Signal::new(&cap[1]);
let out = cap[2].to_string();
(out, Operation::Direct(s1))
} else {
panic!("invalid instruction: {}", line.as_ref());
};
instructions.insert(out, operation);
}
Circuit { instructions }
}
fn lookup_signal(&mut self, wire: &str) -> u16 {
let res = match self.instructions.get(wire).unwrap().clone() {
Operation::Direct(s) => {
match s {
Signal::Raw(i) => i,
Signal::Wire(w) => self.lookup_signal(&w),
}
},
Operation::And(s1, s2) => {
let val1 = match s1 {
Signal::Raw(i) => i,
Signal::Wire(w) => self.lookup_signal(&w),
};
let val2 = match s2 {
Signal::Raw(i) => i,
Signal::Wire(w) => self.lookup_signal(&w),
};
val1 & val2
},
Operation::Or(s1, s2) => {
let val1 = match s1 {
Signal::Raw(i) => i,
Signal::Wire(w) => self.lookup_signal(&w),
};
let val2 = match s2 {
Signal::Raw(i) => i,
Signal::Wire(w) => self.lookup_signal(&w),
};
val1 | val2
},
Operation::Lshift(s, amnt) => {
let val = match s {
Signal::Raw(i) => i,
Signal::Wire(w) => self.lookup_signal(&w),
};
val << amnt
},
Operation::Rshift(s, amnt) => {
let val = match s {
Signal::Raw(i) => i,
Signal::Wire(w) => self.lookup_signal(&w),
};
val >> amnt
},
Operation::Not(s) => {
let val = match s {
Signal::Raw(i) => i,
Signal::Wire(w) => self.lookup_signal(&w),
};
val ^ 0xffff
},
};
self.instructions.insert(wire.to_string(), Operation::Direct(Signal::Raw(res)));
res
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test() {
let input = [
"123 -> x",
"456 -> y",
"x AND y -> d",
"x OR y -> e",
"x LSHIFT 2 -> f",
"y RSHIFT 2 -> g",
"NOT x -> h",
"NOT y -> i",
];
let mut circuit = Circuit::new(&input);
assert_eq!(circuit.lookup_signal("d"), 72);
assert_eq!(circuit.lookup_signal("e"), 507);
assert_eq!(circuit.lookup_signal("f"), 492);
assert_eq!(circuit.lookup_signal("g"), 114);
assert_eq!(circuit.lookup_signal("h"), 65412);
assert_eq!(circuit.lookup_signal("i"), 65079);
assert_eq!(circuit.lookup_signal("x"), 123);
assert_eq!(circuit.lookup_signal("y"), 456);
}
}
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