2024 Day 24 Spelling, Indentation, and Doc comments

This commit is contained in:
Burnus 2025-01-05 10:39:04 +01:00
parent ababfcf16e
commit 0305b7caf0

View file

@ -193,10 +193,14 @@ fn is_loop_free(&self, name: &str, previous: &HashSet<&str>) -> bool {
} }
} }
/// Determines if the `idx`th least significant bit of z can be traced to input bits (x and y)
/// on all paths (returning `true`), or if they form a loop (returning `false`).
fn output_is_loop_free(&self, idx: usize) -> bool { fn output_is_loop_free(&self, idx: usize) -> bool {
self.is_loop_free(&Self::output_gate(idx)[..], &HashSet::new()) self.is_loop_free(&Self::output_gate(idx)[..], &HashSet::new())
} }
/// Checks if the rightmost `z_idx` bits of z behave like an adder. Returns `None`, if they do,
/// and `Some(idx)` otherwise, where `idx` is the first bit (from the right), which differs.
fn check_until(&mut self, z_idx: usize) -> Option<usize> { fn check_until(&mut self, z_idx: usize) -> Option<usize> {
let tests_0 = [(0, 0), (0, 1), (1, 0), (1, 1)]; let tests_0 = [(0, 0), (0, 1), (1, 0), (1, 1)];
if tests_0.iter().any(|(l, r)| { if tests_0.iter().any(|(l, r)| {
@ -226,6 +230,9 @@ fn is_loop_free(&self, name: &str, previous: &HashSet<&str>) -> bool {
}) })
} }
/// Try swapping all combinations of two gates, where at least one of them is contained in
/// `must_include` and none of them in `swapped_before` and determine if their swap results in
/// the rightmost `z_idx` bits of z are correct. Returns an unsorted Vec of all such pairs.
fn try_swaps(&'a mut self, z_idx: usize, must_include: &[&'a str], swapped_before: &[&'a str]) -> Vec<Vec<String>> { fn try_swaps(&'a mut self, z_idx: usize, must_include: &[&'a str], swapped_before: &[&'a str]) -> Vec<Vec<String>> {
let mut res = Vec::new(); let mut res = Vec::new();
// We need to clone these so the borrow checker won't complain about concurrent borrows in the // We need to clone these so the borrow checker won't complain about concurrent borrows in the
@ -237,7 +244,7 @@ fn is_loop_free(&self, name: &str, previous: &HashSet<&str>) -> bool {
if swapped_before.contains(&gate_1) { if swapped_before.contains(&gate_1) {
continue; continue;
} }
// The unwrap()s below are safe because the constructor made shure all gates exist. // The unwrap()s below are safe because the constructor made sure all gates exist.
let inputs_1 = *self.gates.get(gate_1).unwrap(); let inputs_1 = *self.gates.get(gate_1).unwrap();
for &gate_2 in all_inputs.iter().filter(|&&gate_2| for &gate_2 in all_inputs.iter().filter(|&&gate_2|
gate_2 != gate_1 && gate_2 != gate_1 &&
@ -256,6 +263,9 @@ fn is_loop_free(&self, name: &str, previous: &HashSet<&str>) -> bool {
res res
} }
/// Find the necessary (up to 8) swaps to turn this device into a binary adder.
/// `swapped_before` contains the swaps already established (this should be an empty array at
/// first). Returns a `Vec` of the affected gates, sorted alphabetically.
fn swap_gates(&mut self, swapped_before: &[String]) -> Vec<String> { fn swap_gates(&mut self, swapped_before: &[String]) -> Vec<String> {
let mut swaps_performed = swapped_before.to_vec(); let mut swaps_performed = swapped_before.to_vec();
loop { loop {
@ -266,7 +276,7 @@ fn swap_gates(&mut self, swapped_before: &[String]) -> Vec<String> {
let mut next = self.clone(); let mut next = self.clone();
let new_possible_swaps = next.try_swaps(next_error, &must_include, &swapped_before); let new_possible_swaps = next.try_swaps(next_error, &must_include, &swapped_before);
match new_possible_swaps.len() { match new_possible_swaps.len() {
// The unwrap()s below are safe because the constructor made shure all gates exist. // The unwrap()s below are safe because the constructor made sure all gates exist.
0 => return Vec::new(), // If we found no solution, return early 0 => return Vec::new(), // If we found no solution, return early
1 => { 1 => {
// We found one solution. Continue with it. // We found one solution. Continue with it.
@ -280,8 +290,8 @@ fn swap_gates(&mut self, swapped_before: &[String]) -> Vec<String> {
} }
}, },
_ => { _ => {
// We found more than one solution. Spawn a new Device for each and try // We found more than one solution.
// them all. // Spawn a new Device for each and try them all.
for swaps in new_possible_swaps { for swaps in new_possible_swaps {
if swaps.len() + swaps_performed.len() > 8 { if swaps.len() + swaps_performed.len() > 8 {
continue; continue;