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compare: ktims:9a6ca66059670910a1646c32334bb2259699edb7
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1 changed files with 12 additions and 14 deletions
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src/day18.rs
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@ -51,12 +51,10 @@ impl MemoryMap {
Self { map, byte_stream } Self { map, byte_stream }
} }
// Return if the byte caused a new blockage or not fn place_byte(&mut self, i: usize) {
fn place_byte(&mut self, i: usize) -> bool {
let pos = self.byte_stream[i]; let pos = self.byte_stream[i];
match self.map.set(&pos, false) { if self.map.set(&pos, false).is_none() {
None => panic!("corruption outside memory bounds"), panic!("corruption outside memory bounds");
Some(x) => x,
} }
} }
fn place_bytes(&mut self, n: usize) { fn place_bytes(&mut self, n: usize) {
@ -128,18 +126,18 @@ pub fn part2_impl(input: &str, width: usize, height: usize, n: usize) -> (i64, i
input_map.place_bytes(n); input_map.place_bytes(n);
let mut path = input_map.dijkstra::<Vec<(i64, i64)>>((0, 0)).expect("no path found"); let mut path = input_map.dijkstra::<Vec<(i64, i64)>>((0, 0)).expect("no path found");
println!("{:?}", path);
for byte in n..input_map.byte_stream.len() { for byte in n..input_map.byte_stream.len() {
if input_map.place_byte(byte) { input_map.place_byte(byte);
// If it's a new blockage, and it obstructs our best path, we need to do a new path search
if let Some((obs_at, _)) = path.iter().find_position(|v| *v == &input_map.byte_stream[byte]) {
let (before, _) = path.split_at(obs_at);
if let Some(new_path) = input_map.dijkstra::<Vec<(i64, i64)>>(path[obs_at - 1]) { if let Some((obs_at, _)) = path.iter().find_position(|v| *v == &input_map.byte_stream[byte]) {
path = [before, &new_path].concat(); let (before, _) = path.split_at(obs_at);
} else {
return input_map.byte_stream[byte]; if let Some(new_path) = input_map.dijkstra::<Vec<(i64, i64)>>(path[obs_at - 1]) {
} path = [before, &new_path].concat();
} else {
return input_map.byte_stream[byte];
} }
} }
} }