2025 11.2

Author: Lexicality

data

@@ -26,7 +26,10 @@ const fn to_id(input: &str) -> Key {
     ((a as u32) << 16) + ((b as u32) << 8) + (c as u32)
 }
 
-const START: Key = to_id("you");
+const YOU: Key = to_id("you");
+const SERVER: Key = to_id("svr");
+const FFT: Key = to_id("fft");
+const DAC: Key = to_id("dac");
 const END: Key = to_id("out");
 
 fn parse_line(input: String) -> crate::AoCResult<(Key, Vec<Key>)> {
@@ -53,7 +56,56 @@ cached_key! {
 
 pub fn part_1(data: crate::DataIn) -> crate::AoCResult<String> {
     let store: Store = data.map(parse_line).try_collect()?;
-    let ret = find_paths(START, &store);
+    let ret = find_paths(YOU, &store);
+    Ok(ret.to_string())
+}
+
+#[derive(Debug, Hash, Clone, Copy, PartialEq, Eq, Default)]
+struct PathState {
+    found_fft: bool,
+    found_dac: bool,
+}
+
+impl PathState {
+    fn get_score(&self) -> usize {
+        if self.found_dac && self.found_fft {
+            1
+        } else {
+            0
+        }
+    }
+}
+
+cached_key! {
+    FIND_PATHS_2: UnboundCache<(Key, PathState), usize> = UnboundCache::with_capacity(600);
+    Key = { (id, path_state) };
+    fn find_paths_2(id: Key, path_state: PathState, store: &Store) -> usize = {
+        let mut path_state = path_state;
+        if id == FFT {
+            path_state.found_fft = true;
+        } else if id == DAC{
+            path_state.found_dac = true;
+        }
+        let my_outputs = &store[&id];
+        log::debug!("Hello I'm {id} and my friends are {my_outputs:?}");
+
+        my_outputs
+            .iter()
+            .copied()
+            .map(|out_id| {
+                if out_id == END {
+                    path_state.get_score()
+                } else {
+                    find_paths_2(out_id, path_state, store)
+                }
+            })
+            .sum::<usize>()
+    }
+}
+
+pub fn part_2(data: crate::DataIn) -> crate::AoCResult<String> {
+    let store: Store = data.map(parse_line).try_collect()?;
+    let ret = find_paths_2(SERVER, Default::default(), &store);
     Ok(ret.to_string())
 }
 
@@ -62,7 +114,16 @@ inventory::submit!(crate::AoCDay {
     day: "11",
     part_1: crate::AoCPart {
         main: part_1,
-        example: part_1
+        example: |data| {
+            let (data, _) = crate::partition_input(data);
+            part_1(data)
+        }
     },
-    part_2: None
+    part_2: Some(crate::AoCPart {
+        main: part_2,
+        example: |data| {
+            let (_, data) = crate::partition_input(data);
+            part_2(data)
+        }
+    })
 });