chore: y2025::day_11

Author: clechasseur

aoclp_solutions/src/lib.rs

@@ -11,5 +11,5 @@ pub mod y2025;
 build_solvers! {
     { 2017, [01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25] },
     { 2024, [01, 02, 03, 04, 05, 06, 07, 08, 09, 10] },
-    { 2025, [01, 02, 03, 04, 05, 06, 07, 08, 09, 10] }
+    { 2025, [01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 11] }
 }

aoclp_solutions/src/y2025/day_11.rs

@@ -0,0 +1,77 @@
+use std::collections::HashMap;
+use std::str::FromStr;
+use std::sync::OnceLock;
+
+use aoclp::anyhow::Context;
+use aoclp::regex::Regex;
+use aoclp::solvers_impl::input::safe_get_input_as_many;
+use itertools::Itertools;
+
+pub fn part_1() -> usize {
+    let devices = devices_map();
+    let mut cache = HashMap::new();
+    num_paths(&devices, "you", true, true, &mut cache)
+}
+
+pub fn part_2() -> usize {
+    let devices = devices_map();
+    let mut cache = HashMap::new();
+    num_paths(&devices, "svr", false, false, &mut cache)
+}
+
+fn devices_map() -> HashMap<String, Vec<String>> {
+    input().into_iter().map(|d| (d.name, d.outputs)).collect()
+}
+
+fn num_paths(
+    devices: &HashMap<String, Vec<String>>,
+    cur: &str,
+    dac: bool,
+    fft: bool,
+    cache: &mut HashMap<(String, bool, bool), usize>,
+) -> usize {
+    if let Some(num) = cache.get(&(cur.to_string(), dac, fft)) {
+        return *num;
+    }
+    if cur == "out" {
+        return if dac && fft { 1 } else { 0 };
+    }
+
+    let (dac, fft) = (dac || cur == "dac", fft || cur == "fft");
+    let outputs = &devices[cur];
+    let num = outputs
+        .iter()
+        .map(|d| num_paths(devices, d, dac, fft, cache))
+        .sum();
+    cache.insert((cur.to_string(), dac, fft), num);
+    num
+}
+
+#[derive(Debug, Clone)]
+struct Device {
+    name: String,
+    outputs: Vec<String>,
+}
+
+impl FromStr for Device {
+    type Err = aoclp::Error;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        static REGEX: OnceLock<Regex> = OnceLock::new();
+        let re =
+            REGEX.get_or_init(|| Regex::new(r"^(?<name>\w+):\s+(?<outputs>(?:\w+\s*)+)$").unwrap());
+
+        let captures = re
+            .captures(s)
+            .with_context(|| format!("invalid device spec: {s}"))?;
+        let name = &captures["name"];
+        let outputs = &captures["outputs"];
+        let outputs = outputs.split_ascii_whitespace().map_into().collect_vec();
+
+        Ok(Self { name: name.into(), outputs })
+    }
+}
+
+fn input() -> Vec<Device> {
+    safe_get_input_as_many(2025, 11)
+}

aoclp_solutions/src/y2025/mod.rs

@@ -8,3 +8,4 @@ pub mod day_07;
 pub mod day_08;
 pub mod day_09;
 pub mod day_10;
+pub mod day_11;