From 7a0dc981c76ce7949b6594e3a81d733f0a8c6463 Mon Sep 17 00:00:00 2001
From: Tim Kurvers <tim@moonsphere.net>
Date: Wed, 11 Dec 2024 12:41:21 +0100
Subject: [PATCH] feat(js): add solutions for 2024 day 11

---
 js/src/2024/11/index.js       | 39 +++++++++++++++++++++++++++++++++++
 puzzles/2024/11/examples.yaml | 17 +++++++++++++++
 2 files changed, 56 insertions(+)
 create mode 100644 js/src/2024/11/index.js
 create mode 100644 puzzles/2024/11/examples.yaml

diff --git a/js/src/2024/11/index.js b/js/src/2024/11/index.js
new file mode 100644
index 0000000..a955537
--- /dev/null
+++ b/js/src/2024/11/index.js
@@ -0,0 +1,39 @@
+import { solution, sum } from '../../utils/index.js';
+
+const parse = (input) => input.trim().split(' ').map(Number);
+
+const blink = (stone, { times, cache = new Map() }) => {
+  // A stone is just a single stone at one point
+  if (times === 0) {
+    return 1;
+  }
+
+  const hash = `${stone}x${times}`;
+  if (cache.has(hash)) {
+    return cache.get(hash);
+  }
+
+  const opts = { times: times - 1, cache };
+
+  const str = String(stone);
+  let result;
+  if (stone === 0) {
+    result = blink(1, opts);
+  } else if (str.length % 2 === 0) {
+    result = blink(+str.slice(0, str.length / 2), opts) + blink(+str.slice(str.length / 2), opts);
+  } else {
+    result = blink(stone * 2024, opts);
+  }
+  cache.set(hash, result);
+  return result;
+};
+
+export const partOne = solution((input, { blinks: times = 25 }) => {
+  const stones = parse(input);
+  return sum(stones.map((stone) => blink(stone, { times })));
+});
+
+export const partTwo = solution((input, { blinks: times = 75 }) => {
+  const stones = parse(input);
+  return sum(stones.map((stone) => blink(stone, { times })));
+});
diff --git a/puzzles/2024/11/examples.yaml b/puzzles/2024/11/examples.yaml
new file mode 100644
index 0000000..c92ca57
--- /dev/null
+++ b/puzzles/2024/11/examples.yaml
@@ -0,0 +1,17 @@
+part-one:
+  - input: |
+      0 1 10 99 999
+    answer: 7
+    args:
+      blinks: 1
+
+  - input: &example1 |
+      125 17
+    answer: 22
+    args:
+      blinks: 6
+
+  - input: *example1
+    answer: 55312
+    args:
+      blinks: 25