feat(js): add solutions for 2024 day 11

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 })));
+});

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