Solve 2024-25

2024/25/index.ts

@@ -0,0 +1,35 @@
+import { sumArray, sumBy } from '../../utils/array.ts';
+
+type KeyLock = number[];
+
+function checkKeyLock(lock: KeyLock, key: KeyLock, max = 5) {
+  if (lock.length !== key.length) {
+    return false;
+  }
+  return lock.every((d, i) => d + key[i] <= max);
+}
+
+export function solveFirst(input: string): number {
+  const [keys, locks] = input.split('\n\n').reduce(
+    (combinations, b) => {
+      const rows = b.split('\n');
+      const isLock = b[0][0] === '#' ? 1 : 0;
+      const comb: KeyLock = [];
+      for (let i = 0; i < rows[0].length; i++) {
+        const column = rows.flatMap((r) => r[i]);
+        comb.push(column.filter((c) => c === '#').length - 1);
+      }
+      combinations[isLock].push(comb);
+      return combinations;
+    },
+    [[], []] as [KeyLock[], KeyLock[]]
+  );
+  // const locks = blocks.filter((b) => b[0][0] === '#');
+  // const key = blocks.filter((b) => b[0][0] === '.');
+
+  const found = locks.map((l) =>
+    sumBy(keys, (k) => (checkKeyLock(l, k) ? 1 : 0))
+  );
+
+  return sumArray(found);
+}