Solve 2025-06

2025/06/index.ts

@@ -0,0 +1,53 @@
+import { multArray, sumArray } from '../../utils/array.ts';
+
+function sumOrMultArray(op: string, nums: number[]) {
+  if (op === '*') {
+    return multArray(nums);
+  }
+  return sumArray(nums);
+}
+export function solveFirst(input: string): number {
+  const rows = input.split('\n');
+
+  const ops = rows.splice(-1)[0].replaceAll(' ', '').split('');
+  const parsed = rows.map((r) =>
+    Array.from(r.matchAll(/(\d+)/g), (m) => m.slice(1).map(Number)).flat()
+  );
+
+  return ops.reduce(
+    (s, op, i) =>
+      s +
+      sumOrMultArray(
+        op,
+        parsed.map((p) => p[i])
+      ),
+    0
+  );
+}
+
+export function solveSecond(input: string): number {
+  const rows = input.split('\n');
+  const longestRow = Math.max(...rows.map((r) => r.length));
+
+  const ops = rows.splice(-1)[0];
+
+  const cache: number[] = [];
+  let lastOp = '';
+  let sum = 0;
+
+  for (let i = 0; i < longestRow; i++) {
+    if (ops[i] === '*' || ops[i] === '+') {
+      sum += sumOrMultArray(lastOp, cache);
+      cache.length = 0;
+      lastOp = ops[i];
+    }
+
+    const digits = parseInt(rows.map((r) => r[i]).join(''));
+    if (!isNaN(digits)) {
+      cache.push(Number(digits));
+    }
+  }
+
+  sum += sumOrMultArray(lastOp, cache);
+  return sum;
+}