Solve 2025-02

2025/02/index.ts

@@ -0,0 +1,34 @@
+import type { Coordinate, Coordinates } from '../../utils/coordinates.ts';
+
+function parseInput(input: string) {
+  const regex = /(\d*)-(\d*)/gm;
+  const match = input.matchAll(regex);
+
+  return Array.from(match, (m) => [Number(m[1]), Number(m[2])] as Coordinate);
+}
+
+export function sumMatches(ranges: Coordinates, foundRegex: RegExp) {
+  return ranges.reduce((s, range) => {
+    for (let i = range[0]; i <= range[1]; i++) {
+      if (foundRegex.test(String(i))) {
+        s += i;
+      }
+    }
+
+    return s;
+  }, 0);
+}
+
+export const findSingleRepetition = /^(\d*?)\1$/;
+export function solveFirst(input: string): number {
+  const ranges = parseInput(input);
+
+  return sumMatches(ranges, findSingleRepetition);
+}
+
+export const findMultiRepetition = /^(\d*?)\1+$/;
+export function solveSecond(input: string): number {
+  const ranges = parseInput(input);
+
+  return sumMatches(ranges, findMultiRepetition);
+}