Files
adventofcode2025/02/code.js
2025-12-02 12:56:37 -05:00

66 lines
1.7 KiB
JavaScript

import { readFileSync } from 'node:fs';
// const inputArray = readFileSync('sample.txt').toString().split(",");
const inputArray = readFileSync('input.txt').toString().split(",");
// Part One
console.time("part1");
let sum = 0;
for (const element of inputArray) {
const contents = element.split("-");
const start = Number.parseInt(contents[0]);
const end = Number.parseInt(contents[1]);
for (let sku = start; sku <= end; sku++) {
const skuString = sku.toString();
const digits = skuString.length
if (digits % 2 === 0) {
if (skuString.slice(0, digits / 2) === skuString.slice(digits / 2)) {
sum += sku;
}
}
}
}
console.timeEnd("part1");
console.log(sum);
// Part Two
console.time("part2");
let sum2 = 0;
const repeats = [];
for (const element of inputArray) {
const contents = element.split("-");
const start = Number.parseInt(contents[0]);
const end = Number.parseInt(contents[1]);
for (let sku = start; sku <= end; sku++) {
const skuString = sku.toString();
const digits = skuString.length
const maxRepeatLength = Math.floor(digits / 2);
for (let repeatLength = 1; repeatLength <= maxRepeatLength; repeatLength++) {
if (digits % repeatLength === 0) {
const maxRepeats = digits / repeatLength;
const repeatPattern = skuString.slice(0, repeatLength);
const repeatedPattern = repeatPattern.repeat(maxRepeats);
if (repeatedPattern === skuString) {
repeats.push(sku);
}
}
}
}
}
const uniqueRepeats = [...new Set(repeats)];
for (const repeat of uniqueRepeats) {
sum2 += Number.parseInt(repeat);
}
console.timeEnd("part2");
console.log(sum2);
// functions