aoc-2024/day1-puzzle1.ts

import fs from "node:fs";

const input = fs.readFileSync("inputs/day1").toString();

const sort = (a: number, b: number) => a - b;

const lists: number[][] = [];

input.split("\n").forEach(line => {
    line.split(/\s+/g).forEach((i, list) => {
        lists[list] = lists[list] || [];
        lists[list].push(Number(i));
    })
})

lists.forEach(i => i.sort(sort));

const rows: number[] = [];

lists[0].forEach((a, i) => {
    const nums = [a, lists[1][i]].sort(sort); 
    rows.push(nums[1] - nums[0]);
})

const result = rows.reduce((prev, cur) => prev + cur);

console.log(result);