const fs = require('fs/promises'); const sum = (arr) => arr.reduce((total, num) => total+num, 0); const arrayOfLength = n => Array.from(Array(n).keys()).map(() => {}); const parseXY = str => str.match(/x=(.*), y=(.*)$/).slice(1).map(x => BigInt(x)); const ROW = 2000000n; const abs = x => x < 0n ? x * -1n : x; const main = async () => { const input = (await fs.readFile("./input.txt", 'utf8')).split("\n").slice(0, -1); console.log(input); const sets = input.map(row => row.split(": ").map(parseXY)); const map = new Set(); const getDistance = (x1, y1, x2, y2) => abs(x1 - x2) + abs(y1 - y2); const fillRow = (centerX, radius) => { console.log("Fill radius: ", radius); for(let i = centerX - radius; i <= centerX + radius; ++i) { map.add(i); } } for(let [[x, y], b] of sets) { const radius = getDistance(x, y, ...b); const halfWidth = radius - abs(ROW - y) if(halfWidth > 0) { fillRow(x, halfWidth); } } for(let [_, b] of sets) { if(b[1] === ROW) { map.delete(b[0]); } } console.log("ANSWER: ", map.size); } main();