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();