AOC 2023 day 4 solve

aoc-2023-04.js

const { u } = require("../../tools/utils");

let input = "./input.txt";
//input = "./input_demo.txt";
const lines = u.readInputLines(input);

console.time("runtime");

const cards = lines
  .map((line) => line.split(":")[1])
  .map((line) =>
    line.split("|").map((subline) =>
      subline
        .trim()
        .replaceAll("  ", " ")
        .split(" ")
        .map((num) => Number(num))
    )
  );

// Part 1
const cardPoints = [];
const cardMatches = [];
const cardCounts = [];
for (const card of cards) {
  const wins = card[0].filter((winning) => card[1].includes(winning)).length;
  const points = wins > 1 ? Math.pow(2, wins - 1) : wins;
  cardPoints.push(points);
  cardMatches.push(wins);
  cardCounts.push(1);
}
console.log("Part 1:", cardPoints.reduce((a, c) => (a += c), 0));

// Part 2
for (i = 0; i < cardCounts.length; i++) {
  const wins = cardMatches[i];
  if (wins > 0) {
    for (j = i + 1; j < i + 1 + wins && j < cardCounts.length; j++) {
      cardCounts[j] += cardCounts[i];
    }
  }
}
console.log("Part 2:", cardCounts.reduce((a, c) => (a += c), 0));
console.timeEnd("runtime");