day17.js

const fs = require('fs').promises;

(async () => {
  console.log(`Reading input from ${__dirname}/${process.argv[2]}.txt`);
  const inputData = await fs.readFile(`${__dirname}/${process.argv[2]}.txt`);
  const inputs = inputData
    .toString()
    .split('\n')
    .filter((n) => n);

  let grid = new Map();
  inputs.forEach((line, x) => {
    line.split('').forEach((item, y) => {
      grid.set(`[${x}, ${y}, 0]`, item);
    });
  });

  let cycle = 0;
  let xBounds = [0, inputs.length];
  let yBounds = [0, inputs.length];
  let zBounds = [0, 1];
  while (cycle < 6) {
    const nextGrid = new Map();
    xBounds = [xBounds[0] - 1, xBounds[1] + 1];
    yBounds = [yBounds[0] - 1, yBounds[1] + 1];
    zBounds = [zBounds[0] - 1, zBounds[1] + 1];

    for (let x = xBounds[0]; x < xBounds[1]; x++) {
      for (let y = yBounds[0]; y < yBounds[1]; y++) {
        for (let z = zBounds[0]; z < zBounds[1]; z++) {
          let numActive = 0;

          for (const dX of [-1, 0, 1]) {
            for (const dY of [-1, 0, 1]) {
              for (const dZ of [-1, 0, 1]) {
                if (dX === 0 && dY === 0 && dZ === 0) {
                  continue;
                }
                if (grid.get(`[${x + dX}, ${y + dY}, ${z + dZ}]`) === '#') {
                  numActive++;
                }
              }
            }
          }

          const value = grid.get(`[${x}, ${y}, ${z}]`);
          if (numActive === 3) {
            nextGrid.set(`[${x}, ${y}, ${z}]`, '#');
          } else if (value === '#' && numActive === 2) {
            nextGrid.set(`[${x}, ${y}, ${z}]`, '#');
          }
        }
      }
    }

    grid = nextGrid;
    cycle++;
  }

  console.log('part1', [...grid.values()].filter((i) => i === '#').length);

  let grid2 = new Map();
  inputs.forEach((line, x) => {
    line.split('').forEach((item, y) => {
      grid2.set(`[${x}, ${y}, 0, 0]`, item);
    });
  });

  let cycle2 = 0;
  let xBounds2 = [0, inputs.length];
  let yBounds2 = [0, inputs.length];
  let zBounds2 = [0, 1];
  let hyperBounds2 = [0, 1];
  while (cycle2 < 6) {
    const nextGrid = new Map();
    xBounds2 = [xBounds2[0] - 1, xBounds2[1] + 1];
    yBounds2 = [yBounds2[0] - 1, yBounds2[1] + 1];
    zBounds2 = [zBounds2[0] - 1, zBounds2[1] + 1];
    hyperBounds2 = [hyperBounds2[0] - 1, hyperBounds2[1] + 1];

    for (let x = xBounds2[0]; x < xBounds2[1]; x++) {
      for (let y = yBounds2[0]; y < yBounds2[1]; y++) {
        for (let z = zBounds2[0]; z < zBounds2[1]; z++) {
          for (let h = hyperBounds2[0]; h < hyperBounds2[1]; h++) {
            let numActive = 0;

            for (const dX of [-1, 0, 1]) {
              for (const dY of [-1, 0, 1]) {
                for (const dZ of [-1, 0, 1]) {
                  for (const dH of [-1, 0, 1]) {
                    if (dX === 0 && dY === 0 && dZ === 0 && dH === 0) {
                      continue;
                    }
                    if (
                      grid2.get(
                        `[${x + dX}, ${y + dY}, ${z + dZ}, ${h + dH}]`
                      ) === '#'
                    ) {
                      numActive++;
                    }
                  }
                }
              }
            }

            const value = grid2.get(`[${x}, ${y}, ${z}, ${h}]`);
            if (numActive === 3) {
              nextGrid.set(`[${x}, ${y}, ${z}, ${h}]`, '#');
            } else if (value === '#' && numActive === 2) {
              nextGrid.set(`[${x}, ${y}, ${z}, ${h}]`, '#');
            }
          }
        }
      }
    }

    grid2 = nextGrid;
    cycle2++;
  }

  console.log('part2', [...grid2.values()].filter((i) => i === '#').length);
})();