Advent of Code 2023 - Day 21 - Part 1

const wrapped = (i, j, size) => {
  i %= size;
  j %= size;
  return {
    wi: i >= 0 ? i : size + i,
    wj: j >= 0 ? j : size + j,
  };
};
const getNextSteps = (grid, i, j, remaining) => {
  const k = key(i, j);
  const { wi, wj } = wrapped(i, j, grid.size);
  const wk = key(wi, wj);

  if (grid.walls[wk] || grid.plots[k] >= remaining) {
    return [];
  }
  grid.plots[k] = remaining;
  if (remaining > 0) {
    return [
      { i: i + 1, j: j, remaining: remaining - 1 },
      { i: i - 1, j: j, remaining: remaining - 1 },
      { i: i, j: j + 1, remaining: remaining - 1 },
      { i: i, j: j - 1, remaining: remaining - 1 },
    ];
  }
  return [];
};
const solvePart1 = (input, steps = 64) => {
  const grid = parse(input);
  const queue = [
    {
      i: grid.start.i,
      j: grid.start.j,
      remaining: steps,
    },
  ];
  while (queue.length > 0) {
    const step = queue.shift();
    queue.push(...getNextSteps(grid, step.i, step.j, step.remaining));
  }
  return Object.values(grid.plots).filter((e) => e % 2 == 0).length;
};