Advent of code 2021 day 17

import numba

def process1(s, part2=False):  # Fast with numba.
  x1, x2, y1, y2 = parse.parse(
      'target area: x={:d}..{:d}, y={:d}..{:d}', s).fixed

  @numba_njit(cache=True)
  def simulations(x1, x2, y1, y2):
    highest = -1000
    count = 0
    for dx0 in range(int(math.sqrt(x1)) if x1 > 0 else x1,
                     (-int(math.sqrt(-x2)) if x2 < 0 else x2) + 1):
      for dy0 in range(y1, max(abs(y1), abs(y2)) + 1):
        dx, dy = dx0, dy0
        x = y = 0
        max_y = 0
        while ((x <= x2 or dx < 0) and (x >= x1 or dx > 0) and
               (y >= y1 or dy > 0)):
          x, y = x + dx, y + dy
          max_y = max(max_y, y)
          dx, dy = dx - np.sign(dx), dy - 1
          if y1 <= y <= y2 and x1 <= x <= x2:
            count += 1
            highest = max(highest, max_y)
            break
    return count if part2 else highest

  return simulations(x1, x2, y1, y2)