/**
 * Regards an IP address as a number with 4 digits.
 * Each digit can be between 0 and 255.
 * The result of this function is the total number of possible IPs 'lower' than the given IP.
 */
const ipToNum = (ip: string): number => {
  const digits = ip.split('.').map(Number) as [number, number, number, number];
  console.log(digits);
  if(digits.length !== 4) {
    throw new Error('Invalid IP address');
  }
  return digits.reduce((sum, digit) => sum * 256 + digit, 0);
}

export function ipsBetween(start: string, end: string): number {
  return ipToNum(end) - ipToNum(start);
}