/*
Description:
While surfing in web I found interesting math problem called "Always perfect". That means if you add 1 to the product of four consecutive numbers the answer is ALWAYS a perfect square. For example we have: 1,2,3,4 and the product will be 1X2X3X4=24. If we add 1 to the product that would become 25, since the result number is a perfect square the square root of 25 would be 5.

So now lets write a function which takes numbers separated by commas in string format and returns the number which is a perfect square and the square root of that number.

If string contains other characters than number or it has more or less than 4 numbers separated by comma function returns "incorrect input".

If string contains 4 numbers but not consecutive it returns "not consecutive".
*/
function checkRoot(string) {
  const arr = string.split(",").map(v => v * 1);
  if (arr.some(v => isNaN(v) || v === 0) || arr.length !== 4)
    return "incorrect input";
  const sum = arr.reduce((a, b) => a * b, 1);
  if (
    arr.map((v, i, arr) => arr[i] + 1 === arr[i + 1]).filter(v => v === false)
      .length > 1
  )
    return "not consecutive";
  return `${sum + 1}, ${Math.sqrt(sum + 1)}`;
}
