[Algorithom] Valid IP address

function validIPAddresses(string) {
  const res= []
  for (let i = 1; i < Math.min(string.length, 4); i++) {
    const parts = ['', '', '', '']
    parts[0] = string.slice(0, i)
    if (!isPossible(parts[0])) {
      continue 
    }
    for (let j = i + 1; j < i + Math.min(string.length - i, 4); j++) {
      parts[1] = string.slice(i, j)
       if (!isPossible(parts[1])) {
          continue 
       }

      for (let k = j + 1; k < j + Math.min(string.length - j, 4); k++) {
        parts[2] = string.slice(j, k)
        parts[3] = string.slice(k)

        if (isPossible(parts[2]) && isPossible(parts[3])) {
          res.push(parts.join('.'))
        }
      }
    }
  }

  return res;
}

function isPossible(str) {
  const val = parseInt(str, 10)
  if (val > 255) {
    return false
  }

  return str.length === val.toString().length
}