def is_square(positive_int):
    """
    Quick function to find if a number is a perfect square root

    Parameters
    ----------
    positive_int : int
        The number evaluated.

    Returns
    ----------
    bool : bool
        If true, the number is a perfect square root.

    """
    x = positive_int // 2
    seen = set([x])
    while x * x != positive_int:
        x = (x + (positive_int // x)) // 2
        if x in seen:
            return False
        seen.add(x)
    return True