Just-Zzz Sqrt(x)

public int (int x) {
    if (x == 1 || x == 0)
        return x;
    long begin = 0, end = x / 2 ;
    while (begin + 1 < end) {
        long mid = begin + (end - begin) / 2;
        long mul = mid * mid;
        if (mul == x)
            return (int)mid;
        if (mul < x)
            begin = (int)mid;
        else
            end = (int)mid;
    }
    if (end * end <= x)
        return (int)end;
    return (int)begin;
}

public int (int x) {
    long begin = 0, end = x;
    while (begin + 1 < end) {
        long mid = begin + (end - begin) / 2;
        long mul = mid * mid;
        if (mul == x)
            return (int)mid;
        if (mul < x)
            begin = (int)mid;
        else
            end = (int)mid;
    }
    if (end * end <= x)
        return (int)end;
    return (int)begin;
}