int visiblePoints(int[][] points) {
    int maxMatches = 0;
    double diff;
    int matches = 0;
    int length = points.Length;
    if (length == 1)
        return 1;
    double[] phi = new double[length];

    for(int i = 0; i < length; i++)
    {
        phi[i] =  Math.Atan((double) points[i][1]/points[i][0]);
        if (points[i][0]<=0)
        {
            phi[i] += Math.PI;
        }
    }

    Array.Sort(phi);
    int j;

    for(int i = 0; i < length; i++)
    {
        j = 0;
        while (inView(phi[i],phi[(i+j)%length]))
        {
            j++;
        }
        if (matches < j)

            matches = j;
    }

    return matches;
}

bool inView(double point, double target)
{
    double diff = target-point;
    return (diff < Math.PI/4 + 0.00000000000001 && diff >= 0);
}