Max Points on a Line

class Solution {
public:
    int maxPoints(vector<Point>& points)
    {
        int maxNum = 0;
        if(points.size() < 3)return points.size();
        for(int i = 0;i < points.size();i++)
        {
            for(int j = i + 1;j < points.size();j++)
            {
                int temMax = 2;
                while(points[j].x == points[i].x && points[j].y == points[i].y)  //固定的两个点相同，则继续往下取，而且temMax加一
                {
                    j++;
                    if(j == points.size())
                        break;
                    temMax++;
                }
                for(int k = j + 1;k < points.size();k++)
                {
                    if(points[k].x == points[i].x && points[k].y == points[i].y)
                        temMax++;
                    else if(points[k].x == points[j].x  && points[k].y == points[j].y)
                        temMax++;
                    else if(getK(points[i], points[k]) == getK(points[i], points[j]))
                        temMax++;
                }
                if(temMax > maxNum)
                    maxNum = temMax;
            }
        }
        return  maxNum;
    }
private:
    double getK(Point a, Point b)
    {
        if(a.x == b.x)return MAX_INPUT;
        double k;
        k = (double)(a.y - b.y)/(double)(a.x - b.x);
        return k;
    }
};