Max Points on a Line

/**
 * Definition for a point.
 * struct Point {
 *     int x;
 *     int y;
 *     Point() : x(0), y(0) {}
 *     Point(int a, int b) : x(a), y(b) {}
 * };
 */
class Solution {
public:
    int maxPoints(vector<Point> &points) {
        int n = points.size(); //number of the points
        if (n<=2){return n;}   
        vector<double> k; //vector to store the slops for one point with all the other points
        int res = 0;
         
        for (int i=0;i<n;i++){ // for each point in the 2d plane
            k.clear();
            int dup = 1; // number of the duplicates with currrent point
            for (int j=0;j<n;j++){ 
                if (i!=j){ // for every other point
                    if (points[i].x-points[j].x==0){ // if the slope is a vertical line
                        if (points[i].y-points[j].y==0){ // if the point j is the same as point i
                            dup++;  
                        }else{
                            k.push_back(99999); //store the vertical line to a specific slope
                        }
                    }else{ // if it is the regular slop between point i and j
                        k.push_back(10000*(points[i].y-points[j].y)/(points[i].x-points[j].x)); // store the slope
                    }
                }
            }
             
            sort(k.begin(),k.end()); //sort the slopes for counting
             
            int pp = 1; //number of points in the same line of the point i
            if (k.size()==0){pp=0;} 
 
            for (int jj=1;jj<k.size();jj++){ //count pp
                if (k[jj]==k[jj-1]){
                    pp++;
                }else{
                    if (pp+dup>res){res=pp+dup;} // res = pp + the number of duplicates
                    pp = 1;
                }
            }
            if (pp+dup>res){res = pp+dup;}
        }
 
        return res;
    }
};