leetcode Max Points on a Line(*)

Given n points
on a 2D plane, find the maximum number of points that lie on the same straight line.
求平面内共线最多的点，统计与某一点斜率相同的其它点的数量，求最多数量的统计。这里注意斜率为无穷(垂直直线)和两个点相同的情况。

/**
* 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) {
if(points.size()<=2)return points.size();
map<double,int> kmap;
int equalNum,verNum,curMax,maxNum=0;
for(int i=0;i<points.size();i++){
kmap.clear();equalNum=1;verNum=1;curMax=0;
for(int j=i+1;j<points.size();j++){
if(points[j].x==points[i].x){
verNum++;
if(points[j].y==points[i].y)equalNum++;
}else{
double k=1.0*(points[j].y-points[i].y)/(points[j].x-points[i].x);
if(kmap.find(k)!=kmap.end())kmap[k]++;
else kmap.insert(make_pair(k,1));
if(curMax<kmap[k])curMax=kmap[k];
}
}
if(maxNum<curMax+equalNum)maxNum=curMax+equalNum;
if(maxNum<verNum)maxNum=verNum;
}
return maxNum;
}
};