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.

找一个二维图上在一条直线上点的最大数，不知道有啥更好的方法。

需要注意重复点的情况

class Solution {
public:
    int maxPoints(vector<Point> &points) {
        if(points.size()<=2) {
            //3个点以下
            return points.size();
        } else {
            int maxNum = 2;
            //选择一个点为出发点计算所有斜率
            for(vector<Point>::iterator point = points.begin(); point!=points.end(); ++point) {
                map<double,int> kMap;
                int numOfSame = 0; 
                for(vector<Point>::iterator otherPoint = points.begin(); otherPoint!=points.end(); ++otherPoint) {
                    //跳过出发点
                    if(otherPoint==point) continue; 
                    //记录重复点数量
                    if(otherPoint->x == point->x && otherPoint->y == point->y) {
                        ++numOfSame;
                        continue;
                    }
                    double k = otherPoint->x - point->x == 0 ?
                               numeric_limits<double>::max()
                               :(otherPoint->y - point->y)/(double)(otherPoint->x-point->x);
                    if(kMap.find(k)==kMap.end()) kMap[k]=0;
                    ++kMap[k];
                }

                auto tmpMax = max_element(kMap.begin(),kMap.end(),[&](pair<const double,int> &l,pair<const double,int> &r) {
                    return l.second < r.second;
                });

                maxNum = tmpMax!=kMap.end()?
                                 max(tmpMax->second+1+numOfSame,maxNum):
                                 max(1+numOfSame,maxNum);
            }
            return maxNum ;
        }
    }
};