1 int maxPoints(vector<Point> &points)  2     { 3         int max_points = 0, duplicate = 0; 4         unordered_map<float, int> htable; 5         double slope = 0; 6         int n = points.size(); 7         if (n <= 1) 8             return n; 9         10         for (int i = 0; i < n; i++)11         {12             duplicate = 1;13             htable.clear();14             for (int j = i + 1; j < n; j++)15             {16                 if ((points[i].x == points[j].x) && (points[i].y == points[j].y))17                 {    18                     duplicate++;19                     continue;20                 }21                 22                 slope = (points[i].x == points[j].x) ? INT_MAX : (float)(points[j].y - points[i].y) / (points[j].x - points[i].x);23                 htable[slope]++;24             }25             for (unordered_map<float, int>::iterator it = htable.begin(); it != htable.end(); it++)26             {27                 if (max_points < it->second + duplicate)28                     max_points = it->second + duplicate;29             }30             max_points = max(max_points, duplicate);31         }32         33         return max_points;34     }