1 /**
2 * Definition for a point.
3 * struct Point {
4 * int x;
5 * int y;
6 * Point() : x(0), y(0) {}
7 * Point(int a, int b) : x(a), y(b) {}
8 * };
9 */
10 class Solution {
11 public:
12 /**
13 * @param points an array of point
14 * @return an integer
15 */
16 int maxPoints(vector<Point>& points) {
17 // Write your code here
18 unordered_map<float, int> slopes;
19 int maxp = 0, n = points.size();
20 for (int i = 0; i < n; i++) {
21 slopes.clear();
22 int duplicate = 1;
23 for (int j = i + 1; j < n; j++) {
24 if (points[i].x == points[j].x && points[i].y == points[j].y) {
25 duplicate++;
26 continue;
27 }
28 float slope = (points[i].x == points[j].x) ? INT_MAX:
29 (float)(points[i].y - points[j].y) / (points[i].x - points[j].x);
30 slopes[slope]++;
31 }
32 maxp = max(maxp, duplicate);
33 for (auto slope : slopes)
34 if (slope.second + duplicate > maxp)
35 maxp = slope.second + duplicate;
36 }
37 return maxp;
38 }
39 };
