class Solution {
public:
int maxPoints(vector<Point>& points) {
int res = 0;
for (int i = 0; i < points.size(); ++i) {
map<pair<int, int>, int> m;
int duplicate = 1;
for (int j = i + 1; j < points.size(); ++j) {
if (points[i].x == points[j].x && points[i].y == points[j].y) {
++duplicate; continue;
}
int dx = points[j].x - points[i].x;
int dy = points[j].y - points[i].y;
int d = gcd(dx, dy);
++m[{dx / d, dy / d}];
}
res = max(res, duplicate);
for (auto it = m.begin(); it != m.end(); ++it) {
res = max(res, it->second + duplicate);
}
}
return res;
}
int gcd(int a, int b) {
return (b == 0) ? a : gcd(b, a % b);
}
};