<p>Given an array of <code>points</code> where <code>points[i] = [x<sub>i</sub>, y<sub>i</sub>]</code> represents a point on the <strong>X-Y</strong> plane, return <em>the maximum number of points that lie on the same straight line</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/02/25/plane1.jpg" style="width: 300px; height: 294px;" />
<pre>
<strong>Input:</strong> points = [[1,1],[2,2],[3,3]]
<strong>Output:</strong> 3
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/02/25/plane2.jpg" style="width: 300px; height: 294px;" />
<pre>
<strong>Input:</strong> points = [[1,1],[3,2],[5,3],[4,1],[2,3],[1,4]]
<strong>Output:</strong> 4
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= points.length &lt;= 300</code></li>
	<li><code>points[i].length == 2</code></li>
	<li><code>-10<sup>4</sup> &lt;= x<sub>i</sub>, y<sub>i</sub> &lt;= 10<sup>4</sup></code></li>
	<li>All the <code>points</code> are <strong>unique</strong>.</li>
</ul>

class Solution {
public:
    int maxPoints(vector<vector<int>>& points) {
        const int n = points.size();
        if(n == 1) return 1;
        
        vector<set<pair<int, int>>> s;
        int maxp = 0;
        for(int i = 0; i < n; i++){
            unordered_map<string, int> m;
            for(int j = i + 1; j < n; j++){
                int p1x = points[i][0], p1y = points[i][1];
                int p2x = points[j][0], p2y = points[j][1];
                string slope;
                if(p1x - p2x == 0){
                    slope = "y " + to_string(p1x);
                }
                else{
                    double x = p1y - p2y == 0 ? 0.0 : (double)(p1y - p2y) / (double)(p1x - p2x);
                    double c = x * p1x - p1y;
                    stringstream ss;
                    ss.precision(10);
                    ss << x << " " << c;
                    slope = ss.str();
                }
                
                // if(m.find(slope) == m.end()){
                //     set<pair<int, int>> sm;
                //     sm.insert({p1x, p1y});
                //     sm.insert({p2x, p2y});
                //     m[slope] = s.size();
                //     s.push_back(sm);                    
                // }
                // else{
                //     s[m[slope]].insert({p1x, p1y});
                //     s[m[slope]].insert({p2x, p2y});
                // }
                // maxp = max(maxp, int(s[m[slope]].size()));
                if(m.find(slope) == m.end()) m[slope]++;
                m[slope]++;
                maxp = max(maxp, m[slope]);
                cout << slope <<" @ "<<m[slope]<<endl;
                // cout << x <<"x - y = "<<c<<endl;
                // cout<< "["<<p1x<<" "<<p1y<<"], ["<<p2x<<" "<<p2y<<"]\n";
            }
        }
        // for(auto &[mp, cnt] : m){
        //     cout << mp.first << " " << mp.second << " " << cnt << endl;
        // }
        return maxp;
    }
};
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