<p>You are given an array of points in the <strong>X-Y</strong> plane <code>points</code> where <code>points[i] = [x<sub>i</sub>, y<sub>i</sub>]</code>.</p>

<p>Return <em>the minimum area of a rectangle formed from these points, with sides parallel to the X and Y axes</em>. If there is not any such rectangle, return <code>0</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/08/03/rec1.JPG" style="width: 500px; height: 447px;" />
<pre>
<strong>Input:</strong> points = [[1,1],[1,3],[3,1],[3,3],[2,2]]
<strong>Output:</strong> 4
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/08/03/rec2.JPG" style="width: 500px; height: 477px;" />
<pre>
<strong>Input:</strong> points = [[1,1],[1,3],[3,1],[3,3],[4,1],[4,3]]
<strong>Output:</strong> 2
</pre>

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

<ul>
	<li><code>1 &lt;= points.length &lt;= 500</code></li>
	<li><code>points[i].length == 2</code></li>
	<li><code>0 &lt;= x<sub>i</sub>, y<sub>i</sub> &lt;= 4 * 10<sup>4</sup></code></li>
	<li>All the given points are <strong>unique</strong>.</li>
</ul>

class Solution {
public:

 
    int minAreaRect(vector<vector<int>>& points) {
        long long n = 200000;
        unordered_map<long long, vector<long long >> hor_lines;
        for (int i = 0; i < points.size(); ++i) {
            for (int u = i + 1; u < points.size(); ++u) {
                if (points[i][1] != points[u][1]) {
                    continue;
                }
                long long xx;
                if (points[i][0] < points[u][0]) {
                    xx = points[i][0] * n + points[u][0];
                }
                else {
                    xx = points[u][0] * n + points[i][0];
                }
                hor_lines[xx].push_back(points[i][1]);
            }
        }
        long long res = n * n;
        for ( auto &e : hor_lines) {
            long long hash = e.first;
            long long x1 = hash / n;
            long long x2 = hash % n;
            long long side1 = x2 - x1;
            assert(side1 > 0);
            vector<long long> &y_s = e.second;
            sort(y_s.begin(), y_s.end());
            for (int i = 0; i < y_s.size() - 1; ++i) {
                long long side2 = y_s[i + 1] - y_s[i];

                assert(side2 > 0);
                //cout << abs(side1 * side2) << endl;
                res = min(res, side1 * side2); 
            }
        }
        if (res == n * n) {
            res = 0;
        }
        return res;
    }
};
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