<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) {
        unordered_map<int, unordered_set<int>> xmap;
        for (const auto& point : points) {
            xmap[point[0]].insert(point[1]);
        }

        int minArea = INT_MAX;
        for (auto& kv1 : xmap) {
            for (auto& kv2 : xmap) {
                const auto &x1 = kv1.first;
                const auto &x2 = kv2.first;
                if (x1 == x2) continue;

                vector<int> commonYs;
                for (const auto& y : kv1.second) {
                    if (kv2.second.count(y)) {
                        commonYs.push_back(y);
                    }
                }

                if (commonYs.size() >= 2) {
                    sort(commonYs.begin(), commonYs.end());
                    for (int i = 1; i < commonYs.size(); ++i) {
                        int height = commonYs[i] - commonYs[i - 1];
                        int width = abs(x2 - x1);
                        int area = width * height;
                        minArea = min(minArea, area);
                    }
                }
            }
        }

        return minArea == INT_MAX ? 0 : minArea;
    }

};
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