[LeetCode] 939. Minimum Area Rectangle 面积最小的矩形

If there isn‘t any rectangle, return 0.

Example 1:

Input: [[1,1],[1,3],[3,1],[3,3],[2,2]]
Output: 4

Example 2:

Input: [[1,1],[1,3],[3,1],[3,3],[4,1],[4,3]]
Output: 2

Note:

1. 1 <= points.length <= 500
2. 0 <=?points[i][0] <=?40000
3. 0 <=?points[i][1] <=?40000
4. All points are distinct.

class Solution {
public:
    int minAreaRect(vector<vector<int>>& points) {
        int res = INT_MAX, n = points.size();
        unordered_map<int, unordered_set<int>> m;
        for (auto point : points) {
            m[point[0]].insert(point[1]);
        }
        for (int i = 0; i < n; ++i) {
            for (int j = i + 1; j < n; ++j) {
                if (points[i][0] == points[j][0] || points[i][1] == points[j][1]) continue;
                if (m[points[i][0]].count(points[j][1]) && m[points[j][0]].count(points[i][1])) {
                    res = min(res, abs(points[i][0] - points[j][0]) * abs(points[i][1] - points[j][1]));
                }   
            }
        }
        return res == INT_MAX ? 0 : res;
    }
};

https://github.com/grandyang/leetcode/issues/939

https://leetcode.com/problems/minimum-area-rectangle/

https://leetcode.com/problems/minimum-area-rectangle/discuss/192025/Java-N2-Hashmap

https://leetcode.com/problems/minimum-area-rectangle/discuss/192026/C%2B%2B-hashmap-%2B-set-intersection

[LeetCode] 939. Minimum Area Rectangle 面积最小的矩形

原文：https://www.cnblogs.com/grandyang/p/12689148.html