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

MinimumAreaRectangles.cpp

class Solution {
public:
    int minAreaRect(vector<vector<int>>& points) {
        if(points.size() < 4)
            return 0;
        unordered_map <int, unordered_map<int, bool>> side;
        
        for(int i = 0; i < points.size(); i++) {
            side[points[i][0]][points[i][1]] = true;            
        }
        
        int ans = numeric_limits<int>::max();
        int x1, x2, x3, x4;
        int y1, y2, y3, y4;
         for(int i = 0; i < points.size(); i++) {
            for(int j = i + 1; j < points.size(); j++) {
                int a = abs(points[j][0] - points[i][0]);
                int b = abs(points[j][1] - points[i][1]);
                                              
                if(!(a == 0 or b == 0)) {
                    
                    x1 = points[i][0];
                    y1 = points[i][1];

                    x2 = x1 + a;

                    y3 = y1 - b;

                    x4 = x1 + a;
                    y4 = y1 - b;
                    if(side[x1][y1] and side[x2][y1] and side[x1][y3] and side[x4][y4]) {
                        ans = min(ans, a*b);
                    }
                
                    x2 = x1 - a;

                    y3 = y1 + b;

                    x4 = x1 - a;
                    y4 = y1 + b;

                    if(side[x1][y1] and side[x2][y1] and side[x1][y3] and side[x4][y4]) {
                        ans = min(ans, a*b);
                    }
                }
                
            }
        }
        if(ans == numeric_limits<int>::max())
            return 0;
        return ans;
        
        
            
    }
};