Question

Find the total area covered by two rectilinear rectangles in a 2D plane.

Each rectangle is defined by its bottom left corner and top right corner as shown in the figure.

Paste_Image.png

Assume that the total area is never beyond the maximum possible value of int.

Code

public class Solution {
    public int computeArea(int A, int B, int C, int D, int E, int F, int G, int H) {
        int area = (C - A) * (D - B) + (G - E) * (H - F);
        
        if (E > C || F > D || A > G || B > H) return area;
        
        area -= (Math.min(C, G) - Math.max(A, E)) * (Math.min(D, H) - Math.max(B, F));
        return area;
    }
}

Solution

（1）计算两个长方形的面积之和。
（2）判断是否有重复区域。
（3）减去重复区域的面积。