[LeetCode] Rectangle Area

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.

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

Credits:
Special thanks to @mithmatt for adding this problem, creating the above image and all test cases.

数学题，求矩形覆盖面积。因为只有两个矩形，所以直接算结果 = 两个矩形的面积 - 相交的面积。估计下一道题就会是求多个矩形的覆盖面积了吧。

1 class Solution {
2 public:
3     int computeArea(int A, int B, int C, int D, int E, int F, int G, int H) {
4         int res = (D - B) * (C - A) + (H - F) * (G - E);
5         int A1 = max(A, E), B1 = max(B, F), C1 = min(C, G), D1 = min(D, H);
6         if (D1 <= B1 || C1 <= A1) return res;
7         return res - (D1 - B1) * (C1 - A1);
8     }
9 };