Leetcode 223. rectangular area

Here you are. A two-dimensional Two on the plane It is composed of straight lines and the edge is parallel to the coordinate axis / vertical The rectangular , Please calculate and return the total area covered by two rectangles .

Each rectangle is defined by its The lower left Vertex sum The upper right Vertex coordinates represent ：

• The first rectangle consists of its lower left vertex (ax1, ay1) And the top right vertex (ax2, ay2) Definition .
• The second rectangle consists of its lower left vertex (bx1, by1) And the top right vertex (bx2, by2) Definition .

Example 1：

 Input ：ax1 = -3, ay1 = 0, ax2 = 3, ay2 = 4