给你 二维 平面上两个 由直线构成且边与坐标轴平行/垂直 的矩形，请你计算并返回两个矩形覆盖的总面积。

每个矩形由其 左下 顶点和 右上 顶点坐标表示： 第一个矩形由其左下顶点 (ax1, ay1) 和右上顶点 (ax2, ay2) 定义。 第二个矩形由其左下顶点 (bx1, by1) 和右上顶点 (bx2, by2) 定义。

var computeArea = function(ax1, ay1, ax2 , ay2, bx1, by1, bx2, by2) {const area1 = (ax2 - ax1) * (ay2 - ay1), area2 = (bx2 - bx1) * (by2 - by1);const overlapWidth = Math.min(ax2, bx2) - Math.max(ax1, bx1), overlapwidth = Math.min(ay2, by2) - Math.max(ay1, by1);const overlapArea = Math.max(overlapWidth, 0) * Math.max(overlapHeight, 0);return areal + area2 - overlapArea;
};

示例1：输入：ax1 = -3, ay1 = 0, ax2 = 3, ay2 = 4, bx1 = 0, by1 = -1, bx2 = 9, by2 = 2输出：45
示例2：输入：ax1 = -2, ay1 = -2, ax2 = 2, ay2 = 2, bx1 = -2, by1 = -2, bx2 = 2, by2 = 2输出：16