Rectangles#424
On the plane, there are several rectangles. Each rectangle is specified by the coordinates of its lower left corner (x_1, y_1) and upper right corner (x_2, y_2) , with sides parallel to the coordinate axes. When rectangles are placed on top of each other, they form shapes; an individual rectangle is also considered a shape. Rectangles that touch only at corners do not form a shape. If rectangles touch at sides, they form a shape as well. Determine the shape with the maximum area (output the area of such a shape).
The first line contains the number of test cases.
The first line of each test case contains the number of rectangles , followed by lines with the coordinates of the vertices of the rectangles x_1\ y_1\ x_2\ y_2. The coordinates of the vertices are integers, nonnegative numbers from to inclusive. The number of rectangles does not exceed .
For each test case, output the computed area on a separate line.
Example 1