SP112 SEGVIS - Horizontally Visible Segments

There is a number of disjoint vertical line segments in the plane. We say that two segments are horizontally visible if they can be connected by a horizontal line segment that does not have any common points with other vertical segments. Three different vertical segments are said to form a triangle of segments if each two of them are horizontally visible. How many triangles can be found in a given set of vertical segments? ### Task Write a program that: - reads the description of a set of vertical segments, - computes the number of triangles in this set, - writes the result.

The first line of the input contains exactly one positive integer d equal to the number of data sets, 1

The output should consist of exactly d lines, one line for each data set. Line i should contain exactly one integer equal to the number of triangles in the i-th data set.