Count Number of Trapezoids II
You receive a 2D integer array points where points[i] = [x i, y i ] represents the coordinates of the i th point on the Cartesian plane.
Produce the number of unique trapezoids that can be formed by choosing any four distinct points from points.
A trapezoid is a convex quadrilateral with at least one pair of parallel sides. Two lines are parallel if and only if they have the same slope.
Input: points = [[-3,2],[3,0],[2,3],[3,2],[2,-3]]
Output: 2
Explanation: There are two distinct ways to pick four points that form a trapezoid:
-
The points
[-3,2], [2,3], [3,2], [2,-3]form one trapezoid. -
The points
[2,3], [3,2], [3,0], [2,-3]form another trapezoid.
Input: points = [[0,0],[1,0],[0,1],[2,1]]
Output: 1
Explanation: There is only one trapezoid which can be formed.
Constraints
4 <= points.length <= 500–1000 <= x i, y i <= 1000- All points are pairwise distinct.
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