Input: points = [[1,1],[2,2],[3,3]]
Output: 0
Explanation:
There is no way to choose A and B so A is on the upper left side of B.
You are given a 2D array points of size n x 2 representing integer coordinates of some points on a 2D plane, where points[i] = [xi, yi].
Count the number of pairs of points (A, B), where
A is on the upper left side of B, andReturn the count.
Example 1:
Input: points = [[1,1],[2,2],[3,3]]
Output: 0
Explanation:
There is no way to choose A and B so A is on the upper left side of B.
Example 2:
Input: points = [[6,2],[4,4],[2,6]]
Output: 2
Explanation:
(points[1], points[0]), where points[1] is on the upper left side of points[0] and the rectangle is empty.(points[2], points[1]), same as the left one it is a valid pair.(points[2], points[0]), where points[2] is on the upper left side of points[0], but points[1] is inside the rectangle so it's not a valid pair.Example 3:
Input: points = [[3,1],[1,3],[1,1]]
Output: 2
Explanation:
(points[2], points[0]), where points[2] is on the upper left side of points[0] and there are no other points on the line they form. Note that it is a valid state when the two points form a line.(points[1], points[2]), it is a valid pair same as the left one.(points[1], points[0]), it is not a valid pair as points[2] is on the border of the rectangle.
Constraints:
2 <= n <= 50points[i].length == 20 <= points[i][0], points[i][1] <= 50points[i] are distinct.