|Author:||A. Baranov||Time limit:||1 sec|
|Input file:||Standard input||Memory limit:||512 Mb|
|Output file:||Standard output|
Consider a set of N two-dimensional points represented by their coordinates (Xi, Yi).
It is required to determine the number of all possible rectangles that satisfy the following conditions:
Input starts with integer N,
followed by 2 × N integers, representing point coordinates: Xi, Yi.
The output should contain
the number of detected rectangles.
All input points are different.
− 106 ≤ (Xi, Yi) ≤ 106,
4 ≤ N ≤ 105
|No.||Standard input||Standard output|