The problem
Given $$$n$$$ points $$$(x_1, y_1),\ (x_2, y_2),\dots, (x_n, y_n)$$$
Find the minimum distance between 2 pair of points.
The problem: SPOJ
The constraint
$$$2 \leq n \leq 50000$$$
$$$x_i, y_i \leq 10^6$$$
My question
I was solving a problem that need to find the minimum distance between two points. I tried to bruteforce then cde an divide and conquer algorithm. But then I modified the bruteforce by adding some branch-and-bound to ignore not-optimal cases. For somehow my code get AC and seems to run fast while I thought it will be slow with the complexity of $$$O(n^2)$$$ with small constant.
I dont really sure about the complexity, can some one help me to calculate it ?
My main part
My full code
Same idea here.
Thank you so much.