public class Solution
extends Object
447 - Number of Boomerangs\.
Medium
You are given `n` `points` in the plane that are all **distinct** , where points[i] = [xi, yi]. A **boomerang** is a tuple of points `(i, j, k)` such that the distance between `i` and `j` equals the distance between `i` and `k` **(the order of the tuple matters)**.
Return _the number of boomerangs_.
**Example 1:**
**Input:** points = \[\[0,0],[1,0],[2,0]]
**Output:** 2
**Explanation:** The two boomerangs are [[1,0],[0,0],[2,0]] and [[1,0],[2,0],[0,0]].
**Example 2:**
**Input:** points = \[\[1,1],[2,2],[3,3]]
**Output:** 2
**Example 3:**
**Input:** points = \[\[1,1]]
**Output:** 0
**Constraints:**
* `n == points.length`
* `1 <= n <= 500`
* `points[i].length == 2`
* -104 <= xi, yi <= 104
* All the points are **unique**.