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: 2Explanation: 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.

  一個函數(shù)計算2個點的尺寸，然后2個循環(huán)算出所有點之間的尺寸，map存儲，然后根據(jù)相同數(shù)量，就能算出來

Runtime:?187 ms, faster than?65.29%?of?Java?online submissions for?Number of Boomerangs.

Memory Usage:?109.6 MB, less than?68.56%?of?Java?online submissions for?Number of Boomerangs.