Number of Boomerangs

arrayhash tablemath

Problem Statement

You are given n points in the plane that are all distinct , where points[i] = [x _i , y _i ] . 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 .

Examples

Example 1

Input: points = [[0,0],[1,0],[2,0]]
Output: 2
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

-10 ^4 <= x _i , y _i <= 10 ^4

All the points are unique .

🤔

Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicHash Table