Number of Boomerangs

Given n points in the plane that are all pairwise distinct, 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).

Find the number of boomerangs. You may assume that n will be at most 500 and coordinates of points are all in the range [-10000, 10000] (inclusive).

Example:
Input:
[[0,0],[1,0],[2,0]]

Output:

Explanation:
The two boomerangs are [[1,0],[0,0],[2,0]] and [[1,0],[2,0],[0,0]]

public int numberOfBoomerangs(int[][] points) {
    int res = 0;

    Map<Integer, Integer> map = new HashMap<>();
    for(int i=0; i<points.length; i++) {
        for(int j=0; j<points.length; j++) {
            if(i == j)
                continue;

            int d = getDistance(points[i], points[j]);
            map.put(d, map.getOrDefault(d, 0) + 1);
        }

        for(int val : map.values()) {
            res += val * (val-1);
        }
        map.clear();
    }

    return res;
}

private int getDistance(int[] a, int[] b) {
    int dx = a[0] - b[0];
    int dy = a[1] - b[1];

    return dx*dx + dy*dy;
}