leetcode

0 class Solution {

1 static int distance(const vector<int> &a, const vector<int> &b) {

2 return pow(b[0] - a[0], 2) + pow(b[1] - a[1], 2);

3 }

4

5 public:

6 int numberOfBoomerangs(const vector<vector<int>> &points) const {

7 const int n = size(points);

8 int res = 0;

9

10 for (int i = 0; i < n; i++) {

11 unordered_map<int, int> um;

12

13 for (int j = 0; j < n; j++) {

14 if (i == j) continue;

15 um[distance(points[i], points[j])]++;

16 }

17

18 for (const auto [_, cnt] : um) {

19 if (cnt == 1) continue;

20 res += cnt * (cnt - 1);

21 }

22 }

23

24 return res;

25 }

26 };