Java | Leetcode Java题解之第447题回旋镖的数量
题目：
题解：
class Solution {
public int numberOfBoomerangs(int[][] points) {
int ans = 0;
for (int[] p : points) {
Map<Integer, Integer> cnt = new HashMap<Integer, Integer>();
for (int[] q : points) {
int dis = (p[0] - q[0]) * (p[0] - q[0]) + (p[1] - q[1]) * (p[1] - q[1]);
cnt.put(dis, cnt.getOrDefault(dis, 0) + 1);
}
for (Map.Entry<Integer, Integer> entry : cnt.entrySet()) {
int m = entry.getValue();
ans += m * (m - 1);
}
}
return ans;
}
}