leetcode 447 Number of Boomerangs

class Solution {
public:
    int numberOfBoomerangs(vector<vector<int>>& points) {
        int re=0;
        for(int i=0;i<points.size();++i) {
            unordered_map<int,int> m;
            for(int j=0;j<points.size();++j) {
                if(i==j) continue;
                int dis=(points[i][0]-points[j][0])*(points[i][0]-points[j][0])+(points[i][1]-points[j][1])*(points[i][1]-points[j][1]);
                ++m[dis];
            }
            for(auto& t:m) {
                if(t.second==1) continue;
                int ans=t.second*(t.second-1);
                re+=ans;
            }
        }
        return re;
    }
};