text: 
  
  #ifndef __NUMBER_OF_BOOMERANGS_H
  #define __NUMBER_OF_BOOMERANGS_H
  
  #include <iostream>
  #include <vector>
  #include <map>
  #include <queue>
  #include <math.h>
  #include <stack>
  #include <set>
  #include <map>
  #include <unordered_map>
  #include <algorithm>
  #include <stdint.h>
  
  using namespace std;
  
  static int x = []() {
      ios::sync_with_stdio(false); // cin与stdin禁止同步
      cin.tie(NULL);               //cin与cout解除绑定
      return 0;
  }();
  
  class Solution {
  public:
  int numberOfBoomerangs(vector<pair<int, int>>& points) {
          int booms = 0;
          for (auto &p : points) {
          unordered_map<int, int> ctr(points.size());
          for (auto &q : points)
              booms += 2 * ctr[pow((p.first - q.first),2) + 
                  pow((p.second - q.second),2)]++;
          }
          return booms;
      }
  };
  
  #endif
  
  
  