func_code_string: #include <bits/stdc++.h>   using namespace std;   struct HashMap {     vector<pair<int, int> > g[1000007];     void ins(int x, int y) {       int id = ((long long)x * 1000000007 + y) % 1000007;       g[id].push_back(make_pair(x, y));     }     bool get(int x, int y) {       int id = ((long long)x * 1000000007 + y) % 1000007;       for (int i = 0; i < g[id].size(); i++)         if (g[id][i].first == x && g[id][i].second == y) return true;       return false;     }   };   int n;   HashMap mp;   vector<int> row[100011];   vector<int> rateB;   int main() {     scanf( %d , &n);     for (int i = 1; i <= n; i++) {       int x, y;       scanf( %d%d , &x, &y);       row[y].push_back(x);       mp.ins(x, y);     }     int di = (int)sqrt(n);     long long int ans = 0;     for (int a = 0; a <= 100000; a++) {       if (row[a].size() != 0) {         sort(row[a].begin(), row[a].end());         if (row[a].size() <= di) {           for (int i = 0; i < row[a].size(); i++) {             for (int j = i + 1; j < row[a].size(); j++) {               int x1 = row[a][i];               int x2 = row[a][j];               int dis = x2 - x1;               if (mp.get(x1, a + dis) && mp.get(x2, a + dis)) ans++;               if (a - dis >= 0 && row[a - dis].size() > di &&                   (mp.get(x1, a - dis) && mp.get(x2, a - dis)))                 ans++;             }           }         } else           rateB.push_back(a);       }     }     for (int i = 0; i < rateB.size(); i++) {       for (int j = i + 1; j < rateB.size(); j++) {         int a = rateB[i];         int b = rateB[j];         int u = 0, p = 0;         int dis = b - a;         while (u < row[a].size() && p < row[b].size()) {           if (row[a][u] < row[b][p])             u++;           else if (row[a][u] > row[b][p])             p++;           else {             int x1 = row[a][u];             if (mp.get(x1 + dis, a) && mp.get(x1 + dis, b)) ans++;             u++;             p++;           }         }       }     }     printf( %I64d n , ans);     return 0;   }   