func_code_string: #include <bits/stdc++.h>   using namespace std;   const double PI = 2 * acos(0.0);   void fastInOut();   int power(int z, int i) {     int zz = 1;     for (int k = 0; k < i; k++) {       zz *= z;     }     return zz;   }   long long power(long long x, long long y) {     long long z = 1;     for (long long i = 0; i < y; i++) z *= x;     return z;   }   unsigned long long power(unsigned long long b, unsigned long long pow) {     if (b == 0)       return 0;     else if (pow == 1)       return b;     else if (pow % 2 == 0)       return power(b * b, pow / 2);     else       return b * power(b * b, pow / 2);   }   int main() {     fastInOut();     int n, x, y, res1 = 0, res2 = 0, sum = 0;     cin >> n;     vector<pair<int, int>> v;     while (n--) {       cin >> x >> y;       v.push_back({x, y});     }     int arr[100000] = {0};     arr[2] = 1;     for (int i = 3; i < 100000; i++) arr[i] = arr[i - 1] + (i - 1);     for (int i = 1; i <= 1000; i++) {       res1 = res2 = 0;       for (int k = 0; k < v.size(); k++) {         if (1 + i == v[k].first + v[k].second) res1++;         if (1 - i == v[k].first - v[k].second) res2++;       }       sum += (arr[res1] + arr[res2]);       res1 = res2 = 0;       if (i > 1 && i < 1000) {         for (int k = 0; k < v.size(); k++) {           if (1000 + i == v[k].first + v[k].second) res1++;           if (1000 - i == v[k].first - v[k].second) res2++;         }       }       sum += (arr[res1] + arr[res2]);     }     cout << sum;   }   void fastInOut() {     ios_base::sync_with_stdio(0);     cin.tie(NULL), cout.tie(NULL);   }   