func_code_string: #include <bits/stdc++.h>   using namespace std;   map<int, int> cnt1, cnt2;   const int maxn = 1e5 * 3;   int x[maxn];   int y[maxn];   int main() {     int n = 0;     cin >> n;     for (int i = 0; i < n; i++) {       cin >> x[i] >> y[i];       cnt1[x[i] - y[i]]++;       cnt2[x[i] + y[i]]++;     }     long long ans = 0;     for (int i = 0; i < n; i++) {       long long c1 = cnt1[x[i] - y[i]];       long long c2 = cnt2[x[i] + y[i]];       ans += c1 + c2 - 2;     }     cout << ans / 2;   }   