func_code_string: #include <bits/stdc++.h>   using namespace std;   long long mod = 1000000007;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     long long n;     cin >> n;     long long a[n], b[n], c[n];     for (long long i = 0; i < n; i++) {       cin >> a[i];     }     for (long long i = 0; i < n; i++) cin >> b[i];     for (long long i = 0; i < n; i++) {       c[i] = (a[i] - b[i]);     }     sort(c, c + n);     long long answer = 0, answer1 = 0;     for (long long i = 0; i < n; i++) {       long long ans = a[i] - b[i];       long long sum = 1 - ans;       if (ans > 0) answer1++;       long long ss = lower_bound(c, c + n, sum) - c;       answer += (n - ss);     }     answer -= answer1;     answer /= 2;     cout << answer << endl;     return 0;   }   