func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 2e5 + 10;   int T, n, a[N];   map<int, int> mp;   int main() {     cin >> T;     while (T--) {       double sum = 0;       mp.clear();       cin >> n;       for (int i = 0; i < n; ++i) {         cin >> a[i];         sum += a[i];       }       double mean = sum / n;       double need = sum - (n - 2) * mean;       if (need != floor(need)) {         cout << 0 << endl;         continue;       }       long long ans = 0;       for (int i = 0; i < n; ++i) {         if (mp.find(need - a[i]) != mp.end()) ans += mp[need - a[i]];         mp[a[i]]++;       }       cout << ans << endl;     }     return 0;   }   