func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int t;     cin >> t;     while (t--) {       int n;       cin >> n;       int a[n];       for (int i = 0; i < n; ++i) {         cin >> a[i];       }       for (int i = n - 1; i >= 0; --i) {         int temp = i % 2 != 0 ? -a[i] : a[i];         cout << temp <<    ;       }       cout << endl;     }   }   