func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int t;     cin >> t;     while (t--) {       int arr[102];       int n;       cin >> n;       for (int i = 1; i <= n; i++) cin >> arr[i];       int myseq[102];       for (int i = 1; i <= n; i++) {         if (i & 1)           myseq[i] = arr[i + 1];         else           myseq[i] = -arr[i - 1];       }       for (int i = 1; i <= n; i++) cout << myseq[i] <<    ;       cout << endl;     }     return 0;   }   