func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 100010, maxm = maxn * 2;   int h[maxn], ne[maxm], e[maxm], cnt;   int d[maxn], dp[maxn][3], w[maxn], root;   int a[maxn];   int vis[maxn];   void solve() {     int T;     scanf( %d , &T);     while (T--) {       int n;       scanf( %d , &n);       for (int i = 1; i <= n; i++) {         scanf( %d , &a[i]);       }       for (int i = 1; i < n; i += 2) {         cout << -a[i + 1] <<     << a[i] <<    ;       }       cout << endl;     }     return;   }   int main() {     solve();     return 0;   }   