func_code_string: #include <bits/stdc++.h>   using namespace std;   int a[100010];   int main() {     int t;     cin >> t;     while (t--) {       int n;       cin >> n;       for (int i = 0; i < n; i++) cin >> a[i];       sort(a, a + n);       int i = (n - 1) / 2, j = i + 1;       while (i >= 0 || j <= n - 1) {         if (i >= 0) cout << a[i--] <<    ;         if (j <= n - 1) cout << a[j++] <<    ;       }       cout << endl;     }     return 0;   }   