func_code_string: #include <bits/stdc++.h>   using namespace std;   long long a[1010];   long long b[1010];   long long c[2020];   long long d[1010];   long long mex(long long m) {     sort(b, b + m);     long long j = 0;     long long k = 0;     long long ans = m;     while (j < m) {       if (b[k] > j) {         ans = j;         break;       } else if (b[k] == j) {         k++;         j++;       } else {         k++;       }     }     return ans;   }   long long check(long long m) {     long long ct3 = 0;     for (long long i = 1; i < m; i++) {       if (a[i] < a[i - 1]) {         ct3 = 1;         break;       }     }     if (ct3 == 1)       return 0;     else       return 1;   }   int main() {     long long t;     cin >> t;     while (t--) {       long long n;       cin >> n;       long long ct = 1;       long long ct1 = 0;       for (long long i = 0; i <= n; i++) {         a[i] = 0;         b[i] = 0;         c[i] = 0;         d[i] = 0;       }       for (long long i = n; i <= (n + n); i++) {         c[i] = 0;       }       for (long long i = 0; i < n; i++) {         cin >> a[i];         b[i] = a[i];         if (a[i] == i) d[i] = 1;       }       while (ct <= (2 * n)) {         if (check(n) == 1) break;         ct1 = mex(n);         if (ct1 == n) {           for (long long i = 0; i < n; i++) {             if (d[i] != 1) {               a[i] = n;               c[ct] = i;               break;             }           }         } else {           c[ct] = ct1;           a[ct1] = ct1;           d[ct1] = 1;         }         for (long long i = 0; i < n; i++) b[i] = a[i];         ct++;       }       cout << ct - 1 <<   n ;       for (long long i = 1; i < ct; i++) {         cout << c[i] + 1 <<    ;       }       cout <<   n ;     }     return 0;   }   