func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 2000 + 10;   const int maxm = 4e5 + 10;   const long long mod = 1e9 + 7;   const int inf = 0x3f3f3f3f;   const double eps = 1e-5;   const double pi = acos(-1.0);   int t;   int n, a[maxn];   int cnt[maxn];   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     cin >> t;     while (t--) {       cin >> n;       vector<int> res;       for (int i = 0; i <= n; i++) cnt[i] = 0;       for (int i = 0; i < n; i++) {         cin >> a[i];         cnt[a[i]]++;       }       int now;       while (1) {         now = 0;         bool flag = false;         for (int i = 1; i < n; i++)           if (a[i] < a[i - 1]) flag = true;         if (flag == false) break;         for (int i = 0; i < n; i++) {           if (cnt[i])             now = i + 1;           else             break;         }         if (now == n) {           int index = 0, minnum = maxn;           for (int i = 0; i < n; i++)             if (a[i] != i) {               if (a[i] < minnum) {                 index = i;                 minnum = a[i];               }             }           int p = a[index];           cnt[p]--;           cnt[now]++;           a[index] = now;           res.push_back(index);           continue;         }         int p = a[now];         cnt[p]--;         cnt[now]++;         a[now] = now;         res.push_back(now);       }       cout << res.size() << endl;       for (int i = 0; i < res.size(); i++) cout << res[i] + 1 <<    ;       cout << endl;     }     return ~~(0 - 0);   }   