#include <bits/stdc++.h>
using namespace std;
priority_queue<long long int, vector<long long int>, greater<long long int> >
    ti;
vector<long long int> p[200005], y[300005], f(200005, 0), b(100005, 0);
long long int vis[100005];
map<pair<long long int, long long int>, long long int> mp;
set<pair<long long int, long long int> > s;
set<long long int> st;
map<long long int, long long int> np, v;
queue<long long int> qy;
long long int gcd(long long int a, long long int b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long int bpow(long long int a, long long int b) {
  long long int res = 1;
  while (b > 0) {
    if (b & 1) res = (res * a) % 1000000007;
    a = (a * a) % 1000000007;
    b >>= 1;
  }
  return res % 1000000007;
}
void fact(long long int i) {
  f[0] = 1;
  for (long long int k = 1; k <= i; k++) {
    (f[k] = f[k - 1] * k) %= 1000000007;
  }
}
long long int isprime(long long int n) {
  if (n == 1) return 0;
  for (long long int i = 2; i <= sqrt(n); i++)
    if (n % i == 0) return 0;
  return 1;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int t;
  cin >> t;
  while (t--) {
    long long int n;
    cin >> n;
    vector<long long int> a(n), b(n);
    for (long long int i = 0; i < n; i++) {
      cin >> a[i];
    }
    map<long long int, long long int> mp;
    vector<long long int> p;
    while (true) {
      mp.clear();
      long long int c = 0;
      for (long long int i = 0; i < n; i++) {
        mp[a[i]] = 1;
      }
      while (mp[c] == 1) c++;
      b = a;
      sort(b.begin(), b.end());
      if (b == a) break;
      if (c > n - 1) {
        long long int f;
        for (long long int i = 0; i < n; i++) {
          if (a[i] > i) {
            f = i;
          }
        }
        a[f] = c;
        p.push_back(f + 1);
      } else {
        p.push_back(c + 1);
        a[c] = c;
      }
    }
    cout << p.size() << "\n";
    for (long long int i = 0; i < p.size(); i++) {
      cout << p[i] << " ";
    }
    cout << "\n";
  }
}
