#include <bits/stdc++.h>
using namespace std;
template <typename T>
void set_max(T& a, T b) {
  a = max(a, b);
}
template <typename T>
void set_min(T& a, T b) {
  a = min(a, b);
}
template <typename A, typename B>
string to_string(pair<A, B> p);
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);
string to_string(const string& s) { return '"' + s + '"'; }
string to_string(const char* s) { return to_string((string)s); }
string to_string(bool b) { return (b ? "true" : "false"); }
string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}
template <size_t N>
string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}
template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto& x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}
template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ")";
}
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}
void solve() {
  int n;
  cin >> n;
  vector<int> a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  map<int, int> mp;
  map<int, int> mx;
  for (int i = 0; i < n; i++) {
    if (mp.count(a[i])) {
      int dist = i - mp[a[i]] - 1;
      mx[a[i]] = max(mx[a[i]], dist);
    } else {
      int dist = i;
      mx[a[i]] = dist;
    }
    mp[a[i]] = i;
  }
  42;
  for (auto& [value, prev] : mp) {
    int dist = n - prev - 1;
    mx[a[prev]] = max(mx[a[prev]], dist);
  }
  42;
  int inf = 1e9;
  vector<int> from(n + 1, inf);
  for (auto& [value, dist] : mx) {
    set_min(from[dist + 1], value);
  }
  int mn = inf;
  for (int k = 1; k <= n; k++) {
    set_min(mn, from[k]);
    if (k > 1) cout << " ";
    cout << (mn == inf ? -1 : mn);
  }
  cout << '\n';
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int tt;
  cin >> tt;
  while (tt--) {
    solve();
  }
  return 0;
}
