#include <bits/stdc++.h>
using namespace std;
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long t;
  cin >> t;
  while (t--) {
    long long n;
    cin >> n;
    long long a[n];
    for (long long i = 0; i < n; i++) cin >> a[i];
    string s[200];
    for (long long i = 0; i < 101; i++) s[0].push_back('a');
    for (long long i = 1; i < n + 1; i++) {
      s[i] = s[i - 1];
      if (s[i][a[i - 1]] == 'a')
        s[i][a[i - 1]] = 'b';
      else
        s[i][a[i - 1]] = 'a';
    }
    for (long long i = 0; i < n + 1; i++) {
      cout << s[i] << "\n";
    }
  }
  return 0;
}
