#include <bits/stdc++.h>
using namespace std;
void solve() {
  int n;
  cin >> n;
  int a[n];
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  int cont = 1;
  string init(51, 'a');
  vector<string> ans(n + 1);
  ans[0] = init;
  for (int i = 0; i < n; i++) {
    string temp = ans[i];
    int idx = temp[a[i]];
    idx++;
    if (idx - 'a' >= 26) idx -= 26;
    temp[a[i]] = idx;
    ans[i + 1] = temp;
  }
  for (string s : ans) cout << s << "\n";
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int t;
  cin >> t;
  while (t--) solve();
}
