#include<iostream>
#include<vector>
int t;
using namespace std;
int main(){
    cin >> t;
    while (t--){
        int n; cin >> n;
        vector <int> a(n + 1);
        for (int i = 1; i < n + 1; ++i) cin >> a[i];
        vector <string> s(n + 2);
        string t(200, 'a'); s[0] = t;
        for (int i = 1; i < n + 2; ++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 (int i = 1; i < s.size(); ++i)
            cout << s[i] << endl;
    }
}