1384A Common Prefixes.cpp

#include <bits/stdc++.h>
 
using namespace std;

template<class C> void mini(C&a, C b){ a=min(a, b);}
template<class C> void maxi(C&a, C b){a=max(a,b);}
#define sz(x) x.size()
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define mt make_tuple
#define forall(it,s) for(auto it = s.begin(); it != s.end(); ++it)
#define F0(i,n) for(int i = 0; i < n; i++)
#define F1(i,n) for(int (i) = 1; i <= n; i++)
#define F0R(i,n) for(int (i) = n-1; i >= 0; i--)
#define F1R(i,n) for(int (i) = n; i >= 1; i--)
#define REP(i,a,b) for(int i = a; i <= b; i++)
#define REPR(i,a,b) for(int i = a; i >= b; i--)
#define INF 1e9
#define todo(v) v.begin(),v.end()
#define eps 0.000000000001
#define mod 1000000007
#define PI acos(-1.0)
#define ll long long

void solve(){
	int n;
	cin >> n;
	vector<int> a(n);
	F0(i,n) cin >> a[i];
	int low = 'z' - 'a';
	vector<char> let(low);
	F0(i,low) let[i] = 'a' + i;
	string buf = "";
	ll cont = 0;
	while(cont < 50){
		buf += let[cont%low];
		cont++;
	}
	cout << buf << endl;
	for(int i = 0; i<n; i++){
		string newbuf = "";
		for(int j=0; j<a[i]; j++){
			newbuf += buf[j];
		}
		if(let[cont%low] == buf[a[i]]){
			cont++;
		}
		for(int j=a[i]; j<50; j++){
			newbuf += let[cont%low];
			cont++;
		}
		buf = newbuf;
		cout << buf << endl;
	}
}
int main(){
	int t;
	cin >> t;
	while(t--) solve();
	return 0;
}